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CHEWTADZY (tadalafil) is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Tadalafil has the empirical formula C22H19N3O4 representing a molecular weight of 389.41. The structural formula is:
 |
The chemical designation is pyrazino[1´,2´:1,6]pyrido[3,4-b]indole-1,4-dione, 6-(1,3-benzodioxol-5-yl)Â2,3,6,7,12,12a-hexahydro-2-methyl-, (6R,12aR)-. It is a crystalline solid that is practically insoluble in water and very slightly soluble in ethanol.
CHEWTADZY is available as round-shaped, blue colored (mottled), biconvex uncoated, chewable tablets for oral administration. Each tablet contains 5, 10, or 20 mg of tadalafil and the following inactive ingredients: Bubblegum flavor (acacia, artificial and natural flavors), colloidal silicon dioxide, croscarmellose sodium, FD&C blue No. 1 aluminum lake, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate, mannitol, microcrystalline cellulose, sodium lauryl sulfate and sucralose.
CHEWTADZY™ is indicated for the treatment of erectile dysfunction (ED) in adult males.
CHEWTADZY is indicated for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH) in adult males.
CHEWTADZY is indicated for the treatment of ED and the signs and symptoms of BPH (ED/BPH) in adult males.
The recommended dosage for benign prostatic hyperplasia (BPH) is 5 mg orally once daily. Take at approximately the same time daily.
When used concomitantly with finasteride, the recommended CHEWTADZY dosage is 5 mg orally once daily for up to 26 weeks. Take at approximately the same time daily.
The recommended dosage for Erectile Dysfunction and Benign Prostatic Hyperplasia (ED/BPH) is 5 mg orally once daily without regard to timing of sexual activity. Take at approximately the same time daily.
Table 1 for CHEWTADZY recommended dose administered orally for erectile dysfunction (ED) in patients with renal impairment [see WARNINGS AND PRECAUTIONS and Use In Specific Populations].
Table 1: CHEWTADZY Recommended Dose for ED in Patients with Renal Impairment
| Estimated Creatinine Clearance (CrCl) | Starting Dose | Maximum Dose |
| Greater than 50 mL/min | 10 mg* (not more than once per day) | 20 mg (not more than once per day) |
| 30 to 50 mL/min | 5 mg (not more than once per day) | 10 mg (not more than once per 48 hours) |
| Less than 30 mL/min or hemodialysis | 5 mg (not more than once per 72 hours) | 5 mg (not more than once per 72 hours) |
| *If needed, starting dose of 10 mg can be decreased to 5 mg | ||
See Table 2 for CHEWTADZY oral recommended dosages administered orally for once daily use for BPH and ED/BPH in patients with renal impairment [see WARNINGS AND PRECAUTIONS and Use In Specific Populations].
Table 2: CHEWTADZY Recommended Dosage for Once Daily for BPH and ED/BPH in Patients withRenal Impairment
| Estimated Creatinine Clearance (CrCl) | Starting Dose | Maximum Dose |
| Greater than 50 mL/min | 5 mg (Once daily) | 5 mg (Once daily) |
| 30 to 50 mL/min or less or hemodialysis | Use Not Recommended | |
See Table 3 for the oral recommended dose administered orally for use as needed for ED in patients with hepatic impairment [see WARNINGS AND PRECAUTIONS and Use In Specific Populations].
Table 3: CHEWTADZY Recommended Dosage for Use as Needed for Erectile Dysfunction in Patients with Hepatic Impairment
| Hepatic Impairment Classification | Starting Dose | Maximum Dose |
| Child-Pugh Class A (Mild hepatic impairment) Child-Pugh Class B (Moderate hepatic impairment) | 10 mg* (not more than once per day) | 10 mg (not more than once per day) |
| Child-Pugh Class C (Severe hepatic impairment) | Use Not Recommended | |
| *If needed, starting dose of 10 mg can be decreased to 5 mg | ||
Concomitant use of nitrates in any form is contraindicated [see CONTRAINDICATIONS].
ED
When CHEWTADZY is co-administered with an alpha-blocker in patients being treated for ED, patients should be stable on alpha-blocker therapy prior to initiating treatment. Initiate CHEWTADZY at the lowest recommended dosage [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
BPH
CHEWTADZY is not recommended for use in combination with alpha-blockers for the treatment of BPH [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
CHEWTADZY For Use as Needed
For patients taking concomitant strong inhibitors of CYP3A4, such as ketoconazole or ritonavir, the maximum recommended dosage of CHEWTADZY is 10 mg, not to exceed once every 72 hours [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS].
CHEWTADZY For Once Daily Use
CHEWTADZY is not recommended for patients taking concomitant strong inhibitors of CYP3A4, such as ketoconazole or ritonavir [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS].
CHEWTADZY (tadalafil) is supplied as follows: Three strengths of round-shaped blue colored (mottled), biconvex, uncoated chewable tablets are supplied in the following package sizes:
5 mg chewable tablets debossed with “N627” on one side and plain on the other side
Child-resistant closure bottles of 1000 chewable tablets NDC 70954-627-10
10 mg chewable tablets debossed with “N628” on one side and plain on the other side Child-resistant closure bottles of 750 chewable tablets NDC 70954-628-10
20 mg chewable tablets debossed with “N629” on one side and plain on the other side Child-resistant closure bottles of 500 chewable tablets NDC 70954-629-10
Store at 20°C to 25°C (69°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F) [see USP Controlled Room Temperature]. Keep out of reach of children.
Distributed by: ANI Pharmaceuticals, Inc.Baudette, MN 56623. Revised: Jun 2024
The following clinically significant adverse reactions are described elsewhere in the labeling:
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Tadalafil was administered to over 9000 men during clinical trials worldwide. In trials of tadalafil for once daily use, a total of 1434, 905, and 115 were treated for at least 6 months, 1 year, and 2 years, respectively. For tadalafil for use as needed, over 1300 and 1000 subjects were treated for at least 6 months and 1 year, respectively.
In eight primary placebo-controlled clinical studies of 12 weeks duration, mean age was 59 years (range 22 to 88) and the discontinuation rate due to adverse reactions in patients treated with tadalafil 10 or 20 mg was 3.1%, compared to 1.4% in placebo treated patients.
When taken as recommended in the placebo-controlled clinical trials, the following adverse reactions were reported (see Table 4) for tadalafil for use as needed:
Table 4: Treatment-Emergent Adverse Reactions Reported by ≥2% of Patients Treated with Tadalafil (10 or 20 mg) and More Frequent on Drug than Placebo in the Eight Primary Placebo-Controlled Clinical Studies (Including a Study in Patients with Diabetes) for Tadalafil for Use as Needed for ED
| Adverse Reaction | Placebo (N=476) |
Tadalafil 5 mg (N=151) |
Tadalafil 10 mg (N=394) |
Tadalafil 20 mg (N=635) |
| Headache | 5% | 11% | 11% | 15% |
| Dyspepsia | 1% | 4% | 8% | 10% |
| Back pain | 3% | 3% | 5% | 6% |
| Myalgia | 1% | 1% | 4% | 3% |
| Nasal congestion | 1% | 2% | 3% | 3% |
| Flushinga | 1% | 2% | 3% | 3% |
| Pain in limb | 1% | 1% | 3% | 3% |
| a The term flushing includes: facial flushing and flushing | ||||
In three placebo-controlled clinical trials of 12 weeks duration, two in patients with BPH and one in patients with ED and BPH, the mean age was 63 years (range 44 to 93) and the discontinuation rate due to adverse reactions in patients treated with tadalafil was 3.6% compared to 1.6% in placebo-treated patients. Adverse reactions leading to discontinuation reported by at least 2 patients treated with tadalafil included headache, upper abdominal pain, and myalgia. The following adverse reactions were reported (see Table 5).
Table 5: Treatment-Emergent Adverse Reactions Reported by ≥1% of Patients Treated with Tadalafil for Once Daily Use (5 mg) and More Frequent on Drug than Placebo in Three Placebo-Controlled ClinicalStudies of 12 Weeks Treatment Duration, including Two Studies for Tadalafil for Once Daily Use for BPH and One Study for ED and BPH
| Adverse Reaction | Placebo (N=576) |
Tadalafil 5 mg (N=581) |
| Headache | 2.3% | 4.1% |
| Dyspepsia | 0.2% | 2.4% |
| Back pain | 1.4% | 2.4% |
| Nasopharyngitis | 1.6% | 2.1% |
| Diarrhea | 1.0% | 1.4% |
| Pain in extremity | 0.0% | 1.4% |
| Myalgia | 0.3% | 1.2% |
| Dizziness | 0.5% | 1.0% |
Additional, less frequent adverse reactions (<1%) reported in the controlled clinical trials of tadalafil for BPH or ED and BPH included: gastroesophageal reflux disease, upper abdominal pain, nausea, vomiting, arthralgia, and muscle spasm.
Back pain or myalgia was reported at incidence rates described in Tables 4 and 5. In tadalafil clinical pharmacology trials, back pain or myalgia generally occurred 12 to 24 hours after dosing and typically resolved within 48 hours. The back pain/myalgia associated with tadalafil treatment was characterized by diffuse bilateral lower lumbar, gluteal, thigh, or thoracolumbar muscular discomfort and was exacerbated by recumbency. In general, pain was reported as mild or moderate in severity and resolved without medical treatment, but severe back pain was reported with a low frequency (<5% of all reports). When medical treatment was necessary, acetaminophen or non-steroidal anti-inflammatory drugs were generally effective; however, in a small percentage of subjects who required treatment, a mild narcotic (e.g., codeine) was used. Overall, approximately 0.5% of all subjects treated with tadalafil for on demand use discontinued treatment as a consequence of back pain/myalgia. In the 1-year open label extension study, back pain and myalgia were reported in 5.5% and 1.3% of patients, respectively. Diagnostic testing, including measures for inflammation, muscle injury, or renal damage revealed no evidence of medically significant underlying pathology. Incidence rates for tadalafil for once daily use for ED, BPH and BPH/ED are described in Table 2. In studies of tadalafil for once daily use, adverse reactions of back pain and myalgia were generally mild or moderate with a discontinuation rate of <1% across all indications.
Across placebo-controlled studies with tadalafil for use as needed for ED, diarrhea was reported more frequently in patients 65 years of age and older who were treated with tadalafil (2.5% of patients) [see Use In Specific Populations].
Across all studies with any tadalafil dose, reports of changes in color vision were rare (<0.1% of patients).
The following section identifies additional, less frequent events (<2%) reported in controlled clinical trials of tadalafil for once daily use or use as needed. A causal relationship of these events to tadalafil is uncertain. Excluded from this list are those events that were minor, those with no plausible relation to drug use, and reports too imprecise to be meaningful:
Body as a Whole - asthenia, face edema, fatigue, pain, peripheral edema
Cardiovascular - angina pectoris, chest pain, hypotension, myocardial infarction, postural hypotension, palpitations, syncope, tachycardia
Digestive - abnormal liver function tests, dry mouth, dysphagia, esophagitis, gastritis, GGTP increased, loose stools, nausea, upper abdominal pain, vomiting, gastroesophageal reflux disease, hemorrhoidal hemorrhage, rectal hemorrhage
Musculoskeletal - arthralgia, neck pain
Nervous - dizziness, hypesthesia, insomnia, paresthesia, somnolence, vertigo
Renal and Urinary - renal impairment
Respiratory - dyspnea, epistaxis, pharyngitis
Skin and Appendages - pruritus, rash, sweating
Ophthalmologic - blurred vision, changes in color vision, conjunctivitis (including conjunctival hyperemia), eye pain, lacrimation increase, swelling of eyelids
Otologic - sudden decrease or loss of hearing, tinnitus
Urogenital - erection increased, spontaneous penile erection
The following adverse reactions have been identified during post approval use of tadalafil. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These events have been chosen for inclusion either due to their seriousness, reporting frequency, lack of clear alternative causation, or a combination of these factors.
Serious cardiovascular events, including myocardial infarction, sudden cardiac death, stroke, chest pain, palpitations, and tachycardia, have been reported postmarketing in temporal association with the use of tadalafil. Most, but not all, of these patients had preexisting cardiovascular risk factors. Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of tadalafil without sexual activity. Others were reported to have occurred hours to days after the use of tadalafil and sexual activity. It is not possible to determine whether these events are related directly to tadalafil, to sexual activity, to the patient’s underlying cardiovascular disease, to a combination of these factors, or to other factors [see WARNINGS AND PRECAUTIONS].
Body as a Whole - hypersensitivity reactions including urticaria, Stevens-Johnson syndrome, and exfoliative dermatitis
Nervous - migraine, seizure and seizure recurrence, transient global amnesia
Ophthalmologic - visual field defect, retinal vein occlusion, retinal artery occlusion
Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely postmarketing in temporal association with the use of PDE5 inhibitors, including tadalafil. Most, but not all, of these patients had underlying anatomic or vascular risk factors for development of NAION, including but not necessarily limited to: low cup to disc ratio (“crowded disc”), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia, and smoking [see WARNINGS AND PRECAUTIONS].
Otologic - Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including tadalafil. In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of tadalafil, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors [see WARNINGS AND PRECAUTIONS].
Urogenital - priapism [see WARNINGS AND PRECAUTIONS].
Administration of CHEWTADZY to patients who are using any form of organic nitrate, is contraindicated. In clinical pharmacology studies, tadalafil was shown to potentiate the hypotensive effect of nitrates. In a patient who has taken tadalafil, where nitrate administration is deemed medically necessary in a life-threatening situation, at least 48 hours should elapse after the last dose of CHEWTADZY before nitrate administration is considered. In such circumstances, nitrates should still only be administered under close medical supervision with appropriate hemodynamic monitoring [see DOSAGE AND ADMINISTRATION, CONTRAINDICATIONS, and CLINICAL PHARMACOLOGY].
Caution is advised when PDE5 inhibitors are coadministered with alpha-blockers. PDE5 inhibitors, including CHEWTADZY, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated. Clinical pharmacology studies have been conducted with coadministration of tadalafil with doxazosin, tamsulosin or alfuzosin [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS, and CLINICAL PHARMACOLOGY].
PDE5 inhibitors, including tadalafil, are mild systemic vasodilators. Clinical pharmacology studies were conducted to assess the effect of tadalafil on the potentiation of the blood-pressure-lowering effects of selected antihypertensive medications (amlodipine, angiotensin II receptor blockers, bendrofluazide, enalapril, and metoprolol). Small reductions in blood pressure occurred following coadministration of tadalafil with these agents compared with placebo [see WARNINGS AND PRECAUTIONS and CLINICAL PHARMACOLOGY].
Both alcohol and tadalafil, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure-lowering effects of each individual compound may be increased. Substantial consumption of alcohol (e.g., 5 units or greater) in combination with CHEWTADZY can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache. Tadalafil did not affect alcohol plasma concentrations and alcohol did not affect tadalafil plasma concentrations [see WARNINGS AND PRECAUTIONS and CLINICAL PHARMACOLOGY].
[See DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS].
Simultaneous administration of an antacid (magnesium hydroxide/aluminum hydroxide) and tadalafil reduced the apparent rate of absorption of tadalafil without altering exposure (AUC) to tadalafil.
An increase in gastric pH resulting from administration of nizatidine had no significant effect on tadalafil pharmacokinetics.
CHEWTADZY is a substrate of and predominantly metabolized by CYP3A4. Studies have shown that drugs that inhibit CYP3A4 can increase tadalafil exposure.
CYP3A4 (e.g., Ketoconazole)
Ketoconazole (400 mg daily), a selective and potent inhibitor of CYP3A4, increased tadalafil 20 mg single-dose exposure (AUC) by 312% and Cmax by 22%, relative to the values for tadalafil 20 mg alone. Ketoconazole (200 mg daily) increased tadalafil 10-mg single-dose exposure (AUC) by 107% and Cmax by 15%, relative to the values for tadalafil 10 mg alone [see DOSAGE AND ADMINISTRATION].
Although specific interactions have not been studied, other CYP3A4 inhibitors, such as erythromycin, itraconazole, and grapefruit juice, would likely increase tadalafil exposure.
HIV Protease Inhibitor
Ritonavir (500 mg or 600 mg twice daily at steady state), an inhibitor of CYP3A4, CYP2C9, CYP2C19, and CYP2D6, increased tadalafil 20-mg single-dose exposure (AUC) by 32% with a 30% reduction in Cmax, relative to the values for tadalafil 20 mg alone. Ritonavir (200 mg twice daily), increased tadalafil 20-mg single-dose exposure (AUC) by 124% with no change in Cmax, relative to the values for tadalafil 20 mg alone. Although specific interactions have not been studied, other HIV protease inhibitors would likely increase tadalafil exposure [see DOSAGE AND ADMINISTRATION].
Studies have shown that drugs that induce CYP3A4 can decrease tadalafil exposure.
CYP3A4 (e.g., Rifampin)
Rifampin (600 mg daily), a CYP3A4 inducer, reduced tadalafil 10-mg single-dose exposure (AUC) by 88% and Cmax by 46%, relative to the values for tadalafil 10 mg alone. Although specific interactions have not been studied, other CYP3A4 inducers, such as carbamazepine, phenytoin, and phenobarbital, would likely decrease tadalafil exposure. No dose adjustment is warranted. The reduced exposure of tadalafil with the coadministration of rifampin or other CYP3A4 inducers can be anticipated to decrease the efficacy of CHEWTADZY for once daily use; the magnitude of decreased efficacy is unknown.
Tadalafil did not potentiate the increase in bleeding time caused by aspirin.
CHEWTADZY is not expected to cause clinically significant inhibition or induction of the clearance of drugs metabolized by cytochrome P450 (CYP) isoforms. Studies have shown that tadalafil does not inhibit or induce P450 isoforms CYP1A2, CYP3A4, CYP2C9, CYP2C19, CYP2D6, and CYP2E1.
CYP1A2 (e.g. Theophylline)
Tadalafil had no significant effect on the pharmacokinetics of theophylline. When tadalafil was administered to subjects taking theophylline, a small augmentation (3 beats per minute) of the increase in heart rate associated with theophylline was observed.
CYP2C9 (e.g. Warfarin)
Tadalafil had no significant effect on exposure (AUC) to S-warfarin or R-warfarin, nor did tadalafil affect changes in prothrombin time induced by warfarin.
CYP3A4 (e.g. Midazolam or Lovastatin)
Tadalafil had no significant effect on exposure (AUC) to midazolam or lovastatin.
Coadministration of tadalafil (40 mg once per day) for 10 days did not have a significant effect on the steady-state pharmacokinetics of digoxin (0.25 mg/day) in healthy subjects.
Included as part of the PRECAUTIONS section.
Evaluation of erectile dysfunction and BPH should include an appropriate medical assessment to identify potential underlying causes, as well as treatment options.
Before prescribing CHEWTADZY, it is important to note the following:
Consider the cardiovascular status of patients, since there is a degree of cardiac risk associated with sexual activity. Therefore, treatments for erectile dysfunction, including CHEWTADZY, should not be used in men for whom sexual activity is inadvisable as a result of their underlying cardiovascular status.
Patients who experience symptoms upon initiation of sexual activity should be advised to refrain from further sexual activity and seek immediate medical attention.
Discuss with patients the appropriate action in the event that they experience anginal chest pain requiring nitroglycerin following intake of CHEWTADZY. In such a patient, who has taken CHEWTADZY, where nitrate administration is deemed medically necessary for a life-threatening situation, at least 48 hours should have elapsed after the last dose of CHEWTADZY before nitrate administration is considered. In such circumstances, nitrates should still only be administered under close medical supervision with appropriate hemodynamic monitoring. Therefore, patients who experience anginal chest pain after taking CHEWTADZY should seek immediate medical attention [see CONTRAINDICATIONS].
Patients with left ventricular outflow obstruction, (e.g., aortic stenosis and idiopathic hypertrophic subaortic stenosis) can be sensitive to the action of vasodilators, including PDE5 inhibitors.
The following groups of patients with cardiovascular disease were not included in clinical safety and efficacy trials for tadalafil, and therefore until further information is available, CHEWTADZY is not recommended for the following groups of patients:
As with other PDE5 inhibitors, tadalafil has mild systemic vasodilatory properties that may result in transient decreases in blood pressure. In a clinical pharmacology study, tadalafil 20 mg resulted in a mean maximal decrease in supine blood pressure, relative to placebo, of 1.6/0.8 mm Hg in healthy subjects [see CLINICAL PHARMACOLOGY]. While this effect should not be of consequence in most patients, prior to prescribing CHEWTADZY, physicians should carefully consider whether their patients with underlying cardiovascular disease could be affected adversely by such vasodilatory effects. Patients with severely impaired autonomic control of blood pressure may be particularly sensitive to the actions of vasodilators, including PDE5 inhibitors.
CHEWTADZY for once daily use provides continuous plasma tadalafil levels. Consider this when evaluating the potential for interactions with medications (e.g., nitrates, alpha-blockers, anti-hypertensives and potent inhibitors of CYP3A4) and with substantial consumption of alcohol [see DRUG INTERACTIONS].
Instruct patients who have an erection lasting greater than 4 hours, whether painful or not, to seek emergency medical attention.
Use CHEWTADZY with caution in patients who have conditions that might predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia), or in patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease).
There have been rare reports of prolonged erections greater than 4 hours and priapism (painful erections greater than 6 hours in duration) for this class of compounds. Priapism, if not treated promptly, can result in irreversible damage to the erectile tissue.
Advise patients to stop use of all phosphodiesterase type 5 (PDE5) inhibitors, including CHEWTADZY, and seek medical attention in the event of a sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a rare condition and a cause of decreased vision, including permanent loss of vision, that has been reported rarely postmarketing in temporal association with the use of all PDE5 inhibitors. Based on published literature, the annual incidence of NAION is 2.5-11.8 cases per 100,000 in males aged 50 years and older.
An observational case-crossover study evaluated the risk of NAION when PDE5 inhibitor use, as a class, occurred immediately before NAION onset (within 5 half-lives), compared to PDE5 inhibitor use in a prior time period. The results suggest an approximate 2-fold increase in the risk of NAION, with a risk estimate of 2.15 (95% CI 1.06, 4.34). A similar study reported a consistent result, with a risk estimate of 2.27 (95% CI 0.99, 5.20). Other risk factors for NAION, such as the presence of “crowded” optic disc, may have contributed to the occurrence of NAION in these studies.
Neither the rare postmarketing reports, nor the association of PDE5 inhibitor use and NAION in the observational studies, substantiate a causal relationship between PDE5 inhibitor use and NAION [see ADVERSE REACTIONS].
Consider whether patients with underlying NAION risk factors could be adversely affected by use of PDE5 inhibitors. Individuals who have already experienced NAION are at increased risk of NAION recurrence. Therefore, use PDE5 inhibitors, including CHEWTADZY, with caution in these patients and only when the anticipated benefits outweigh the risks. Individuals with “crowded” optic disc are also considered at greater risk for NAION compared to the general population; however, evidence is insufficient to support screening of prospective users of PDE5 inhibitors, including CHEWTADZY, for this uncommon condition.
Patients with known hereditary degenerative retinal disorders, including retinitis pigmentosa, were not included in the clinical trials, and use of CHEWTADZY in these patients is not recommended.
Advise patients to stop taking CHEWTADZY and seek prompt medical attention in the event of sudden decrease or loss of hearing. These events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to the intake of PDE5 inhibitors, including tadalafil. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors, such as CHEWTADZY, or to other factors [see ADVERSE REACTIONS].
Discuss with patients the potential for CHEWTADZY to augment the blood-pressure-lowering effect of alpha-blockers and antihypertensive medications [see DRUG INTERACTIONS and CLINICAL PHARMACOLOGY].
Caution is advised when PDE5 inhibitors are coadministered with alpha-blockers. PDE5 inhibitors, including CHEWTADZY, and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated. In some patients, concomitant use of these two drug classes can lower blood pressure significantly [see DRUG INTERACTIONS and CLINICAL PHARMACOLOGY], which may lead to symptomatic hypotension (e.g., fainting). Consideration should be given to the following:
Safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other antihypertensive drugs [see DOSAGE AND ADMINISTRATION and DRUG INTERACTIONS].
Inform patients that both alcohol and CHEWTADZY, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure-lowering effects of each individual compound may be increased. Inform patients that substantial consumption of alcohol (e.g., 5 units or greater) in combination with CHEWTADZY can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache [see CLINICAL PHARMACOLOGY].
CHEWTADZY is metabolized predominantly by CYP3A4 in the liver. The dose of CHEWTADZY for use as needed should be limited to 10 mg no more than once every 72 hours in patients taking potent inhibitors of CYP3A4 such as ritonavir, ketoconazole, and itraconazole [see DRUG INTERACTIONS]. CHEWTADZY is not recommended in patients taking potent inhibitors of CYP3A4 due to the lack of a 2.5 mg strength [see DOSAGE AND ADMINISTRATION].
The safety and efficacy of combinations of tadalafil and other PDE5 inhibitors or treatments for erectile dysfunction have not been studied. Inform patients not to take CHEWTADZY with other PDE5 inhibitors, including ADCIRCA.
Studies in vitro have demonstrated that tadalafil is a selective inhibitor of PDE5. PDE5 is found in platelets. When administered in combination with aspirin, tadalafil 20 mg did not prolong bleeding time, relative to aspirin alone. Tadalafil has not been administered to patients with bleeding disorders or significant active peptic ulceration. Although tadalafil has not been shown to increase bleeding times in healthy subjects, use in patients with bleeding disorders or significant active peptic ulceration should be based upon a careful risk-benefit assessment and caution.
The use of CHEWTADZY offers no protection against sexually transmitted diseases. Counseling patients about the protective measures necessary to guard against sexually transmitted diseases, including Human Immunodeficiency Virus (HIV) should be considered.
Prior to initiating treatment with CHEWTADZY for BPH, consider whether patients have other urological conditions that may cause similar symptoms. In addition, prostate cancer and BPH may coexist.
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION)
Physicians should discuss with patients the contraindication of CHEWTADZY with regular and/or intermittent use of organic nitrates. Patients should be counseled that concomitant use of CHEWTADZY with nitrates could cause blood pressure to suddenly drop to an unsafe level, resulting in dizziness, syncope, or even heart attack or stroke.
Physicians should discuss with patients the appropriate action in the event that they experience anginal chest pain requiring nitroglycerin following intake of CHEWTADZY. In such a patient, who has taken CHEWTADZY, where nitrate administration is deemed medically necessary for a life-threatening situation, at least 48 hours should have elapsed after the last dose of CHEWTADZY before nitrate administration is considered. In such circumstances, nitrates should still only be administered under close medical supervision with appropriate hemodynamic monitoring.
Therefore, patients who experience anginal chest pain after taking CHEWTADZY should seek immediate medical attention [see CONTRAINDICATIONS and WARNINGS AND PRECAUTIONS].
Physicians should discuss with patients the contraindication of CHEWTADZY with any use of a GC stimulator, such as riociguat, for pulmonary arterial hypertension. Patients should be counseled that the concomitant use of CHEWTADZY with GC stimulators may cause blood pressure to drop to an unsafe level [see CONTRAINDICATIONS].
Physicians should consider the potential cardiac risk of sexual activity in patients with preexisting cardiovascular disease. Physicians should advise patients who experience symptoms upon initiation of sexual activity to refrain from further sexual activity and seek immediate medical attention [see WARNINGS AND PRECAUTIONS].
Physicians should discuss with patients the potential for CHEWTADZY to augment the blood-pressureÂlowering effect of alpha-blockers, and antihypertensive medications [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
Physicians should discuss with patients the clinical implications of continuous exposure to tadalafil when prescribing CHEWTADZY for once daily use, especially the potential for interactions with medications (e.g., nitrates, alpha-blockers, antihypertensives and potent inhibitors of cytochrome P450 3A4) and with substantial consumption of alcohol [see DOSAGE AND ADMINISTRATION, WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS, CLINICAL PHARMACOLOGY, and Clinical Studies].
There have been rare reports of prolonged erections greater than 4 hours and priapism (painful erections greater than 6 hours in duration) for this class of compounds. Priapism, if not treated promptly, can result in irreversible damage to the erectile tissue. Physicians should advise patients who have an erection lasting greater than 4 hours, whether painful or not, to seek emergency medical attention.
Physicians should advise patients to stop use of all PDE5 inhibitors, including CHEWTADZY, and seek medical attention in the event of a sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision, including possible permanent loss of vision, that has been reported rarely postmarketing in temporal association with the use of all PDE5 inhibitors.
Physicians should discuss with patients the increased risk of NAION in individuals who have already experienced NAION in one eye. Physicians should also discuss with patients the increased risk of NAION among the general population in patients with a “crowded” optic disc, although evidence is insufficient to support screening of prospective users of PDE5 inhibitors, including CHEWTADZY, for this uncommon condition [see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS].
Physicians should advise patients to stop taking PDE5 inhibitors, including CHEWTADZY, and seek prompt medical attention in the event of sudden decrease or loss of hearing. These events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to the intake of PDE5 inhibitors, including tadalafil. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors [see ADVERSE REACTIONS].
Patients should be made aware that both alcohol and CHEWTADZY, a PDE5 inhibitor, act as mild vasodilators. When mild vasodilators are taken in combination, blood-pressure-lowering effects of each individual compound may be increased. Therefore, physicians should inform patients that substantial consumption of alcohol (e.g., 5 units or greater) in combination with CHEWTADZY can increase the potential for orthostatic signs and symptoms, including increase in heart rate, decrease in standing blood pressure, dizziness, and headache [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
The use of CHEWTADZY offers no protection against sexually transmitted diseases. Counseling of patients about the protective measures necessary to guard against sexually transmitted diseases, including Human Immunodeficiency Virus (HIV) should be considered.
Physicians should instruct patients on the appropriate administration of CHEWTADZY to allow optimal use.
CHEWTADZY is a chewable tablet. These tablets are not scored and are not intended to be split. Patients should be instructed to chew the tablet completely before swallowing.
CHEWTADZY may be taken with or without meals, and with or without water.
For CHEWTADZY for use as needed in men with ED, patients should be instructed to chew one tablet at least 30 minutes before anticipated sexual activity. In most patients, the ability to have sexual intercourse is improved for up to 36 hours.
For CHEWTADZY for once daily use in men with ED/BPH, patients should be instructed to chew one tablet at approximately the same time every day without regard for the timing of sexual activity. Tadalafil is effective at improving erectile function over the course of therapy.
For CHEWTADZY for once daily use in men with BPH, patients should be instructed to chew one tablet at approximately the same time every day.
Tadalafil was not carcinogenic to rats or mice when administered daily for 2 years at doses up to 400 mg/kg/day. Systemic drug exposures, as measured by AUC of unbound tadalafil, were approximately 10-fold for mice, and 14-and 26-fold for male and female rats, respectively, the exposures in human males given Maximum Recommended Human Dose (MRHD) of 20 mg.
Tadalafil was not mutagenic in the in vitro bacterial Ames assays or the forward mutation test in mouse lymphoma cells. Tadalafil was not clastogenic in the in vitro chromosomal aberration test in human lymphocytes or the in vivo rat micronucleus assays.
There were no effects on fertility, reproductive performance or reproductive organ morphology in male or female rats given oral doses of tadalafil up to 400 mg/kg/day, a dose producing AUCs for unbound tadalafil of 14-fold for males or 26-fold for females the exposures observed in human males given the MRHD of 20 mg. In beagle dogs given tadalafil daily for 3 to 12 months, there was treatment-related non-reversible degeneration and atrophy of the seminiferous tubular epithelium in the testes in 20-100% of the dogs that resulted in a decrease in spermatogenesis in 40-75% of the dogs at doses of ≥10 mg/kg/day. Systemic exposure (based on AUC) at no-observed-adverse-effect-level (NOAEL) (10 mg/kg/day) for unbound tadalafil was similar to that expected in humans at the MRHD of 20 mg.
There were no treatment-related testicular findings in rats or mice treated with doses up to 400 mg/kg/day for 2 years.
CHEWTADZY (tadalafil) is not indicated for use in females.
There are no data with the use of tadalafil in pregnant women to inform any drug-associated risks for adverse developmental outcomes. In animal reproduction studies, no adverse developmental effects were observed with oral administration of tadalafil to pregnant rats or mice during organogenesis at exposures up to 11 times the maximum recommended human dose (MRHD) of 20 mg/day (see Data).
Animal Data
Animal reproduction studies showed no evidence of teratogenicity, embryotoxicity, or fetotoxicity when tadalafil was given orally to pregnant rats or mice at exposures up to 11 times the maximum recommended human dose (MRHD) of 20 mg/day during organogenesis. In a prenatal/postnatal developmental study in rats, postnatal pup survival decreased following maternal exposure to tadalafil doses greater than 10 times the MRHD based on AUC. Signs of maternal toxicity occurred at doses greater than 16 times the MRHD based on AUC. Surviving offspring had normal development and reproductive performance.
In another rat prenatal and postnatal development study at doses of 60, 200, and 1000 mg/kg, a reduction in postnatal survival of pups was observed. The no observed effect level (NOEL) for maternal toxicity was 200 mg/kg/day and for developmental toxicity was 30 mg/kg/day. This gives approximately 16 and 10 fold exposure multiples, respectively, of the human AUC for the MRHD of 20 mg.
Tadalafil and/or its metabolites cross the placenta, resulting in fetal exposure in rats.
Risk Summary CHEWTADZY is not indicated for use in females.
There is no information on the presence of tadalafil and/or metabolites in human milk, the effects on the breastfed child, or the effects on milk production. Tadalafil and/or its metabolites are present in the milk of lactating rats at concentrations approximately 2.4-fold greater than found in the plasma.
Based on the data from 3 studies in adult males, tadalafil decreased sperm concentrations in the study of 10 mg tadalafil for 6 months and the study of 20 mg tadalafil for 9 months. This effect was not seen in the study of 20 mg tadalafil taken for 6 months. There was no adverse effect of tadalafil 10 mg or 20 mg on mean concentrations of testosterone, luteinizing hormone or follicle stimulating hormone. The clinical significance of the decreased sperm concentrations in the two studies is unknown. There have been no studies evaluating the effect of tadalafil on fertility in men [see CLINICAL PHARMACOLOGY].
Based on studies in animals, a decrease in spermatogenesis was observed in dogs, but not in rats [see Nonclinical Toxicology].
CHEWTADZY is not indicated for use in pediatric patients. Safety and effectiveness in patients below the age of 18 years have not been established.
A randomized, double-blind, placebo-controlled trial in pediatric patients (7 to 14 years of age) with Duchenne muscular dystrophy, who received tadalafil 0.3 mg/kg, tadalafil 0.6 mg/kg, or placebo daily for 48 weeks failed to demonstrate any benefit of treatment with tadalafil on a range of assessments of muscle strength and performance.
Of the total number of subjects in ED clinical studies of tadalafil, approximately 19 percent were 65 and over, while approximately 2 percent were 75 and over. Of the total number of subjects in BPH clinical studies of tadalafil (including the ED/BPH study), approximately 40 percent were over 65, while approximately 10 percent were 75 and over. In these clinical trials, no overall differences in efficacy or safety were observed between older (>65 and ≥75 years of age) and younger subjects (≤65 years of age). However, in placebo-controlled studies with tadalafil for use as needed for ED, diarrhea was reported more frequently in patients 65 years of age and older who were treated with tadalafil (2.5% of patients) [see ADVERSE REACTIONS]. No dose adjustment is warranted based on age alone. However, a greater sensitivity to medications in some older individuals should be considered [see CLINICAL PHARMACOLOGY].
In clinical pharmacology studies, tadalafil exposure (AUC) in subjects with mild or moderate hepatic impairment (Child-Pugh Class A or B) was comparable to exposure in healthy subjects when a dose of 10 mg was administered. There are no available data for doses higher than 10 mg of tadalafil in patients with hepatic impairment. Insufficient data are available for subjects with severe hepatic impairment (Child-Pugh Class C) [see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS].
In clinical pharmacology studies using single-dose tadalafil (5 to 10 mg), tadalafil exposure (AUC) doubled in subjects with creatinine clearance 30 to 80 mL/min. In subjects with end-stage renal disease on hemodialysis, there was a two-fold increase in Cmax and 2.7-to 4.8-fold increase in AUC following single-dose administration of 10 or 20 mg tadalafil. Exposure to total methylcatechol (unconjugated plus glucuronide) was 2-to 4-fold higher in subjects with renal impairment, compared to those with normal renal function. Hemodialysis (performed between 24 and 30 hours post-dose) contributed negligibly to tadalafil or metabolite elimination. In a clinical pharmacology study (N=28) at a dose of 10 mg, back pain was reported as a limiting adverse event in male patients with creatinine clearance 30 to 50 mL/min. At a dose of 5 mg, the incidence and severity of back pain was not significantly different than in the general population. In patients on hemodialysis taking 10-or 20-mg tadalafil, there were no reported cases of back pain [see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS].
Single doses up to 500 mg have been given to healthy subjects, and multiple daily doses up to 100 mg have been given to patients. Adverse events were similar to those seen at lower doses. In cases of overdose, standard supportive measures should be adopted as required. Hemodialysis contributes negligibly to tadalafil elimination.
CHEWTADZY is contraindicated in:
Penile erection during sexual stimulation is caused by increased penile blood flow resulting from the relaxation of penile arteries and corpus cavernosal smooth muscle. This response is mediated by the release of nitric oxide (NO) from nerve terminals and endothelial cells, which stimulates the synthesis of cGMP in smooth muscle cells. Cyclic GMP causes smooth muscle relaxation and increased blood flow into the corpus cavernosum. The inhibition of phosphodiesterase type 5 (PDE5) enhances erectile function by increasing the amount of cGMP. Tadalafil inhibits PDE5. Because sexual stimulation is required to initiate the local release of nitric oxide, the inhibition of PDE5 by tadalafil has no effect in the absence of sexual stimulation.
The effect of PDE5 inhibition on cGMP concentration in the corpus cavernosum and pulmonary arteries is also observed in the smooth muscle of the prostate, the bladder and their vascular supply. The mechanism for reducing BPH symptoms has not been established.
Studies in vitro have demonstrated that tadalafil is a selective inhibitor of PDE5. PDE5 is found in the smooth muscle of the corpus cavernosum, prostate, and bladder as well as in vascular and visceral smooth muscle, skeletal muscle, urethra, platelets, kidney, lung, cerebellum, heart, liver, testis, seminal vesicle, and pancreas.
In vitro studies have shown that the effect of tadalafil is more potent on PDE5 than on other phosphodiesterases. These studies have shown that tadalafil is >10,000-fold more potent for PDE5 than for PDE1, PDE2, PDE4, and PDE7 enzymes, which are found in the heart, brain, blood vessels, liver, leukocytes, skeletal muscle, and other organs. Tadalafil is >10,000-fold more potent for PDE5 than for PDE3, an enzyme found in the heart and blood vessels. Additionally, tadalafil is 700-fold more potent for PDE5 than for PDE6, which is found in the retina and is responsible for phototransduction. Tadalafil is >9,000-fold more potent for PDE5 than for PDE8, PDE9, and PDE10. Tadalafil is 14-fold more potent for PDE5 than for PDE11A1 and 40Âfold more potent for PDE5 than for PDE11A4, two of the four known forms of PDE11. PDE11 is an enzyme found in human prostate, testes, skeletal muscle and in other tissues (e.g., adrenal cortex). In vitro, tadalafil inhibits human recombinant PDE11A1 and, to a lesser degree, PDE11A4 activities at concentrations within the therapeutic range. The physiological role and clinical consequence of PDE11 inhibition in humans have not been defined.
Tadalafil 20 mg administered to healthy male subjects produced no significant difference compared to placebo in supine systolic and diastolic blood pressure (difference in the mean maximal decrease of 1.6/0.8 mm Hg, respectively) and in standing systolic and diastolic blood pressure (difference in the mean maximal decrease of 0.2/4.6 mm Hg, respectively). In addition, there was no significant effect on heart rate.
In clinical pharmacology studies, tadalafil (5 to 20 mg) was shown to potentiate the hypotensive effect of nitrates. Therefore, the use of CHEWTADZY in patients taking any form of nitrates is contraindicated [see CONTRAINDICATIONS].
A study was conducted to assess the degree of interaction between nitroglycerin and tadalafil, should nitroglycerin be required in an emergency situation after tadalafil was taken. This was a double-blind, placebo-controlled, crossover study in 150 male subjects at least 40 years of age (including subjects with diabetes mellitus and/or controlled hypertension) and receiving daily doses of tadalafil 20 mg or matching placebo for 7 days. Subjects were administered a single dose of 0.4 mg sublingual nitroglycerin (NTG) at pre-specified timepoints, following their last dose of tadalafil (2, 4, 8, 24, 48, 72, and 96 hours after tadalafil). The objective of the study was to determine when, after tadalafil dosing, no apparent blood pressure interaction was observed. In this study, a significant interaction between tadalafil and NTG was observed at each timepoint up to and including 24 hours. At 48 hours, by most hemodynamic measures, the interaction between tadalafil and NTG was not observed, although a few more tadalafil subjects compared to placebo experienced greater blood-pressure lowering at this timepoint. After 48 hours, the interaction was not detectable (see Figure 1).
Figure 1: Mean Maximal Change in Blood Pressure (Tadalafil Minus Placebo, Point Estimate with 90% CI) in Response to Sublingual Nitroglycerin at 2 (Supine Only), 4, 8, 24, 48, 72, and 96 Hours after the Last Dose of Tadalafil 20 mg or Placebo
 |
Therefore, CHEWTADZY administration with nitrates is contraindicated. In a patient who has taken CHEWTADZY, where nitrate administration is deemed medically necessary in a life-threatening situation, at least 48 hours should elapse after the last dose of CHEWTADZY before nitrate administration is considered. In such circumstances, nitrates should still only be administered under close medical supervision with appropriate hemodynamic monitoring [see CONTRAINDICATIONS].
Six randomized, double-blinded, crossover clinical pharmacology studies were conducted to investigate the potential interaction of tadalafil with alpha-blocker agents in healthy male subjects [see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS]. In four studies, a single oral dose of tadalafil was administered to healthy male subjects taking daily (at least 7 days duration) an oral alpha-blocker. In two studies, a daily oral alpha-blocker (at least 7 days duration) was administered to healthy male subjects taking repeated daily doses of tadalafil.
Doxazosin
Three clinical pharmacology studies were conducted with tadalafil and doxazosin, an alpha[1]Âadrenergic blocker.
In the first doxazosin study, a single oral dose of tadalafil 20 mg or placebo was administered in a 2-period, crossover design to healthy subjects taking oral doxazosin 8 mg daily (N=18 subjects). Doxazosin was administered at the same time as tadalafil or placebo after a minimum of seven days of doxazosin dosing (see Table 6 and Figure 2).
Table 6: Doxazosin (8 mg/day) Study 1: Mean Maximal Decrease (95% CI) in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure (mm Hg) | Tadalafil 20 mg |
| Supine | 3.6 (-1.5, 8.8) |
| Standing | 9.8 (4.1, 15.5) |
Figure 2: Doxazosin Study 1: Mean Change from Baseline in Systolic Blood Pressure
 |
Blood pressure was measured manually at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after tadalafil or placebo administration. Outliers were defined as subjects with a standing systolic blood pressure of <85 mm Hg or a decrease from baseline in standing systolic blood pressure of >30 mm Hg at one or more time points. There were nine and three outliers following administration of tadalafil 20 mg and placebo, respectively. Five and two subjects were outliers due to a decrease from baseline in standing systolic BP of >30 mm Hg, while five and one subject were outliers due to standing systolic BP <85 mm Hg following tadalafil and placebo, respectively. Severe adverse events potentially related to blood-pressure effects were assessed. No such events were reported following placebo. Two such events were reported following administration of tadalafil. Vertigo was reported in one subject that began 7 hours after dosing and lasted about 5 days. This subject previously experienced a mild episode of vertigo on doxazosin and placebo. Dizziness was reported in another subject that began 25 minutes after dosing and lasted 1 day. No syncope was reported.
In the second doxazosin study, a single oral dose of tadalafil 20 mg was administered to healthy subjects taking oral doxazosin, either 4 or 8 mg daily. The study (N=72 subjects) was conducted in three parts, each a 3-period crossover.
In part A (N=24), subjects were titrated to doxazosin 4 mg administered daily at 8 a.m. Tadalafil was administered at either 8 a.m., 4 p.m., or 8 p.m. There was no placebo control.
In part B (N=24), subjects were titrated to doxazosin 4 mg administered daily at 8 p.m. Tadalafil was administered at either 8 a.m., 4 p.m., or 8 p.m. There was no placebo control.
In part C (N=24), subjects were titrated to doxazosin 8 mg administered daily at 8 a.m. In this part, tadalafil or placebo were administered at either 8 a.m. or 8 p.m.
The placebo-subtracted mean maximal decreases in systolic blood pressure over a 12-hour period after dosing in the placebo-controlled portion of the study (part C) are shown in Table 7 and Figure 3.
Table 7: Doxazosin (8 mg/day) Study 2 (Part C): Mean Maximal Decrease in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure (mm Hg) | Tadalafil 20 mg at 8 a.m. | Tadalafil 20 mg at 8 p.m. |
| Ambulatory Blood-Pressure Monitoring (ABPM) | 7 | 8 |
Figure 3: Doxazosin Study 2 (Part C): Mean Change from Time-Matched Baseline in Systolic Blood Pressure
 |
Blood pressure was measured by ABPM every 15 to 30 minutes for up to 36 hours after tadalafil or placebo. Subjects were categorized as outliers if one or more systolic blood pressure readings of <85 mm Hg were recorded or one or more decreases in systolic blood pressure of >30 mm Hg from a time-matched baseline occurred during the analysis interval.
Of the 24 subjects in part C, 16 subjects were categorized as outliers following administration of tadalafil and 6 subjects were categorized as outliers following placebo during the 24-hour period after 8 a.m. dosing of tadalafil or placebo. Of these, 5 and 2 were outliers due to systolic BP <85 mm Hg, while 15 and 4 were outliers due to a decrease from baseline in systolic BP of >30 mm Hg following tadalafil and placebo, respectively.
During the 24-hour period after 8 p.m. dosing, 17 subjects were categorized as outliers following administration of tadalafil and 7 subjects following placebo. Of these, 10 and 2 subjects were outliers due to systolic BP <85 mm Hg, while 15 and 5 subjects were outliers due to a decrease from baseline in systolic BP of >30 mm Hg, following tadalafil and placebo, respectively.
Some additional subjects in both the tadalafil and placebo groups were categorized as outliers in the period beyond 24 hours.
Severe adverse events potentially related to blood-pressure effects were assessed. In the study (N=72 subjects), 2 such events were reported following administration of tadalafil (symptomatic hypotension in one subject that began 10 hours after dosing and lasted approximately 1 hour, and dizziness in another subject that began 11 hours after dosing and lasted 2 minutes). No such events were reported following placebo. In the period prior to tadalafil dosing, one severe event (dizziness) was reported in a subject during the doxazosin run-in phase.
In the third doxazosin study, healthy subjects (N=45 treated; 37 completed) received 28 days of once per day dosing of tadalafil 5 mg or placebo in a two-period crossover design. After 7 days, doxazosin was initiated at 1 mg and titrated up to 4 mg daily over the last 21 days of each period (7 days on 1 mg; 7 days of 2 mg; 7 days of 4 mg doxazosin). The results are shown in Table 8.
Table 8: Doxazosin Study 3: Mean Maximal Decrease (95% CI) in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure | Tadalafil 5 mg | |
| Day 1 of 4 mg Doxazosin | Supine | 2.4 (-0.4, 5.2) |
| Standing | -0.5 (-4.0, 3.1) | |
| Day 7 of 4 mg Doxazosin | Supine | 2.8 (-0.1, 5.7) |
| Standing | 1.1 (-2.9, 5.0) | |
Blood pressure was measured manually pre-dose at two time points (-30 and -15 minutes) and then at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12 and 24 hours post dose on the first day of each doxazosin dose, (1 mg, 2 mg, 4 mg), as well as on the seventh day of 4 mg doxazosin administration.
Following the first dose of doxazosin 1 mg, there were no outliers on tadalafil 5 mg and one outlier on placebo due to a decrease from baseline in standing systolic BP of >30 mm Hg.
There were 2 outliers on tadalafil 5 mg and none on placebo following the first dose of doxazosin 2 mg due to a decrease from baseline in standing systolic BP of >30 mm Hg.
There were no outliers on tadalafil 5 mg and two on placebo following the first dose of doxazosin 4 mg due to a decrease from baseline in standing systolic BP of >30 mm Hg. There was one outlier on tadalafil 5 mg and three on placebo following the first dose of doxazosin 4 mg due to standing systolic BP <85 mm Hg. Following the seventh day of doxazosin 4 mg, there were no outliers on tadalafil 5 mg, one subject on placebo had a decrease >30 mm Hg in standing systolic blood pressure, and one subject on placebo had standing systolic blood pressure <85 mm Hg. All adverse events potentially related to blood pressure effects were rated as mild or moderate. There were two episodes of syncope in this study, one subject following a dose of tadalafil 5 mg alone, and another subject following coadministration of tadalafil 5 mg and doxazosin 4 mg.
Tamsulosin
In the first tamsulosin study, a single oral dose of tadalafil 10, 20 mg, or placebo was administered in a 3 period, crossover design to healthy subjects taking 0.4 mg once per day tamsulosin, a selective alpha[1A]-adrenergic blocker (N=18 subjects). Tadalafil or placebo was administered 2 hours after tamsulosin following a minimum of seven days of tamsulosin dosing.
Table 9: Tamsulosin (0.4 mg/day) Study 1: Mean Maximal Decrease (95% CI) in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure (mm Hg) | Tadalafil 10 mg | Tadalafil 20 mg |
| Supine | 3.2 (-2.3, 8.6) | 3.2 (-2.3, 8.7) |
| Standing | 1.7 (-4.7, 8.1) | 2.3 (-4.1, 8.7) |
Blood pressure was measured manually at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours after tadalafil or placebo dosing. There were 2, 2, and 1 outliers (subjects with a decrease from baseline in standing systolic blood pressure of >30 mm Hg at one or more time points) following administration of tadalafil 10 mg, 20 mg, and placebo, respectively. There were no subjects with a standing systolic blood pressure <85 mm Hg. No severe adverse events potentially related to blood-pressure effects were reported. No syncope was reported.
In the second tamsulosin study, healthy subjects (N=39 treated; and 35 completed) received 14 days of once per day dosing of tadalafil 5 mg or placebo in a two-period crossover design. Daily dosing of tamsulosin 0.4 mg was added for the last seven days of each period.
Table 10: Tamsulosin Study 2: Mean Maximal Decrease (95% CI) in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure | Tadalafil 5 mg | |
| Day 1 of 0.4 mg Tamsulosin | Supine | -0.1 (-2.2, 1.9) |
| Standing | 0.9 (-1.4, 3.2) | |
| Day 7 of 0.4 mg Tamsulosin | Supine | 1.2 (-1.2, 3.6) |
| Standing | 1.2 (-1.0, 3.5) | |
Blood pressure was measured manually pre-dose at two time points (-30 and -15 minutes) and then at 1, 2, 3, 4, 5, 6, 7, 8, 10, 12, and 24 hours post dose on the first, sixth and seventh days of tamsulosin administration. There were no outliers (subjects with a decrease from baseline in standing systolic blood pressure of >30 mm Hg at one or more time points). One subject on placebo plus tamsulosin (Day 7) and one subject on tadalafil plus tamsulosin (Day 6) had standing systolic blood pressure <85 mm Hg. No severe adverse events potentially related to blood pressure were reported. No syncope was reported.
Alfuzosin
A single oral dose of tadalafil 20 mg or placebo was administered in a 2-period, crossover design to healthy subjects taking once-daily alfuzosin HCl 10 mg extended-release tablets, an alpha[1]-adrenergic blocker (N=17 completed subjects). Tadalafil or placebo was administered 4 hours after alfuzosin following a minimum of seven days of alfuzosin dosing.
Table 11: Alfuzosin (10 mg/day) Study: Mean Maximal Decrease (95% CI) in Systolic Blood Pressure
| Placebo-subtracted mean maximal decrease in systolic blood pressure (mm Hg) | Tadalafil 20 mg |
| Supine | 2.2 (-0.9,-5.2) |
| Standing | 4.4 (-0.2, 8.9) |
Blood pressure was measured manually at 1, 2, 3, 4, 6, 8, 10, 20, and 24 hours after tadalafil or placebo dosing. There was 1 outlier (subject with a standing systolic blood pressure <85 mm Hg) following administration of tadalafil 20 mg. There were no subjects with a decrease from baseline in standing systolic blood pressure of >30 mm Hg at one or more time points. No severe adverse events potentially related to blood pressure effects were reported. No syncope was reported.
Amlodipine
A study was conducted to assess the interaction of amlodipine (5 mg daily) and tadalafil 10 mg. There was no effect of tadalafil on amlodipine blood levels and no effect of amlodipine on tadalafil blood levels. The mean reduction in supine systolic/diastolic blood pressure due to tadalafil 10 mg in subjects taking amlodipine was 3/2 mm Hg, compared to placebo. In a similar study using tadalafil 20 mg, there were no clinically significant differences between tadalafil and placebo in subjects taking amlodipine.
Angiotensin II Receptor Blockers (with and without other antihypertensives)
A study was conducted to assess the interaction of angiotensin II receptor blockers and tadalafil 20 mg. Subjects in the study were taking any marketed angiotensin II receptor blocker, either alone, as a component of a combination product, or as part of a multiple antihypertensive regimen. Following dosing, ambulatory measurements of blood pressure revealed differences between tadalafil and placebo of 8/4 mm Hg in systolic/diastolic blood pressure.
Bendrofluazide
A study was conducted to assess the interaction of bendrofluazide (2.5 mg daily) and tadalafil 10 mg. Following dosing, the mean reduction in supine systolic/diastolic blood pressure due to tadalafil 10 mg in subjects taking bendrofluazide was 6/4 mm Hg, compared to placebo.
Enalapril
A study was conducted to assess the interaction of enalapril (10 to 20 mg daily) and tadalafil 10 mg. Following dosing, the mean reduction in supine systolic/diastolic blood pressure due to tadalafil 10 mg in subjects taking enalapril was 4/1 mm Hg, compared to placebo.
Metoprolol
A study was conducted to assess the interaction of sustained-release metoprolol (25 to 200 mg daily) and tadalafil 10 mg. Following dosing, the mean reduction in supine systolic/diastolic blood pressure due to tadalafil 10 mg in subjects taking metoprolol was 5/3 mm Hg, compared to placebo.
Alcohol and PDE5 inhibitors, including tadalafil, are mild systemic vasodilators. The interaction of tadalafil with alcohol was evaluated in 3 clinical pharmacology studies. In 2 of these, alcohol was administered at a dose of 0.7 g/kg, which is equivalent to approximately 6 ounces of 80-proof vodka in an 80-kg male, and tadalafil was administered at a dose of 10 mg in one study and 20 mg in another. In both these studies, all patients imbibed the entire alcohol dose within 10 minutes of starting. In one of these two studies, blood alcohol levels of 0.08% were confirmed. In these two studies, more patients had clinically significant decreases in blood pressure on the combination of tadalafil and alcohol as compared to alcohol alone. Some subjects reported postural dizziness, and orthostatic hypotension was observed in some subjects. When tadalafil 20 mg was administered with a lower dose of alcohol (0.6 g/kg, which is equivalent to approximately 4 ounces of 80-proof vodka, administered in less than 10 minutes), orthostatic hypotension was not observed, dizziness occurred with similar frequency to alcohol alone, and the hypotensive effects of alcohol were not potentiated.
Tadalafil did not affect alcohol plasma concentrations and alcohol did not affect tadalafil plasma concentrations.
The effects of tadalafil on cardiac function, hemodynamics, and exercise tolerance were investigated in a single clinical pharmacology study. In this blinded crossover trial, 23 subjects with stable coronary artery disease and evidence of exercise-induced cardiac ischemia were enrolled. The primary endpoint was time to cardiac ischemia. The mean difference in total exercise time was 3 seconds (tadalafil 10 mg minus placebo), which represented no clinically meaningful difference. Further statistical analysis demonstrated that tadalafil was non-inferior to placebo with respect to time to ischemia. Of note, in this study, in some subjects who received tadalafil followed by sublingual nitroglycerin in the post-exercise period, clinically significant reductions in blood pressure were observed, consistent with the augmentation by tadalafil of the blood-pressure-lowering effects of nitrates.
Single oral doses of phosphodiesterase inhibitors have demonstrated transient dose-related impairment of color discrimination (blue/green), using the Farnsworth-Munsell 100-hue test, with peak effects near the time of peak plasma levels. This finding is consistent with the inhibition of PDE6, which is involved in phototransduction in the retina. In a study to assess the effects of a single dose of tadalafil 40 mg on vision (N=59), no effects were observed on visual acuity, intraocular pressure, or pupillometry. Across all clinical studies with tadalafil, reports of changes in color vision were rare (<0.1% of patients).
Three studies were conducted in men to assess the potential effect on sperm characteristics of tadalafil 10 mg  (one 6 month study) and 20 mg (one 6 month and one 9 month study) administered daily. There were no adverse effects on sperm morphology or sperm motility in any of the three studies. In the study of 10 mg tadalafil for 6 months and the study of 20 mg tadalafil for 9 months, results showed a decrease in mean sperm concentrations relative to placebo, although these differences were not clinically meaningful. This effect was not seen in the study of 20 mg tadalafil taken for 6 months. In addition there was no adverse effect on mean concentrations of reproductive hormones, testosterone, luteinizing hormone or follicle stimulating hormone with either 10 or 20 mg of tadalafil compared to placebo.
The effect of a single 100-mg dose of tadalafil on the QT interval was evaluated at the time of peak tadalafil concentration in a randomized, double-blinded, placebo, and active (intravenous ibutilide) -controlled crossover study in 90 healthy males aged 18 to 53 years. The mean change in QTc (Fridericia QT correction) for tadalafil, relative to placebo, was 3.5 milliseconds (two-sided 90% CI=1.9, 5.1). The mean change in QTc (Individual QT correction) for tadalafil, relative to placebo, was 2.8 milliseconds (two-sided 90% CI=1.2, 4.4). A 100-mg dose of tadalafil (5 times the highest recommended dose) was chosen because this dose yields exposures covering those observed upon coadministration of tadalafil with potent CYP3A4 inhibitors or those observed in renal impairment. In this study, the mean increase in heart rate associated with a 100-mg dose of tadalafil compared to placebo was 3.1 beats per minute.
Over a dose range of 2.5 to 20 mg, tadalafil exposure (AUC) increases proportionally with dose in healthy subjects. Steady-state plasma concentrations are attained within 5 days of once per day dosing and exposure is approximately 1.6-fold greater than after a single dose.
After single oral-dose administration of CHEWTADZY under fasting conditions, the maximum observed plasma concentration (Cmax) of tadalafil is achieved between 30 minutes and 4.5 hours (median time of 2.7 hours). The mean (± standard deviation) observed total plasma concentration (AUC0-inf) and Cmax were 16153.1 (±5953.5) hr*ng/mL and 368.7 (±101.5) ng/mL, respectively. Absolute bioavailability of tadalafil following oral dosing has not been determined.
Effect Of Food
No clinically significant differences in tadalafil pharmacokinetics were observed following administration of a high-fat meal in healthy subjects.
Effect Of Water
No clinically significant differences in tadalafil pharmacokinetics were observed following administration of water in healthy subjects.
The mean apparent volume of distribution following oral administration is approximately 63 L, indicating that tadalafil is distributed into tissues. At therapeutic concentrations, 94% of tadalafil in plasma is bound to proteins.
Less than 0.0005% of the administered dose appeared in the semen of healthy subjects.
Metabolism
Tadalafil is predominantly metabolized by CYP3A4 to a catechol metabolite. The catechol metabolite undergoes extensive methylation and glucuronidation to form the methylcatechol and methylcatechol glucuronide conjugate, respectively. The major circulating metabolite is the methylcatechol glucuronide. Methylcatechol concentrations are less than 10% of glucuronide concentrations. In vitro data suggests that metabolites are not expected to be pharmacologically active at observed metabolite concentrations.
Excretion
The mean oral clearance for tadalafil is 2.5 L/hr. The mean terminal half-life after oral administration is 35 hours in healthy subjects receiving CHEWTADZY. Tadalafil is excreted predominantly as metabolites, mainly in the feces (approximately 61% of the dose) and to a lesser extent in the urine (approximately 36% of the dose).
Healthy male elderly subjects (65 years or over) had a lower oral clearance of tadalafil, resulting in 25% higher exposure (AUC) with no effect on Cmax relative to that observed in healthy subjects 19 to 45 years of age. No dose adjustment is warranted based on age alone. However, greater sensitivity to medications in some older individuals should be considered [see Use In Specific Populations].
In male patients with diabetes mellitus after a 10 mg tadalafil dose, exposure (AUC) was reduced approximately 19% and Cmax was 5% lower than that observed in healthy subjects. No dose adjustment is warranted.
In patients with BPH following single and multiple-doses of 20 mg tadalafil, no statistically significant differences in exposure (AUC and Cmax) were observed between elderly (70 to 85 years) and younger (≤60 years of age) subjects. No dose adjustment is warranted.
Animal studies showed vascular inflammation in tadalafil-treated mice, rats, and dogs. In mice and rats, lymphoid necrosis and hemorrhage were seen in the spleen, thymus, and mesenteric lymph nodes at unbound tadalafil exposure of 2-to 33-fold above the human exposure (AUCs) at the MRHD of 20 mg. In dogs, an increased incidence of disseminated arteritis was observed in 1-and 6-month studies at unbound tadalafil exposure of 1-to 54-fold above the human exposure (AUC) at the MRHD of 20 mg. In a 12-month dog study, no disseminated arteritis was observed, but 2 dogs exhibited marked decreases in white blood cells (neutrophils) and moderate decreases in platelets with inflammatory signs at unbound tadalafil exposures of approximately 14-to 18-fold the human exposure at the MRHD of 20 mg. The abnormal blood-cell findings were reversible within 2 weeks after stopping treatment.
The efficacy and safety of tadalafil in the treatment of erectile dysfunction has been evaluated in 22 clinical trials of up to 24-weeks duration, involving over 4000 patients. Tadalafil, when taken as needed up to once per day, was shown to be effective in improving erectile function in men with erectile dysfunction (ED).
Tadalafil was studied in the general ED population in 7 randomized, multicenter, double-blinded, placebo-controlled, parallel-arm design, primary efficacy and safety studies of 12-weeks duration. Two of these studies were conducted in the United States and 5 were conducted in centers outside the US. Additional efficacy and safety studies were performed in ED patients with diabetes mellitus and in patients who developed ED status post bilateral nerve-sparing radical prostatectomy.
In these 7 trials, tadalafil was taken as needed, at doses ranging from 2.5 to 20 mg, up to once per day. Patients were free to choose the time interval between dose administration and the time of sexual attempts. Food and alcohol intake were not restricted.
Several assessment tools were used to evaluate the effect of tadalafil on erectile function. The 3 primary outcome measures were the Erectile Function (EF) domain of the International Index of Erectile Function (IIEF) and Questions 2 and 3 from Sexual Encounter Profile (SEP). The IIEF is a 4-week recall questionnaire that was administered at the end of a treatment-free baseline period and subsequently at follow-up visits after randomization. The IIEF EF domain has a 30-point total score, where higher scores reflect better erectile function. SEP is a diary in which patients recorded each sexual attempt made throughout the study. SEP Question 2 asks, “Were you able to insert your penis into the partner's vagina?” SEP Question 3 asks, “Did your erection last long enough for you to have successful intercourse?” The overall percentage of successful attempts to insert the penis into the vagina (SEP2) and to maintain the erection for successful intercourse (SEP3) is derived for each patient.
The 2 primary US efficacy and safety trials included a total of 402 men with erectile dysfunction, with a mean age of 59 years (range 27 to 87 years). The population was 78% White, 14% Black, 7% Hispanic, and 1% of other ethnicities, and included patients with ED of various severities, etiologies (organic, psychogenic, mixed), and with multiple co-morbid conditions, including diabetes mellitus, hypertension, and other cardiovascular disease. Most (>90%) patients reported ED of at least 1-year duration. Study A was conducted primarily in academic centers. Study B was conducted primarily in community-based urology practices. In each of these 2 trials, tadalafil 20 mg showed clinically meaningful and statistically significant improvements in all 3 primary efficacy variables (see Table 12). The treatment effect of tadalafil did not diminish over time.
Table 12: Mean Endpoint and Change from Baseline for the Primary Efficacy Variables in the TwoPrimary US Trials
| Study A | Study B | |||||
| Placebo (N=49) |
Tadalafil 20 mg (N=146) |
p-value | Placebo (N=48) |
Tadalafil 20 mg (N=159) |
p-value | |
| EF Domain Score | ||||||
| Endpoint | 13.5 | 19.5 | 13.6 | 22.5 | ||
| Change from baseline | -0.2 | 6.9 | <.001 | 0.3 | 9.3 | <.001 |
| Insertion of Penis (SEP2) | ||||||
| Endpoint | 39% | 62% | 43% | 77% | ||
| Change from baseline | 2% | 26% | <.001 | 2% | 32% | <.001 |
| Maintenance of Erection (SEP3) | ||||||
| Endpoint | 25% | 50% | 23% | 64% | ||
| Change from baseline | 5% | 34% | <.001 | 4% | 44% | <.001 |
The 5 primary efficacy and safety studies conducted in the general ED population outside the US included 1112 patients, with a mean age of 59 years (range 21 to 82 years). The population was 76% White, 1% Black, 3% Hispanic, and 20% of other ethnicities, and included patients with ED of various severities, etiologies (organic, psychogenic, mixed), and with multiple co-morbid conditions, including diabetes mellitus, hypertension, and other cardiovascular disease. Most (90%) patients reported ED of at least 1-year duration. In these 5 trials, tadalafil 5, 10, and 20 mg showed clinically meaningful and statistically significant improvements in all 3 primary efficacy variables (see Tables 13, 14 and 15). The treatment effect of tadalafil did not diminish over time.
Table 13: Mean Endpoint and Change from Baseline for the EF Domain of the IIEF in the General ED Population in Five Primary Trials Outside the US
| Placebo | Tadalafil 5 mg | Tadalafil 10 mg | Tadalafil 20 mg | |
| Study C | ||||
| Endpoint [Change from baseline] | 15.0 [0.7] | 17.9 [4.0] | 20.0 [5.6] | |
| p=.006 | p<.001 | |||
| Study D | ||||
| Endpoint [Change from baseline] | 14.4 [1.1] | 17.5 [5.1] | 20.6 [6.0] | |
| p=.002 | p<.001 | |||
| Study E | ||||
| Endpoint [Change from baseline] | 18.1 [2.6] | 22.6 [8.1] | 25.0 [8.0] | |
| p<.001 | p<.001 | |||
| Study Fa | ||||
| Endpoint [Change from baseline] | 12.7 [-1.6] | 22.8 [6.8] | ||
| p<.001 | ||||
| Study G | ||||
| Endpoint [Change from baseline] | 14.5 [-0.9] | 21.2 [6.6] | 23.3 [8.0] | |
| p<.001 | p<.001 | |||
| a Treatment duration in Study F was 6 months | ||||
Table 14: Mean Post-Baseline Success Rate and Change from Baseline for SEP Question 2 (“Were you able to insert your penis into the partner's vagina?”) in the General ED Population in Five Pivotal TrialsOutside the US
| Placebo | Tadalafil 5 mg | Tadalafil 10 mg | Tadalafil 20 mg | |
| Study C | ||||
| Endpoint [Change from baseline] | 49% [6%] | 57% [15%] | 73% [29%] | |
| p=.063 | p<.001 | |||
| Study D | ||||
| Endpoint [Change from baseline] | 46% [2%] | 56% [18%] | 68% [15%] | |
| p=.008 | p<.001 | |||
| Study E | ||||
| Endpoint [Change from baseline] | 55% [10%] | 77% [35%] | 85% [35%] | |
| p<.001 | p<.001 | |||
| Study Fa | ||||
| Endpoint [Change from baseline] | 42% [-8%] | 81% [27%] | ||
| p<.001 | ||||
| Study G | ||||
| Endpoint [Change from baseline] | 45% [-6%] | 73% [21%] | 76% [21%] | |
| p<.001 | p<.001 | |||
| a Treatment duration in Study F was 6 months | ||||
Table 15: Mean Post-Baseline Success Rate and Change from Baseline for SEP Question 3 (“Did yourerection last long enough for you to have successful intercourse?”) in the General ED Population in Five Pivotal Trials Outside the US
| Placebo | Tadalafil 5 mg | Tadalafil 10 mg | Tadalafil 20 mg | |
| Study C | ||||
| Endpoint [Change from baseline] | 26% [4%] | 38% [19%] | 58% [32%] | |
| p=.040 | p<.001 | |||
| Study D | ||||
| Endpoint [Change from baseline] | 28% [4%] | 42% [24%] | 51% [26%] | |
| p<.001 | p<.001 | |||
| Study E | ||||
| Endpoint [Change from baseline] | 43% [15%] | 70% [48%] | 78% [50%] | |
| p<.001 | p<.001 | |||
| Study Fa | ||||
| Endpoint [Change from baseline] | 27% [1%] | 74% [40%] | ||
| p<.001 | ||||
| Study G | ||||
| Endpoint [Change from baseline] | 32% [5%] | 57% [33%] | 62% [29%] | |
| p<.001 | p<.001 | |||
| a Treatment duration in Study F was 6 months | ||||
In addition, there were improvements in EF domain scores, success rates based upon SEP Questions 2 and 3, and patient-reported improvement in erections across patients with ED of all degrees of disease severity while taking tadalafil, compared to patients on placebo.
Therefore, in all 7 primary efficacy and safety studies, tadalafil showed statistically significant improvement in patients' ability to achieve an erection sufficient for vaginal penetration and to maintain the erection long enough for successful intercourse, as measured by the IIEF questionnaire and by SEP diaries.
Tadalafil was shown to be effective in treating ED in patients with diabetes mellitus. Patients with diabetes were included in all 7 primary efficacy studies in the general ED population (N=235) and in one study that specifically assessed tadalafil in ED patients with type 1 or type 2 diabetes (N=216). In this randomized, placebo-controlled, double-blinded, parallel-arm design prospective trial, tadalafil demonstrated clinically meaningful and statistically significant improvement in erectile function, as measured by the EF domain of the IIEF questionnaire and Questions 2 and 3 of the SEP diary (see Table 16).
Table 16: Mean Endpoint and Change from Baseline for the Primary Efficacy Variables in a Study in ED Patients with Diabetes
| Placebo (N=71) |
Tadalafil 10 mg (N=73) |
Tadalafil 20 mg (N=72) |
p-value | |
| EF Domain Score | ||||
| Endpoint [Change from baseline] | 12.2 [0.1] | 19.3 [6.4] | 18.7 [7.3] | <.001 |
| Insertion of Penis (SEP2) | ||||
| Endpoint [Change from baseline] | 30% [-4%] | 57% [22%] | 54% [23%] | <.001 |
| Maintenance of Erection (SEP3) | ||||
| Endpoint [Change from baseline] | 20% [2%] | 48% [28%] | 42% [29%] | <.001 |
Tadalafil was shown to be effective in treating patients who developed ED following bilateral nerve-sparing radical prostatectomy. In 1 randomized, placebo-controlled, double-blinded, parallel-arm design prospective trial in this population (N=303), tadalafil demonstrated clinically meaningful and statistically significant improvement in erectile function, as measured by the EF domain of the IIEF questionnaire and Questions 2 and 3 of the SEP diary (see Table 17).
Table 17: Mean Endpoint and Change from Baseline for the Primary Efficacy Variables in a Study inPatients who Developed ED Following Bilateral Nerve-Sparing Radical Prostatectomy
| Placebo (N=102) |
Tadalafil 20 mg (N=201) |
p-value | |
| EF Domain Score | |||
| Endpoint [Change from baseline] | 13.3 [1.1] | 17.7 [5.3] | <.001 |
| Insertion of Penis (SEP2) | |||
| Endpoint [Change from baseline] | 32% [2%] | 54% [22%] | <.001 |
| Maintenance of Erection (SEP3) | |||
| Endpoint [Change from baseline] | 19% [4%] | 41% [23%] | <.001 |
Several studies were conducted with the objective of determining the optimal use of tadalafil in the treatment of ED. In one of these studies, the percentage of patients reporting successful erections within 30 minutes of dosing was determined. In this randomized, placebo-controlled, double-blinded trial, 223 patients were randomized to placebo, tadalafil 10, or 20 mg. Using a stopwatch, patients recorded the time following dosing at which a successful erection was obtained. A successful erection was defined as at least 1 erection in 4 attempts that led to successful intercourse. At or prior to 30 minutes, 35% (26/74), 38% (28/74), and 52% (39/75) of patients in the placebo, 10-, and 20-mg groups, respectively, reported successful erections as defined above.
Two studies were conducted to assess the efficacy of tadalafil at a given timepoint after dosing, specifically at 24 hours and at 36 hours after dosing.
In the first of these studies, 348 patients with ED were randomized to placebo or tadalafil 20 mg. Patients were encouraged to make 4 total attempts at intercourse; 2 attempts were to occur at 24 hours after dosing and 2 completely separate attempts were to occur at 36 hours after dosing. The results demonstrated a difference between the placebo group and the tadalafil group at each of the pre-specified timepoints. At the 24-hour timepoint, (more specifically, 22 to 26 hours), 53/144 (37%) patients reported at least 1 successful intercourse in the placebo group versus 84/138 (61%) in the tadalafil 20-mg group. At the 36-hour timepoint (more specifically, 33 to 39 hours), 49/133 (37%) of patients reported at least 1 successful intercourse in the placebo group versus 88/137 (64%) in the tadalafil 20-mg group.
In the second of these studies, a total of 483 patients were evenly randomized to 1 of 6 groups: 3 different dosing groups (placebo, tadalafil 10, or 20 mg) that were instructed to attempt intercourse at 2 different times (24 and 36 hours post-dosing). Patients were encouraged to make 4 separate attempts at their assigned dose and assigned timepoint. In this study, the results demonstrated a statistically significant difference between the placebo group and the tadalafil groups at each of the pre-specified timepoints. At the 24-hour timepoint, the mean, per patient percentage of attempts resulting in successful intercourse were 42, 56, and 67% for the placebo, tadalafil 10-, and 20-mg groups, respectively. At the 36-hour timepoint, the mean, per-patient percentage of attempts resulting in successful intercourse were 33, 56, and 62% for placebo, tadalafil 10-, and 20-mg groups, respectively.
The efficacy and safety of tadalafil for once daily use for the treatment of the signs and symptoms of BPH was evaluated in 3 randomized, multinational, double-blinded, placebo-controlled, parallel-design, efficacy and safety studies of 12 weeks duration. Two of these studies were in men with BPH and one study was specific to men with both ED and BPH [see Clinical Studies]. The first study (Study J) randomized 1058 patients to receive either tadalafil 2.5 mg, 5 mg, 10 mg or 20 mg for once daily use or placebo. The second study (Study K) randomized 325 patients to receive either tadalafil 5 mg for once daily use or placebo. The full study population was 87% White, 2% Black, 11% other races; 15% was of Hispanic ethnicity. Patients with multiple co-morbid conditions such as diabetes mellitus, hypertension, and other cardiovascular disease were included.
The primary efficacy endpoint in the two studies that evaluated the effect of tadalafil for the signs and symptoms of BPH was the International Prostate Symptom Score (IPSS), a four week recall questionnaire that was administered at the beginning and end of a placebo run-in period and subsequently at follow-up visits after randomization. The IPSS assesses the severity of irritative (frequency, urgency, nocturia) and obstructive symptoms (incomplete emptying, stopping and starting, weak stream, and pushing or straining), with scores ranging from 0 to 35; higher numeric scores representing greater severity. Maximum urinary flow rate (Qmax), an objective measure of urine flow, was assessed as a secondary efficacy endpoint in Study J and as a safety endpoint in Study K.
The results for BPH patients with moderate to severe symptoms and a mean age of 63.2 years (range 44 to 87) who received either tadalafil 5 mg for once daily use or placebo (N=748) in Studies J and K are shown in Table 18 and Figures 4 and 5, respectively.
In each of these 2 trials, tadalafil 5 mg for once daily use resulted in statistically significant improvement in the total IPSS compared to placebo. Mean total IPSS showed a decrease starting at the first scheduled observation (4 weeks) in Study K and remained decreased through 12 weeks.
Table 18: Mean IPSS Changes in BPH Patients in Two Tadalafil for Once Daily Use Studies
| Study J | Study K | |||||
| Placebo (N=205) |
Tadalafil 5 mg (N=205) |
p-value | Placebo (N=164) |
Tadalafil 5 mg (N=160) |
p-value | |
| Total Symptom Score (IPSS) | ||||||
| Baseline | 17.1 | 17.3 | 16.6 | 17.1 | ||
| Change from Baseline to Week 12 | -2.2 | -4.8 | <.001 | -3.6 | -5.6 | .004 |
Figure 4: Mean IPSS Changes in BPH Patients by Visit in Study J
 |
Figure 5: Mean IPSS Changes in BPH Patients by Visit in Study K
 |
In Study J, the effect of tadalafil 5 mg once daily on maximum urinary flow rate (Qmax) was evaluated as a secondary efficacy endpoint. Mean Qmax increased from baseline in both the treatment and placebo groups (tadalafil 5 mg: 1.6 mL/sec, placebo: 1.2 mL/sec); however, these changes were not significantly different between groups.
In Study K, the effect of tadalafil 5 mg once daily on Qmax was evaluated as a safety endpoint. Mean Qmax increased from baseline in both the treatment and placebo groups (tadalafil 5 mg: 1.6 mL/sec, placebo: 1.1 mL/sec); however, these changes were not significantly different between groups.
Tadalafil for once daily use initiated together with finasteride was shown to be effective in treating the signs and symptoms of BPH in men with an enlarged prostate (>30 cc) for up to 26 weeks. This additional double-blinded, parallel-design study of 26 weeks duration randomized 696 men to initiate either tadalafil 5 mg with finasteride 5 mg or placebo with finasteride 5 mg. The study population had a mean age of 64 years (range 46-86). Patients with multiple co-morbid conditions such as erectile dysfunction, diabetes mellitus, hypertension, and other cardiovascular disease were included.
Tadalafil with finasteride demonstrated statistically significant improvement in the signs and symptoms of BPH compared to placebo with finasteride, as measured by the total IPSS at 12 weeks, the primary study endpoint (see Table 19). Key secondary endpoints demonstrated improvement in total IPSS starting at the first scheduled observation at week 4 (tadalafil -4.0, placebo -2.3: p<.001) and the score remained decreased through 26 weeks (tadalafil -5.5, placebo -4.5; p=.022). However, the magnitude of the treatment difference between placebo/finasteride and tadalafil/finasteride decreased from 1.7 points at Week 4 to 1.0 point at Week 26, as shown in Table 19 and in Figure 6. The incremental benefit of tadalafil beyond 26 weeks is unknown.
Table 19: Mean Total IPSS Changes in BPH Patients in a Tadalafil for Once Daily Use Study Togetherwith Finasteride
| n | Placebo and finasteride 5 mg (N=350)a |
n | Tadalafil 5mg and finasteride 5 mg (N=345)a |
Treatment difference | p- valueb | |
| Total Symptom Score (IPSS) | ||||||
| Baselinec | 349 | 17.4 | 344 | 17.1 | ||
| Change from Baseline to Week 4b | 340 | -2.3 | 330 | -4.0 | -1.7 | <.001 |
| Change from Baseline to Week 12b | 318 | -3.8 | 317 | -5.2 | -1.4 | .001 |
| Change from Baseline to Week 26b | 295 | -4.5 | 308 | -5.5 | -1.0 | .022 |
| a Overall ITT population. b Mixed model for repeated measurements. c Unadjusted mean. |
||||||
Figure 6: Mean Total IPSS Changes By Visit in BPH Patients Taking Tadalafil for Once Daily Use Together With Finasteride
 |
In the 404 patients who had both ED and BPH at baseline, changes in erectile function were assessed as key secondary endpoints using the EF domain of the IIEF questionnaire. Tadalafil with finasteride (N=203) was compared to placebo with finasteride (N=201). A statistically significant improvement from baseline (tadalafil/finasteride 13.7, placebo/finasteride 15.1) was observed at week 4 (tadalafil /finasteride 3.7, placebo/finasteride -1.1; p<.001), week 12 (tadalafil/finasteride 4.7, placebo/finasteride 0.6; p<.001), and week 26 (tadalafil/finasteride 4.7, placebo/finasteride 0.0; p<.001).
The efficacy and safety of tadalafil for once daily use for the treatment of ED, and the signs and symptoms of BPH, in patients with both conditions was evaluated in one placebo-controlled, multinational, double-blind, parallel-arm study which randomized 606 patients to receive either tadalafil 2.5 mg, 5 mg, for once daily use or placebo. ED severity ranged from mild to severe and BPH severity ranged from moderate to severe. The full study population had a mean age of 63 years (range 45 to 83) and was 93% White, 4% Black, 3% other races; 16% were of Hispanic ethnicity. Patients with multiple co-morbid conditions such as diabetes mellitus, hypertension, and other cardiovascular disease were included.
In this study, the co-primary endpoints were total IPSS and the Erectile Function (EF) domain score of the International Index of Erectile Function (IIEF). One of the key secondary endpoints in this study was Question 3 of the Sexual Encounter Profile diary (SEP3). Timing of sexual activity was not restricted relative to when patients took tadalafil.
The efficacy results for patients with both ED and BPH, who received either tadalafil 5 mg for once daily use or placebo (N=408) are shown in Tables 20 and 21 and Figure 7.
Tadalafil 5 mg for once daily use resulted in statistically significant improvements in the total IPSS and in the EF domain of the IIEF questionnaire. Tadalafil 5 mg for once daily use also resulted in statistically significant improvement in SEP3. Tadalafil 2.5 mg did not result in statistically significant improvement in the total IPSS.
Table 20: Mean IPSS and IIEF EF Domain Changes in the Tadalafil 5 mg for Once Daily Use Study in  Patients with ED and BPH
| Placebo | Tadalafil 5 mg | p-value | |
| Total Symptom Score (IPSS) | |||
| (N=193) | (N=206) | ||
| Baseline | 18.2 | 18.5 | |
| Change from Baseline to Week 12 | -3.8 | -6.1 | <.001 |
| EF Domain Score (IIEF EF) | |||
| (N=188) | (N=202) | ||
| Baseline | 15.6 | 16.5 | |
| Endpoint | 17.6 | 22.9 | |
| Change from Baseline to Week 12 | 1.9 | 6.5 | <.001 |
Table 21: Mean SEP Question 3 Changes in the Tadalafil 5 mg for Once Daily Use Study in Patients with ED and BPH
| Placebo (N=187) |
Tadalafil 5 mg (N=199) |
p-value | |
| Maintenance of Erection (SEP3) | |||
| Baseline | 36% | 43% | |
| Endpoint | 48% | 72% | |
| Change from Baseline to Week 12 | 12% | 32% | <.001 |
Tadalafil for once daily use resulted in improvement in the IPSS total score at the first scheduled observation (week 2) and throughout the 12 weeks of treatment (see Figure 7).
Figure 7: Mean IPSS Changes in ED/BPH Patients by Visit in Study L
 |
In this study, the effect of tadalafil 5 mg once daily on Qmax was evaluated as a safety endpoint. Mean Qmax increased from baseline in both the treatment and placebo groups (tadalafil 5 mg: 1.6 mL/sec, placebo: 1.2 mL/sec); however, these changes were not significantly different between groups.
CHEWTADZY™
(Chew-tadzy)
(tadalafil) chewable tablets, for oral use
Read this important information before you start taking CHEWTADZY and each time you get a refill. There may be new information. You may also find it helpful to share this information with your partner. This information does not take the place of talking with your healthcare provider. You and your healthcare provider should talk about CHEWTADZY when you start taking it and at regular checkups. If you do not understand the information, or have questions, talk with your healthcare provider or pharmacist.
What is the most important information I should know about CHEWTADZY?
CHEWTADZY can cause your blood pressure to drop suddenly to an unsafe level if it is taken with certain other medicines. You could get dizzy, faint, or have a heart attack or stroke. Never take CHEWTADZY with any nitrate or guanylate cyclase stimulator medicines.
Do not take CHEWTADZY if you take any medicines called “nitrates.” Nitrates are commonly used to treat angina. Angina is a symptom of heart disease and can cause pain in your chest, jaw, or down your arm.
Do not take CHEWTADZY if you take medicines called guanylate cyclase stimulators which include:
Ask your healthcare provider or pharmacist if you are not sure if any of your medicines are nitrates or guanylate cyclase stimulators, such as riociguat. (See “Who should not take CHEWTADZY?”)
Tell all of your healthcare providers that you take CHEWTADZY. If you need emergency medical care for a heart problem, it will be important for your healthcare provider to know when you last took CHEWTADZY.
After taking a single tablet, some of the active ingredient of CHEWTADZY remains in your body for more than 2 days. The active ingredient can remain longer if you have problems with your kidneys or liver, or you are taking certain other medicines (see “Can other medicines affect CHEWTADZY?”).
Stop sexual activity and get medical help right away if you get symptoms such as chest pain, dizziness, or nausea during sex. Sexual activity can put an extra strain on your heart, especially if your heart is already weak from a heart attack or heart disease.
See also “What are the possible side effects of CHEWTADZY?”
What is CHEWTADZY?
CHEWTADZY is a chewable prescription medicine taken by mouth for the treatment of:
CHEWTADZY for the Treatment of ED
ED is a condition where the penis does not fill with enough blood to harden and expand when a man is sexually excited, or when he cannot keep an erection. A man who has trouble getting or keeping an erection should see his healthcare provider for help if the condition bothers him. CHEWTADZY helps increase blood flow to the penis and may help men with ED get and keep an erection satisfactory for sexual activity. After a man has completed sexual activity, blood flow to his penis decreases, and his erection goes away.
Some form of sexual stimulation is needed for an erection to happen with CHEWTADZY.
CHEWTADZY does not:
CHEWTADZY is only for use as needed in men with ED. CHEWTADZY is not for daily use for the treatment of ED.
CHEWTADZY is only for men over the age of 18, including men with diabetes or who have undergone prostatectomy.
CHEWTADZY for the Treatment of Symptoms of BPH
BPH is a condition that happens in men, where the prostate gland enlarges which can cause urinary symptoms. Men who have symptoms of BPH may take CHEWTADZY one time each day.
CHEWTADZY for the Treatment of ED and Symptoms of BPH
ED and symptoms of BPH may happen in the same person and at the same time. Men who have both ED and symptoms of BPH may take CHEWTADZY one time each day for the treatment of both conditions.
CHEWTADZY is not for women or children.
CHEWTADZY must be used only under a healthcare provider's care.
Who should not take CHEWTADZY?
Do not take CHEWTADZY if you:
Call your healthcare provider or get help right away if you have any of the symptoms of an allergic reaction listed above.
What should I tell my healthcare provider before taking CHEWTADZY?
CHEWTADZY is not right for everyone. Only your healthcare provider and you can decide if CHEWTADZY is right for you. Before taking CHEWTADZY, tell your healthcare provider about all your medical problems, including if you:
Can other medicines affect CHEWTADZY?
Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. CHEWTADZY and other medicines may affect each other. Always check with your healthcare provider before starting or stopping any medicines. Especially tell your healthcare provider if you take any of the following*:
medicines called nitrates (see “What is the most important information I should know about CHEWTADZY?”).
medicines called guanylate cyclase stimulators, such as riociguat (Adempas), used to treat pulmonary hypertension.
How should I take CHEWTADZY?
How should I take CHEWTADZY for symptoms of BPH?
For symptoms of BPH, CHEWTADZY is taken one time each day.
How should I take CHEWTADZY for ED?
For ED, take CHEWTADZY for use as needed:
How should I take CHEWTADZY for both ED and the symptoms of BPH?
For both ED and the symptoms of BPH, CHEWTADZY is taken one time each day.
What should I avoid while taking CHEWTADZY?
What are the possible side effects of CHEWTADZY?
See “What is the most important information I should know about CHEWTADZY?”
The most common side effects of CHEWTADZY include: headache, indigestion, back pain, muscle aches, flushing, stuffy or runny nose and pain in the limb. These side effects usually go away after a few hours. Men who get back pain and muscle aches usually get it 12 to 24 hours after taking CHEWTADZY. Back pain and muscle aches usually go away within 2 days.
Call your healthcare provider if you get any side effect that bothers you or one that does not go away.
Uncommon side effects include: An erection that won't go away (priapism). If you get an erection that lasts more than 4 hours, get medical help right away. Priapism must be treated as soon as possible, or lasting damage can happen to your penis, including the inability to have erections.
Color vision changes, such as seeing a blue tinge (shade) to objects or having difficulty telling the difference between the colors blue and green.
In rare instances, men taking PDE5 inhibitors (oral erectile dysfunction medicines, including CHEWTADZY) reported a sudden decrease or loss of vision in one or both eyes. It is uncertain whether PDE5 inhibitors directly cause the vision loss. If you experience sudden decrease or loss of vision, stop taking PDE5 inhibitors, including CHEWTADZY, and call a healthcare provider right away.
Sudden loss or decrease in hearing, sometimes with ringing in the ears and dizziness, has been rarely reported in people taking PDE5 inhibitors, including CHEWTADZY. It is not possible to determine whether these events are related directly to the PDE5 inhibitors, to other diseases or medicines, to other factors, or to a combination of factors. If you experience these symptoms, stop taking CHEWTADZY and contact a healthcare provider right away.
These are not all the possible side effects of CHEWTADZY.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA1088.
How should I store CHEWTADZY?
Store CHEWTADZY at room temperature between 68°F to 77°F (20°C to 25°C).
Keep CHEWTADZY and all medicines out of the reach of children.
General information about the safe and effective use of CHEWTADZY.
Medicines are sometimes prescribed for purposes other than those listed in a Patient Information leaflet. Do not use CHEWTADZY for a condition for which it was not prescribed. Do not give CHEWTADZY to other people, even if they have the same symptoms that you have. It may harm them.
This is a summary of the most important information about CHEWTADZY. If you would like more information, talk with your healthcare provider. You can ask your healthcare provider or pharmacist for information about CHEWTADZY that is written for health professionals.
For more information you can also visit www.chewtadzy.com or call 1-855-204-1431.
What are the ingredients in CHEWTADZY?
Active Ingredient: tadalafil
Inactive Ingredients: bubblegum flavor (acacia, artificial and natural flavors), colloidal silicon dioxide, croscarmellose sodium, FD&C blue No. 1 aluminum lake, hydroxypropyl cellulose, lactose monohydrate, magnesium stearate, mannitol, microcrystalline cellulose, sodium lauryl sulfate and sucralose
This Patient Information has been approved by the U.S. Food and Drug Administration.
