Enter drug's generic or brand name below. Results will appear here. Note: all drug related information obtained on this page is provided by RX List.
Using the RX LIST database:
(1) Enter the drug name in the search box below and hit ENTER
(2) The rx list web site will open here with the drug search completed. Next, scroll down the page to locate the link to the drug you are searching for and then click on the link.
WARNING
SUICIDAL THOUGHTS AND BEHAVIORS
Antidepressants increased the risk of suicidal thoughts and behavior in children, adolescents, and young adults in short-term studies. These studies did not show an increase in the risk of suicidal thoughts and behavior with antidepressant use in patients over age 24; there was a reduction in risk with antidepressant use in patients aged 65 and older [see WARNINGS AND PRECAUTIONS].
In patients of all ages who are started on antidepressant therapy monitor closely for clinical worsening and emergence of suicidal thoughts and behaviors. Advise families and caregivers of the need for close observation and communication with the prescriber [see WARNINGS AND PRECAUTIONS and PATIENT INFORMATION].
Effexor XR is an extended-release capsule for once-a-day oral administration that contains venlafaxine hydrochloride, a serotonin and norepinephrine reuptake inhibitor (SNRI). Venlafaxine is designated (R/S)-1-[2-(dimethylamino)-1-(4-methoxyphenyl)ethyl] cyclohexanol hydrochloride or (±)-1-[α-[(dimethylamino)methyl]-p-methoxybenzyl] cyclohexanol hydrochloride and has the empirical formula of C17H27NO2 HCl. Its molecular weight is 313.86. The structural formula is shown as follows:
 |
Venlafaxine hydrochloride is a white to off-white crystalline solid, with a solubility of 572 mg/mL in water (adjusted to ionic strength of 0.2 M with sodium chloride). Its octanol:water (0.2 M sodium chloride) partition coefficient is 0.43. Drug release is controlled by diffusion through the coating membrane on the spheroids and is not pH-dependent. Capsules contain venlafaxine hydrochloride equivalent to 37.5 mg, 75 mg, or 150 mg venlafaxine. Inactive ingredients consist of cellulose, ethylcellulose, gelatin, hypromellose, iron oxide, and titanium dioxide.
Effexor XR is indicated in adults for the treatment of:
Administer Effexor XR as a single dose with food, either in the morning or in the evening at approximately the same time each day [see CLINICAL PHARMACOLOGY]. Swallow capsules whole with fluid. Do not divide, crush, chew, or place in water.
The capsule may also be administered by carefully opening the capsule and sprinkling the entire contents on a spoonful of applesauce. This drug/food mixture should be swallowed immediately without chewing and followed with a glass of water to ensure complete swallowing of the pellets (spheroids).
For most patients, the recommended starting dose for Effexor XR is 75 mg per day, administered in a single dose. For some patients, it may be desirable to start at 37.5 mg per day for 4 to 7 days to allow new patients to adjust to the medication before increasing to 75 mg per day. Patients not responding to the initial 75 mg per day dose may benefit from dose increases to a maximum of 225 mg per day. Dose increases should be in increments of up to 75 mg per day, as needed, and should be made at intervals of not less than 4 days. In the clinical studies establishing efficacy, upward titration was permitted at intervals of 2 weeks or more.
For most patients, the recommended starting dose for Effexor XR is 75 mg per day, administered in a single dose. For some patients, it may be desirable to start at 37.5 mg per day for 4 to 7 days to allow new patients to adjust to the medication before increasing to 75 mg per day. Patients not responding to the initial 75 mg per day dose may benefit from dose increases to a maximum of 225 mg per day. Dose increases should be in increments of up to 75 mg per day, as needed, and should be made at intervals of not less than 4 days.
The recommended dose is 75 mg per day, administered in a single dose. There was no evidence that higher doses confer any additional benefit.
The recommended starting dose is 37.5 mg per day of Effexor XR for 7 days. Patients not responding to 75 mg per day may benefit from dose increases to a maximum of approximately 225 mg per day. Dose increases should be in increments of up to 75 mg per day, as needed, and should be made at intervals of not less than 7 days.
Prior to initiating treatment with Effexor XR, screen patients for a personal or family history of bipolar disorder, mania, or hypomania [see WARNINGS AND PRECAUTIONS].
Patients with depression who are currently being treated with Effexor may be switched to Effexor XR at the nearest equivalent dose (mg per day), e.g., 37.5 mg venlafaxine twice a day to 75 mg Effexor XR once daily. However, individual dosage adjustments may be necessary.
Reduce the Effexor XR total daily dose by 50% in patients with mild (Child-Pugh Class A) to moderate (Child-Pugh Class B) hepatic impairment. Reduce the total daily dose by 50% or more in patients with severe hepatic impairment (Child-Pugh Class C) or hepatic cirrhosis [see Use In Specific Populations].
Reduce the Effexor XR total daily dose by 25% to 50% in patients with mild (CLcr 60-89 mL/min) or moderate (CLcr 30-59 mL/min) renal impairment. Reduce the total daily dose by 50% or more in patients undergoing hemodialysis or with severe renal impairment (CLcr < 30 mL/min). Because there was much individual variability in clearance between patients with renal impairment, individualization of dosage is recommended in some patients [see Use In Specific Populations].
A gradual reduction in the dose, rather than abrupt cessation, is recommended when discontinuing therapy with Effexor XR. In clinical studies with Effexor XR, tapering was achieved by reducing the daily dose by 75 mg at one-week intervals. Individualization of tapering may be necessary. In some patients, discontinuation may need to occur over a period of several months [see WARNINGS AND PRECAUTIONS].
At least 14 days must elapse between discontinuation of an MAOI antidepressant and initiation of Effexor XR. In addition, at least 7 days must elapse after stopping Effexor XR before starting an MAOI antidepressant [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS, and DRUG INTERACTIONS].
Effexor XR® is available in the following strengths:
Effexor XR® is available as:
37.5 mg, grey cap/peach body with “W” and “Effexor XR” on the cap and “37.5” on the body.
NDC 58151-125-93, bottle of 30 capsules in unit-of-use package.
NDC 58151-125-77, bottle of 90 capsules in unit-of-use package.
75 mg, peach cap and body with “W” and “Effexor XR” on the cap and “75” on the body.
NDC 58151-126-93, bottle of 30 capsules in unit-of-use package.
NDC 58151-126-77, bottle of 90 capsules in unit-of-use package.
150 mg, dark orange cap and body with “W” and “Effexor XR” on the cap and “150” on the body.
NDC 58151-127-93, bottle of 30 capsules in unit-of-use package.
NDC 58151-127-77, bottle of 90 capsules in unit-of-use package.
Store at controlled room temperature, 20° to 25°C (68° to 77°F).
Distributed by: Viatris Specialty LLC, Morgantown, WV 26505 U.S.A. Revised: Aug 2023
The following adverse reactions are discussed in more detail in other sections of 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 studies of another drug and may not reflect the rates observed in clinical practice.
The most commonly observed adverse reactions in the clinical study database in Effexor XR treated patients in MDD, GAD, SAD, and PD (incidence ≥5% and at least twice the rate of placebo) were: nausea (30.0%), somnolence (15.3%), dry mouth (14.8%), sweating (11.4%), abnormal ejaculation (9.9%), anorexia (9.8%), constipation (9.3%), impotence (5.3%), and decreased libido (5.1%).
Combined across short-term, placebo-controlled premarketing studies for all indications, 12% of the 3,558 patients who received Effexor XR (37.5-225 mg) discontinued treatment due to an adverse experience, compared with 4% of the 2,197 placebo-treated patients in those studies.
The most common adverse reactions leading to discontinuation in ≥1% of the Effexor XR treated patients in the short-term studies (up to 12 weeks) across indications are shown in Table 7.
Table 7: Incidence (%) of Patients Reporting Adverse Reactions Leading to Discontinuation in Placebo-controlled Clinical Studies (up to 12 Weeks Duration)
| Body System Adverse Reaction |
Effexor XR n = 3,558 |
Placebo n = 2,197 |
| Body as a whole | ||
| Asthenia | 1.7 | 0.5 |
| Headache | 1.5 | 0.8 |
| Digestive system | ||
| Nausea | 4.3 | 0.4 |
| Nervous system | ||
| Dizziness | 2.2 | 0.8 |
| Insomnia | 2.1 | 0.6 |
| Somnolence | 1.7 | 0.3 |
| Skin and appendages | 1.5 | 0.6 |
| Sweating | 1.0 | 0.2 |
The number of patients receiving multiple doses of Effexor XR during the premarketing assessment for each approved indication is shown in Table 8. The conditions and duration of exposure to venlafaxine in all development programs varied greatly, and included (in overlapping categories) open and double-blind studies, uncontrolled and controlled studies, inpatient (Effexor only) and outpatient studies, fixed-dose, and titration studies.
Table 8: Patients Receiving Effexor XR in Premarketing Clinical Studies
| Indication | Effexor XR |
| MDD | 705a |
| GAD | 1,381 |
| SAD | 819 |
| PD | 1,314 |
| a In addition, in the premarketing assessment of Effexor, multiple doses were administered to 2,897 patients in studies for MDD. | |
The incidences of common adverse reactions (those that occurred in ≥2% of Effexor XR treated patients [357 MDD patients, 1,381 GAD patients, 819 SAD patients, and 1,001 PD patients] and more frequently than placebo) in Effexor XR treated patients in short-term, placebo-controlled, fixed- and flexible-dose clinical studies (doses 37.5 to 225 mg per day) are shown in Table 9.
The adverse reaction profile did not differ substantially between the different patient populations.
Table 9: Common Adverse Reactions: Percentage of Patients Reporting Adverse Reactions (≥2% and > placebo) in Placebo-controlled Studies (up to 12 Weeks Duration) across All Indications
| Body System Adverse Reaction |
Effexor XR n = 3,558 |
Placebo n = 2,197 |
| Body as a whole | ||
| Asthenia | 12.6 | 7.8 |
| Cardiovascular system | ||
| Hypertension | 3.4 | 2.6 |
| Palpitation | 2.2 | 2.0 |
| Vasodilatation | 3.7 | 1.9 |
| Digestive system | ||
| Anorexia | 9.8 | 2.6 |
| Constipation | 9.3 | 3.4 |
| Diarrhea | 7.7 | 7.2 |
| Dry mouth | 14.8 | 5.3 |
| Nausea | 30.0 | 11.8 |
| Vomiting | 4.3 | 2.7 |
| Nervous system | ||
| Abnormal dreams | 2.9 | 1.4 |
| Dizziness | 15.8 | 9.5 |
| Insomnia | 17.8 | 9.5 |
| Libido decreased | 5.1 | 1.6 |
| Nervousness | 7.1 | 5.0 |
| Paresthesia | 2.4 | 1.4 |
| Somnolence | 15.3 | 7.5 |
| Tremor | 4.7 | 1.6 |
| Respiratory system | ||
| Yawn | 3.7 | 0.2 |
| Skin and appendages | ||
| Sweating (including night sweats) | 11.4 | 2.9 |
| Special senses | ||
| Abnormal vision | 4.2 | 1.6 |
| Urogenital system | ||
| Abnormal ejaculation/orgasm (men)a | 9.9 | 0.5 |
| Anorgasmia (men)a | 3.6 | 0.1 |
| Anorgasmia (women)b | 2.0 | 0.2 |
| Impotence (men)a | 5.3 | 1.0 |
| a Percentages based on the number of men (Effexor XR, n = 1,440; placebo, n = 923) b Percentages based on the number of women (Effexor XR, n = 2,118; placebo, n = 1,274) |
||
Body as a Whole - Photosensitivity reaction, chills
Cardiovascular System - Postural hypotension, syncope, hypotension, tachycardia
Digestive System - Gastrointestinal hemorrhage [see WARNINGS AND PRECAUTIONS], bruxism
Hemic/Lymphatic System - Ecchymosis [see WARNINGS AND PRECAUTIONS]
Metabolic/Nutritional - Hypercholesterolemia, weight gain [see WARNINGS AND PRECAUTIONS], weight loss [see WARNINGS AND PRECAUTIONS]
Nervous System - Seizures [see WARNINGS AND PRECAUTIONS], manic reaction [see WARNINGS AND PRECAUTIONS], agitation, confusion, akathisia, hallucinations, hypertonia, myoclonus, depersonalization, apathy
Skin and Appendages - Urticaria, pruritus, rash, alopecia
Special Senses - Mydriasis, abnormality of accommodation, tinnitus, taste perversion
Urogenital System - Urinary retention, urination impaired, urinary incontinence, urinary frequency increased, menstrual disorders associated with increased bleeding or increased irregular bleeding (e.g., menorrhagia, metrorrhagia)
In placebo-controlled premarketing studies, there were increases in mean blood pressure (see Table 10). Across most indications, a dose-related increase in mean supine systolic and diastolic blood pressure was evident in patients treated with Effexor XR. Across all clinical studies in MDD, GAD, SAD and PD, 1.4% of patients in the Effexor XR groups experienced an increase in SDBP of ≥15 mm Hg along with a blood pressure ≥105 mm Hg, compared to 0.9% of patients in the placebo groups. Similarly, 1% of patients in the Effexor XR groups experienced an increase in SSBP of ≥20 mm Hg with a blood pressure ≥180 mm Hg, compared to 0.3% of patients in the placebo groups.
Table 10: Final On-therapy Mean Changes from Baseline in Supine Systolic (SSBP) and Diastolic (SDBP) Blood Pressure (mm Hg) in Placebo-controlled Studies
| Indication (Duration) | Effexor XR | Placebo | ||||
| ≤75 mg per day | >75 mg per day | |||||
| SSBP | SDBP | SSBP | SDBP | SSBP | SDBP | |
| MDD | ||||||
| (8-12 weeks) | -0.28 | 0.37 | 2.93 | 3.56 | -1.08 | -0.10 |
| GAD | ||||||
| (8 weeks) | -0.28 | 0.02 | 2.40 | 1.68 | -1.26 | -0.92 |
| (6 months) | 1.27 | -0.69 | 2.06 | 1.28 | -1.29 | -0.74 |
| SAD | ||||||
| (12 weeks) | -0.29 | -1.26 | 1.18 | 1.34 | -1.96 | -1.22 |
| (6 months) | -0.98 | -0.49 | 2.51 | 1.96 | -1.84 | -0.65 |
| PD | ||||||
| (10-12 weeks) | -1.15 | 0.97 | -0.36 | 0.16 | -1.29 | -0.99 |
Effexor XR treatment was associated with sustained hypertension (defined as Supine Diastolic Blood Pressure [SDBP] ≥90 mm Hg and ≥10 mm Hg above baseline for three consecutive ontherapy visits (see Table 11). An insufficient number of patients received mean doses of Effexor XR over 300 mg per day in clinical studies to fully evaluate the incidence of sustained increases in blood pressure at these higher doses.
Table 11: Sustained Elevations in SDBP in Effexor XR Premarketing Studies
| Indication | Dose Range (mg per day) | Incidence (%) |
| MDD | 75-375a | 19/705 (3) |
| GAD | 37.5-225 | 5/1011 (0.5) |
| SAD | 75-225 | 5/771 (0.6) |
| PD | 75-225 | 9/973 (0.9) |
| a Maximum recommended dosage for Effexor XR is 225 mg once daily. | ||
Effexor XR was associated with mean increases in pulse rate compared with placebo in premarketing placebo-controlled studies (see Table 12) [see WARNINGS AND PRECAUTIONS].
Table 12: Approximate Mean Final On-therapy Increase in Pulse Rate (beats/min) in Effexor XR Premarketing Placebo-controlled Studies (up to 12 Weeks Duration)
| Indication (Duration) | Effexor XR | Placebo |
| MDD | ||
| (12 weeks) | 2 | 1 |
| GAD | ||
| (8 weeks) | 2 | <1 |
| SAD | ||
| (12 weeks) | 3 | 1 |
| PD | ||
| (12 weeks) | 1 | <1 |
Serum Cholesterol
Effexor XR was associated with mean final increases in serum cholesterol concentrations compared with mean final decreases for placebo in premarketing MDD, GAD, SAD and PD clinical studies (Table 13).
Table 13: Mean Final On-therapy Changes in Cholesterol Concentrations (mg/dL) in Effexor XR Premarketing Studies
| Indication (Duration) | Effexor XR | Placebo |
| MDD | ||
| (12 weeks) | +1.5 | -7.4 |
| GAD | ||
| (8 weeks) | +1.0 | -4.9 |
| (6 months) | +2.3 | -7.7 |
| SAD | ||
| (12 weeks) | +7.9 | -2.9 |
| (6 months) | +5.6 | -4.2 |
| PD | ||
| (12 weeks) | +5.8 | -3.7 |
Effexor XR (venlafaxine hydrochloride) extended-release capsules treatment for up to 12 weeks in premarketing placebo-controlled trials for major depressive disorder was associated with a mean final on-therapy increase in serum cholesterol concentration of approximately 1.5 mg/dL compared with a mean final decrease of 7.4 mg/dL for placebo. Effexor XR treatment for up to 8 weeks and up to 6 months in premarketing placebo-controlled GAD trials was associated with mean final on-therapy increases in serum cholesterol concentration of approximately 1.0 mg/dL and 2.3 mg/dL, respectively while placebo subjects experienced mean final decreases of 4.9 mg/dL and 7.7 mg/dL, respectively. Effexor XR treatment for up to 12 weeks and up to 6 months in premarketing placebo-controlled Social Anxiety Disorder trials was associated with mean final on-therapy increases in serum cholesterol concentration of approximately 7.9 mg/dL and 5.6 mg/dL, respectively, compared with mean final decreases of 2.9 and 4.2 mg/dL, respectively, for placebo. Effexor XR treatment for up to 12 weeks in premarketing placebo-controlled panic disorder trials was associated with mean final on-therapy increases in serum cholesterol concentration of approximately 5.8 mg/dL compared with a mean final decrease of 3.7 mg/dL for placebo.
Patients treated with Effexor (immediate-release) for at least 3 months in placebo-controlled 12- month extension trials had a mean final on-therapy increase in total cholesterol of 9.1 mg/dL compared with a decrease of 7.1 mg/dL among placebo-treated patients. This increase was duration dependent over the study period and tended to be greater with higher doses. Clinically relevant increases in serum cholesterol, defined as 1) a final on-therapy increase in serum cholesterol ≥50 mg/dL from baseline and to a value ≥261 mg/dL, or 2) an average on-therapy increase in serum cholesterol ≥50 mg/dL from baseline and to a value ≥261 mg/dL, were recorded in 5.3% of venlafaxine-treated patients and 0.0% of placebo-treated patients.
Serum Triglycerides
Effexor XR was associated with mean final on-therapy increases in fasting serum triglycerides compared with placebo in premarketing clinical studies of SAD and PD up to 12 weeks (pooled data) and 6 months duration (Table 14).
Table 14: Mean Final On-therapy Increases in Triglyceride Concentrations (mg/dL) in Effexor XR Premarketing Studies
| Indication (Duration) | Effexor XR | Placebo |
| SAD | ||
| (12 weeks) | 8.2 | 0.4 |
| SAD | ||
| (6 months) | 11.8 | 1.8 |
| PD | ||
| (12 weeks) | 5.9 | 0.9 |
| PD | ||
| (6 months) | 9.3 | 0.3 |
The following adverse reactions have been identified during post-approval use of Effexor XR. 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.
Body as a Whole - Anaphylaxis, angioedema
Cardiovascular System - QT prolongation, ventricular fibrillation, ventricular tachycardia (including torsade de pointes), takotsubo cardiomyopathy
Digestive System - Pancreatitis
Hemic/Lymphatic System - Mucous membrane bleeding [see WARNINGS AND PRECAUTIONS], blood dyscrasias (including agranulocytosis, aplastic anemia, neutropenia and pancytopenia), prolonged bleeding time, thrombocytopenia
Metabolic/Nutritional - Hyponatremia [see WARNINGS AND PRECAUTIONS], Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion [see WARNINGS AND PRECAUTIONS], abnormal liver function tests, hepatitis, prolactin increased
Musculoskeletal - Rhabdomyolysis
Nervous System - Neuroleptic Malignant Syndrome (NMS) [see WARNINGS AND PRECAUTIONS], serotonergic syndrome [see WARNINGS AND PRECAUTIONS], delirium, extrapyramidal reactions (including dystonia and dyskinesia), impaired coordination and balance, tardive dyskinesia
Respiratory, Thoracic and Mediastinal Disorders - Anosmia, dyspnea, hyposmia, interstitial lung disease, pulmonary eosinophilia [see WARNINGS AND PRECAUTIONS]
Skin and Appendages - Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme
Special Senses - Angle-closure glaucoma [see WARNINGS AND PRECAUTIONS]
Table 15: Clinically Important Drug Interactions with Effexor XR
| Monoamine Oxidase Inhibitors (MAOI) | |
| Clinical Impact | The concomitant use of SNRIs, including Effexor XR, with MAOIs increases the risk of serotonin syndrome. |
| Intervention | Concomitant use of Effexor XR is contraindicated in patients taking MAOIs, including MAOIs such as linezolid or intravenous methylene blue [see DOSAGE AND ADMINISTRATION, CONTRAINDICATIONS and WARNINGS AND PRECAUTIONS]. |
| Other Serotonergic Drugs | |
| Clinical Impact | Concomitant use of Effexor XR with other serotonergic drugs (including other SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, tryptophan, and St. John's Wort) increases the risk of serotonin syndrome. |
| Intervention | Monitor for symptoms of serotonin syndrome when Effexor XR is used concomitantly with other drugs that may affect the serotonergic neurotransmitter systems. If serotonin syndrome occurs, consider discontinuation of Effexor XR and/or concomitant serotonergic drugs [see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS]. |
| Drugs that Interfere with Hemostasis | |
| Clinical Impact | Concomitant use of Effexor XR with an antiplatelet or anticoagulant drug may potentiate the risk of bleeding. This may be due to the effect of Effexor XR on the release of serotonin by platelets. |
| Intervention | Closely monitor for bleeding for patients receiving an antiplatelet or anticoagulant drug when Effexor XR is initiated or discontinued [see WARNINGS AND PRECAUTIONS]. |
| Effect of CYP3A Inhibitors | |
| Clinical Impact | Concomitant use of a CYP3A inhibitor increases the Cmax and AUC of venlafaxine and O-desmethylvenlafaxine (ODV) [see CLINICAL PHARMACOLOGY], which may increase the risk of toxicity of Effexor XR. |
| Intervention | Consider reducing the dose of Effexor XR. |
| CYP2D6 Substrates | |
| Clinical Impact | Concomitant use of Effexor XR increases Cmax and AUC of a CYP2D6 substrate, which may increase the risk of toxicity of the CYP2D6 substrate [see CLINICAL PHARMACOLOGY]. |
| Intervention | Consider reduction in dose of concomitant CYP2D6 substrates. |
The risk of using venlafaxine concomitantly with other CNS-active drugs (including alcohol) has not been systematically evaluated. Consequently, caution is advised when Effexor XR is taken concomitantly in combination with other CNS-active drugs.
Concomitant use of Effexor XR and weight loss agents is not recommended. The safety and efficacy of venlafaxine therapy in combination with weight loss agents, including phentermine, have not been established. Effexor XR is not indicated for weight loss alone or in combination with other products.
False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine have been reported in patients taking venlafaxine due to lack of specificity of the screening tests. False-positive test results may be expected for several days following discontinuation of venlafaxine therapy. Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish venlafaxine from PCP and amphetamine.
Effexor XR contains venlafaxine which is not a controlled substance.
Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects.
While venlafaxine has not been systematically studied in clinical studies for its potential for abuse, there was no indication of drug-seeking behavior in the clinical studies. However, it is not possible to predict on the basis of premarketing experience the extent to which a CNS-active drug will be misused, diverted, and/or abused once marketed. Consequently, providers should carefully evaluate patients for history of drug abuse and follow such patients closely, observing them for signs of misuse or abuse of venlafaxine (e.g., development of tolerance, incrementation of dose, drug-seeking behavior).
Physical dependence is a state that develops as a result of physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug.
In vitro studies revealed that venlafaxine has virtually no affinity for opiate, benzodiazepine, phencyclidine (PCP), or N-methyl-D-aspartic acid (NMDA) receptors.
Venlafaxine was not found to have any significant CNS stimulant activity in rodents. In primate drug discrimination studies, venlafaxine showed no significant stimulant or depressant abuse liability.
Discontinuation effects have been reported in patients receiving venlafaxine [see DOSAGE AND ADMINISTRATION and WARNINGS AND PRECAUTIONS].
Included as part of the PRECAUTIONS section.
In pooled analyses of placebo-controlled trials of antidepressant drugs (SSRIs and other antidepressant classes) that included approximately 77,000 adult patients and 4,500 pediatric patients, the incidence of suicidal thoughts and behaviors in antidepressant-treated patients age 24 years and younger was greater than in placebo-treated patients. There was considerable variation in risk of suicidal thoughts and behaviors among drugs, but there was an increased risk identified in young patients for most drugs studied. There were differences in absolute risk of suicidal thoughts and behaviors across the different indications, with the highest incidence in patients with MDD. The drug-placebo differences in the number of cases of suicidal thoughts and behaviors per 1,000 patients treated are provided in Table 1.
Table 1:Risk Differences of the Number of Patients of Suicidal Thoughts and Behaviors in the Pooled Placebo-Controlled Trials of Antidepressants in Pediatric* and Adult Patients
| Age Range | Drug-Placebo Difference in Number of Patients of Suicidal Thoughts and Behaviors per 1,000 Patients Treated |
| Increases Compared to Placebo | |
| <18 years old | 14 additional patients |
| 18-24 years old | 5 additional patients |
| Decreases Compared to Placebo | |
| 25-64 years old | 1 fewer patient |
| ≥65 years old | 6 fewer patients |
| *Effexor XR is not approved in pediatric patients. | |
It is unknown whether the risk of suicidal thoughts and behaviors in children, adolescents, and young adults extends to longer-term use, i.e., beyond four months. However, there is substantial evidence from placebo-controlled maintenance trials in adults with MDD that antidepressants delay the recurrence of depression and that depression itself is a risk factor for suicidal thoughts and behaviors.
Monitor all antidepressant-treated patients for any indication for clinical worsening and emergence of suicidal thoughts and behaviors, especially during the initial few months of drug therapy, and at times of dosage changes. Counsel family members or caregivers of patients to monitor for changes in behavior and to alert the healthcare provider. Consider changing the therapeutic regimen, including possibly discontinuing Effexor XR, in patients whose depression is persistently worse, or who are experiencing emergent suicidal thoughts or behaviors.
Serotonin-norepinephrine reuptake inhibitors (SNRIs), including Effexor XR, can precipitate serotonin syndrome, a potentially life-threatening condition. The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, meperidine, methadone, tryptophan, buspirone, amphetamines, and St. John’s Wort) and with drugs that impair metabolism of serotonin, i.e., MAOIs [see CONTRAINDICATIONS, DRUG INTERACTIONS]. Serotonin syndrome can also occur when these drugs are used alone.
Serotonin syndrome signs and symptoms may include mental status changes (e.g., agitation, hallucinations, delirium, coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, and gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea).
The concomitant use of Effexor XR with MAOIs is contraindicated. In addition, do not initiate Effexor XR in a patient being treated with MAOIs such as linezolid or intravenous methylene blue. No reports involved the administration of methylene blue by other routes (such as oral tablets or local tissue injection). If it is necessary to initiate treatment with an MAOI such as linezolid or intravenous methylene blue in a patient taking Effexor XR, discontinue Effexor XR before initiating treatment with the MAOI [see CONTRAINDICATIONS, DRUG INTERACTIONS].
Monitor all patients taking Effexor XR for the emergence of serotonin syndrome. Discontinue treatment with Effexor XR and any concomitant serotonergic agents immediately if the above symptoms occur, and initiate supportive symptomatic treatment. If concomitant use of Effexor XR with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.
In controlled trials, there were dose-related increases in systolic and diastolic blood pressure, as well as cases of sustained hypertension [see ADVERSE REACTIONS].
Monitor blood pressure before initiating treatment with Effexor XR and regularly during treatment. Control pre-existing hypertension before initiating treatment with Effexor XR. Use caution in treating patients with pre-existing hypertension or cardiovascular or cerebrovascular conditions that might be compromised by increases in blood pressure. Sustained blood pressure elevation can lead to adverse outcomes. Cases of elevated blood pressure requiring immediate treatment have been reported with Effexor XR. Consider dose reduction or discontinuation of treatment for patients who experience a sustained increase in blood pressure.
Across all clinical studies with Effexor, 1.4% of patients in the Effexor XR treated groups experienced a ≥15 mm Hg increase in supine diastolic blood pressure (SDBP) ≥105 mm Hg, compared to 0.9% of patients in the placebo groups. Similarly, 1% of patients in the Effexor XR treated groups experienced a ≥20 mm Hg increase in supine systolic blood pressure (SSBP) with blood pressure ≥180 mm Hg, compared to 0.3% of patients in the placebo groups [see ADVERSE REACTIONS]. Treatment with Effexor XR was associated with sustained hypertension defined as SDBP ≥90 mm Hg and ≥10 mm Hg above baseline for three consecutive on-therapy visits [see ADVERSE REACTIONS]. An insufficient number of patients received mean doses of Effexor XR over 300 mg per day in clinical studies to fully evaluate the incidence of sustained increases in blood pressure at these higher doses.
Drugs that interfere with serotonin reuptake inhibition, including Effexor XR, may increase the risk of bleeding events, ranging from ecchymoses, hematomas, epistaxis, petechiae, and gastrointestinal hemorrhage to life-threatening hemorrhage. Concomitant use of aspirin, Nonsteroidal Anti-Inflammatory Drugs (NSAIDs), warfarin, and other anti-coagulants or other drugs known to affect platelet function may add to this risk. Case reports and epidemiological studies (case-control and cohort design) have demonstrated an association between use of drugs that interfere with serotonin reuptake and the occurrence of gastrointestinal bleeding. Based on data from the published observational studies, exposure to SNRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage [see Use In Specific Populations].
Inform patients about the increased risk of bleeding associated with the concomitant use of Effexor XR and nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, or other drugs that affect coagulation. For patients taking warfarin, carefully monitor coagulation indices when initiating, titrating, or discontinuing Effexor XR.
The pupillary dilation that occurs following use of many antidepressant drugs including Effexor XR may trigger an angle closure attack in a patient with anatomically narrow angles who does not have a patent iridectomy. Avoid use of antidepressants, including Effexor XR, in patients with untreated anatomically narrow angles.
In patients with bipolar disorder, treating a depressive episode with Effexor XR or another antidepressant may precipitate a mixed/manic episode. Mania or hypomania was reported in Effexor XR treated patients in the premarketing studies in MDD, SAD, and PD (see Table 2). Prior to initiating treatment with Effexor XR, screen for any personal or family history of bipolar disorder, mania, or hypomania.
Table 2: Incidence (%) of Mania or Hypomania Reported in Effexor XR Treated Patients in the Premarketing Studies
| Indication | Effexor XR | Placebo |
| MDD | 0.3 | 0.0 |
| GAD | 0.0 | 0.2 |
| SAD | 0.2 | 0.0 |
| PD | 0.1 | 0.0 |
Discontinuation symptoms have been systematically evaluated in patients taking venlafaxine, including prospective analyses of clinical studies in GAD and retrospective surveys of studies in MDD and SAD. Abrupt discontinuation or dose reduction of venlafaxine at various doses has been found to be associated with the appearance of new symptoms, the frequency of which increased with increased dose level and with longer duration of treatment. Reported symptoms include agitation, anorexia, anxiety, confusion, impaired coordination and balance, diarrhea, dizziness, dry mouth, dysphoric mood, fasciculation, fatigue, flu-like symptoms, headaches, hypomania, insomnia, nausea, nervousness, nightmares, sensory disturbances (including shocklike electrical sensations), somnolence, sweating, tremor, vertigo, and vomiting.
There have been postmarketing reports of serious discontinuation symptoms which can be protracted and severe. Completed suicide, suicidal thoughts, aggression and violent behavior have been observed in patients during reduction in Effexor XR dosage, including during discontinuation. Other postmarketing reports describe visual changes (such as blurred vision or trouble focusing) and increased blood pressure after stopping or reducing the dose of Effexor XR.
During marketing of Effexor XR, other SNRIs, and SSRIs, there have been reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: irritability, lethargy, emotional lability, tinnitus, and seizures.
Patients should be monitored for these symptoms when discontinuing treatment with Effexor XR. A gradual reduction in the dose, rather than abrupt cessation, is recommended. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the healthcare provider may continue decreasing the dose, but at a more gradual rate. In some patients, discontinuation may need to occur over a period of several months [see DOSAGE AND ADMINISTRATION].
Cases of seizure have been reported with venlafaxine therapy. Effexor XR has not been systematically evaluated in patients with seizure disorder. Effexor XR should be prescribed with caution in patients with a seizure disorder.
Hyponatremia can occur as a result of treatment with SNRIs, including Effexor XR. In many cases, the hyponatremia appears to be the result of the Syndrome of Inappropriate Antidiuretic Hormone (SIADH) secretion. Cases with serum sodium lower than 110 mmol/L have been reported. Elderly patients may be at greater risk of developing hyponatremia with SNRIs. Also, patients taking diuretics, or those who are otherwise volume-depleted, may be at greater risk [see Use In Specific Populations and CLINICAL PHARMACOLOGY]. Consider discontinuation of Effexor XR in patients with symptomatic hyponatremia, and institute appropriate medical intervention.
Signs and symptoms of hyponatremia include headache, difficulty concentrating, memory impairment, confusion, weakness, and unsteadiness, which may lead to falls. Signs and symptoms associated with more severe and/or acute cases have included hallucination, syncope, seizure, coma, respiratory arrest, and death.
The average change in body weight and incidence of weight loss (percentage of patients who lost 3.5% or more) in the placebo-controlled pediatric studies in MDD, GAD, and SAD are shown in Tables 3 and 4.
Table 3: Average Change in Body Weight (kg) From Beginning of Treatment in Pediatric Patientsa in Double-blind, Placebo-controlled Studies of Effexor XR
| Indication (Duration) | Effexor XR | Placebo |
| MDD and GAD (4 pooled studies, 8 weeks) | -0.45 (n = 333) | +0.77 (n = 333) |
| SAD (16 weeks) | -0.75 (n = 137) | +0.76 (n = 148) |
| aEffexor XR is not approved for use in pediatric patients. | ||
Table 4: Incidence (%) of Pediatric Patientsa Experiencing Weight Loss (3.5% or more) in Double-blind, Placebo-controlled Studies of Effexor XR
| Indication (Duration) | Effexor XR | Placebo |
| MDD and GAD (4 pooled studies, 8 weeks) | 18b(n=333) | 3.6 (n = 333) |
| SAD (16 weeks) | 47b (n = 137) | 14 (n = 148) |
| a Effexor XR is not approved for use in pediatric patients. b p <0.001 versus placebo |
||
Weight loss was not limited to patients with anorexia [see WARNINGS AND PRECAUTIONS].
The risks associated with longer term Effexor XR use were assessed in an open-label MDD study of children and adolescents who received Effexor XR for up to six months. The children and adolescents in the study had increases in weight that were less than expected, based on data from age- and sex-matched peers. The difference between observed weight gain and expected weight gain was larger for children (<12 years old) than for adolescents (≥12 years old).
Effexor XR is not approved for use in pediatric patients [Use In Specific Populations].
Table 5 shows the average height increase in pediatric patients in the short-term, placebocontrolled MDD, GAD, and SAD studies. The differences in height increases in GAD and MDD studies were most notable in patients younger than 12 years old.
Table 5: Average Height Increases (cm) in Pediatric Patientsa in Placebo-controlled Studies of Effexor XR
| Indication(Duration) | Effexor XR | Placebo |
| MDD (8 weeks) | 0.8 (n = 146) | 0.7 (n = 147) |
| GAD (8 weeks) | 0.3b (n = 122) | 1.0 (n = 132) |
| SAD | 1.0 (n = 109) | 1.0 (n = 112) |
| a Effexor XR is not approved for use in pediatric patients. b p = 0.041 |
||
In the six-month, open-label MDD study, children and adolescents had height increases that were less than expected, based on data from age- and sex-matched peers. The difference between observed and expected growth rates was larger for children (<12 years old) than for adolescents (≥12 years old) [see Use In Specific Populations].
Decreased appetite (reported as anorexia) was more commonly observed in Effexor XR treated patients versus placebo-treated patients in the premarketing evaluation of Effexor XR for MDD, GAD, and SAD (see Table 6).
Effexor XR is not approved for use in pediatric patients [see Use In Specific Populations].
Table 6: Incidence (%) of Decreased Appetite and Associated Discontinuation Ratesa (%) in Pediatric Patientsb in Placebo-controlled Studies of Effexor XR
| Indication (Duration) | Effexor XR | Placebo | ||
| Incidence | Discontinuation | Incidence | Discontinuation | |
| MDD and GAD (pooled, 8 weeks) | 10 | 0.0 | 3 | - |
| SAD (16 weeks) | 22 | 0.7 | 3 | 0.0 |
| a The discontinuation rates for weight loss were 0.7% for patients receiving either Effexor XR or placebo. b Effexor XR is not approved for use in pediatric patients. |
||||
Interstitial lung disease and eosinophilic pneumonia associated with venlafaxine therapy have been rarely reported. The possibility of these events should be considered in Effexor XR-treated patients who present with progressive dyspnea, cough or chest discomfort. Such patients should undergo a prompt medical evaluation, and discontinuation of Effexor XR should be considered.
Use of SNRIs, including Effexor XR, may cause symptoms of sexual dysfunction [see ADVERSE REACTIONS]. In male patients, SNRI use may result in ejaculatory delay or failure, decreased libido, and erectile dysfunction. In female patients, SNRI use may result in decreased libido and delayed or absent orgasm. It is important for prescribers to inquire about sexual function prior to initiation of Effexor XR and to inquire specifically about changes in sexual function during treatment, because sexual function may not be spontaneously reported. When evaluating changes in sexual function, obtaining a detailed history (including timing of symptom onset) is important because sexual symptoms may have other causes, including the underlying psychiatric disorder.
Discuss potential management strategies to support patients in making informed decisions about treatment.
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
Advise patients and caregivers to look for the emergence of suicidality, especially early during treatment and when the dose is adjusted up or down, and instruct them to report such symptoms to the healthcare provider [see BOXED WARNING and WARNINGS AND PRECAUTIONS].
Instruct patients not to take Effexor XR with an MAOI or within 14 days of stopping an MAOI [see CONTRAINDICATIONS].
Caution patients about the risk of serotonin syndrome, particularly with the concomitant use of Effexor XR with other serotonergic drugs including triptans, tricyclic antidepressants, opioids, lithium, tryptophan, buspirone, amphetamines, St. John’s Wort, and with drugs that impair metabolism of serotonin (in particular, MAOIs, both those intended to treat psychiatric disorders and also others, such as linezolid). Instruct patients to contact their healthcare provider or report to the emergency room if they experience signs or symptoms of serotonin syndrome [see WARNINGS AND PRECAUTIONS and DRUG INTERACTIONS].
Advise patients that they should have regular monitoring of blood pressure when taking Effexor XR [see WARNINGS AND PRECAUTIONS].
Inform patients about the concomitant use of Effexor XR with NSAIDs, aspirin, other antiplatelet drugs, warfarin, or other drugs that affect coagulation because the combined use has been associated with an increased risk of bleeding. Advise patients to inform their health care providers if they are taking or planning to take any prescription or over-the-counter medications that increase the risk of bleeding [see WARNINGS AND PRECAUTIONS].
Advise patients, their families and caregivers to observe for signs of activation of mania/hypomania and instruct them to report such symptoms to the healthcare provider [see WARNINGS AND PRECAUTIONS].
Caution is advised in administering Effexor XR to patients with cardiovascular, cerebrovascular, or lipid metabolism disorders [see ADVERSE REACTIONS].
Advise patients that elevations in total cholesterol, LDL and triglycerides may occur and that measurement of serum lipids may be considered [see ADVERSE REACTIONS].
Advise patients not to abruptly stop taking Effexor XR without talking first with their healthcare provider. Patients should be aware that discontinuation effects may occur when stopping Effexor XR and they should monitor for discontinuation symptoms [see WARNINGS AND PRECAUTIONS and ADVERSE REACTIONS].
Advise patients that use of Effexor XR may cause symptoms of sexual dysfunction in both male and female patients. Inform patients that they should discuss any changes in sexual function and potential management strategies with their healthcare provider [see WARNINGS AND PRECAUTIONS].
Caution patients about operating hazardous machinery, including automobiles, until they are reasonably certain that Effexor XR therapy does not adversely affect their ability to engage in such activities.
Advise patients to avoid alcohol while taking Effexor XR [see DRUG INTERACTIONS].
Advise patients to notify their healthcare provider if they develop allergic phenomena such as rash, hives, swelling, or difficulty breathing [see CONTRAINDICATIONS and ADVERSE REACTIONS].
Advise patients to notify their healthcare provider if they become pregnant or intend to become pregnant during treatment with Effexor XR. Advise patients that Effexor XR use during mid to late pregnancy may lead to an increased risk for preeclampsia and may increase the risk for neonatal complications requiring prolonged hospitalization, respiratory support, and tube feeding. Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to Effexor XR during pregnancy [see Use In Specific Populations].
Effexor XR contains spheroids, which release the drug slowly into the digestive tract. The insoluble portion of these spheroids is eliminated, and patients may notice spheroids passing in the stool or via colostomy. Patients should be informed that the active medication has already been absorbed by the time the patient sees the spheroids.
Tumors were not increased by venlafaxine treatment in mice or rats. Venlafaxine was given by oral gavage to mice for 18 months at doses up to 120 mg/kg per day, which was 1.7 times the maximum recommended human dose on a mg/m² basis. Venlafaxine was also given to rats by oral gavage for 24 months at doses up to 120 mg/kg per day. In rats receiving the 120 mg/kg dose, plasma concentrations of venlafaxine at necropsy were 1 times (male rats) and 6 times (female rats) the plasma concentrations of patients receiving the maximum recommended human dose. Plasma levels of the ODV were lower in rats than in patients receiving the maximum recommended dose. ODV, the major human metabolite of venlafaxine, administered by oral gavage to mice and rats for 2 years did not increase the incidence of tumors in either study. Mice received ODV at dosages up to 500/300 mg/kg/day (dosage lowered after 45 weeks of dosing). The exposure at the 300 mg/kg/day dose is 9 times that of a human dose of 225 mg/day. Rats received ODV at dosages up to 300 mg/kg/day (males) or 500 mg/kg/day (females). The exposure at the highest dose is approximately 8 (males) or 11 (females) times that of a human dose of 225 mg/day.
Venlafaxine and the major human metabolite, ODV, were not mutagenic in the Ames reverse mutation assay in Salmonella bacteria or the Chinese hamster ovary/HGPRT mammalian cell forward gene mutation assay. Venlafaxine was also not mutagenic or clastogenic in the in vitro BALB/c-3T3 mouse cell transformation assay, the sister chromatid exchange assay in cultured Chinese hamster ovary cells, or in the in vivo chromosomal aberration assay in rat bone marrow. ODV was not clastogenic in the in vitro Chinese hamster ovary cell chromosomal aberration assay or in the in vivo chromosomal aberration assay in rats.
Reproduction and fertility studies of venlafaxine in rats showed no adverse effects of venlafaxine on male or female fertility at oral doses of up to 2 times the maximum recommended human dose of 225 mg/day on a mg/m² basis. However, when desvenlafaxine succinate, the major human metabolite of venlafaxine, was administered orally to male and female rats, fertility was reduced at the high dose of 300 mg/kg/day, which is 10 (males) and 19 (females) times the AUC exposure at an adult human dose of 100 mg per day. There was no effect on fertility at 100 mg/kg/day, which is 3 (males) or 5 (females) times the AUC exposure at an adult human dose of 100 mg per day. These studies did not address reversibility of the effect on fertility. The relevance of these findings to humans is not known.
There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antidepressants, including Effexor XR, during pregnancy. Healthcare providers are encouraged to register patients by calling the National Pregnancy Registry for Antidepressants at 1-844-405- 6185 or visiting online at https://womensmentalhealth.org/clinical-and-researchprograms/ pregnancyregistry/antidepressants/.
Based on data from published observational studies, exposure to SNRIs, particularly in the month before delivery, has been associated with a less than 2-fold increase in the risk of postpartum hemorrhage [see WARNINGS AND PRECAUTIONS and Clinical Considerations].
Available data from published epidemiologic studies on venlafaxine use in pregnant women have not identified a drug-associated risk of major birth defects, miscarriage or adverse fetal outcomes (see Data). Available data from observational studies with venlafaxine have identified a potential increased risk for preeclampsia when used during mid to late pregnancy; exposure to SNRIs near delivery may increase the risk for postpartum hemorrhage (see Clinical Considerations). There are risks associated with untreated depression in pregnancy and poor neonatal adaptation in newborns with exposure to SNRIs, including Effexor XR, during pregnancy (see Clinical Considerations).
In animal studies, there was no evidence of malformations or fetotoxicity following administration of venlafaxine during organogenesis at doses up to 2.5 times (rat) or 4 times (rabbit) the maximum recommended human daily dose on a mg/m² basis. Postnatal mortality and decreased pup weights were observed following venlafaxine administration to pregnant rats during gestation and lactation at 2.5 times (mg/m²) the maximum human daily dose. The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
Disease-Associated Maternal And/Or Embryo/Fetal Risk
Women who discontinue antidepressants during pregnancy are more likely to experience a relapse of major depression than women who continue antidepressants. This finding is from a prospective, longitudinal study that followed 201 pregnant women with a history of major depression who were euthymic and taking antidepressants at the beginning of pregnancy.
Consider the risk of untreated depression when discontinuing or changing treatment with antidepressant medication during pregnancy and postpartum.
Maternal Adverse Reactions
Exposure to Effexor XR in mid to late pregnancy may increase the risk for preeclampsia, and exposure to Effexor XR in the month before delivery may be associated with an increased risk of postpartum hemorrhage [see WARNINGS AND PRECAUTIONS].
Fetal/Neonatal Adverse Reactions
Neonates exposed to SNRIs late in the third trimester have developed complications requiring prolonged hospitalization, respiratory support, and tube feeding. Such complications can arise immediately upon delivery. Reported clinical findings have included respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremors, jitteriness, irritability, and constant crying. These findings are consistent with either a direct toxic effect of SNRIs or possibly a drug discontinuation syndrome. It should be noted that, in some cases, the clinical picture is consistent with serotonin syndrome [see WARNINGS AND PRECAUTIONS]. Monitor neonates who were exposed to Effexor XR in the third trimester of pregnancy for drug discontinuation syndrome (see Data).
Human Data
Published epidemiological studies of pregnant women exposed to venlafaxine have not established an increased risk of major birth defects, miscarriage or other adverse developmental outcomes. Methodological limitations may both fail to identify true findings and also identify findings that are not true.
Retrospective cohort studies based on claims data have shown an association between venlafaxine use and preeclampsia, compared to depressed women who did not take an antidepressant during pregnancy. One study that assessed venlafaxine exposure in the second trimester or first half of the third trimester and preeclampsia showed an increased risk compared to unexposed depressed women (adjusted [adj] RR 1.57, 95% confidence interval [CI] 1.29- 1.91). Preeclampsia was observed at venlafaxine doses equal to or greater than 75 mg per day and a duration of treatment >30 days. Another study that assessed venlafaxine exposure in gestational weeks 10-20 and preeclampsia showed an increased risk at doses equal to or greater than 150 mg per day. Available data are limited by possible outcome misclassification and possible confounding due to depression severity and other confounders.
Retrospective cohort studies based on claims data have suggested an association between venlafaxine use near the time of delivery or through delivery and postpartum hemorrhage. One study showed an increased risk for postpartum hemorrhage when venlafaxine exposure occurred through delivery, compared to unexposed depressed women (adj RR 2.24 [95% CI 1.69-2.97]).
There was no increased risk in women who were exposed to venlafaxine earlier in pregnancy. Limitations of this study include possible confounding due to depression severity and other confounders. Another study showed an increased risk for postpartum hemorrhage when SNRI exposure occurred for at least 15 days in the last month of pregnancy or through delivery, compared to unexposed women (adj RR 1.64-1.76). The results of this study may be confounded by the effects of depression.
Animal Data
Venlafaxine did not cause malformations in offspring of rats or rabbits given doses up to 2.5 times (rat) or 4 times (rabbit) the maximum recommended human daily dose on a mg/m² basis. However, in rats, there was a decrease in pup weight, an increase in stillborn pups, and an increase in pup deaths during the first 5 days of lactation, when dosing began during pregnancy and continued until weaning. The cause of these deaths is not known. These effects occurred at 2.5 times (mg/m²) the maximum human daily dose. The no effect dose for rat pup mortality was 0.25 times the human dose on a mg/m² basis.
When desvenlafaxine succinate, the major metabolite of venlafaxine, was administered orally to pregnant rats and rabbits during the period of organogenesis at doses up to 300 mg/kg/day and 75 mg/kg/day, respectively, no fetal malformations were observed. These doses were associated with a plasma exposure (AUC) 19 times (rats) and 0.5 times (rabbits) the AUC exposure at an adult human dose of 100 mg per day. However, fetal weights were decreased and skeletal ossification was delayed in rats in association with maternal toxicity at the highest dose, with an AUC exposure at the no-effect dose that is 4.5-times the AUC exposure at an adult human dose of 100 mg per day.
Data from published literature report the presence of venlafaxine and its active metabolite in human milk and have not shown adverse reactions in breastfed infants (see Data). There are no data on the effects of venlafaxine on milk production.
The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Effexor XR and any potential adverse effects on the breastfed child from Effexor XR or from the underlying maternal condition.
In a lactation study conducted in 11 breastfeeding women (at a mean of 20.1 months postpartum) who were taking a mean daily dose of 194.3 mg of venlafaxine and in a lactation study conducted in 6 breastfeeding women who were taking a daily dose of 225 mg to 300 mg of venlafaxine (at a mean of 7 months post-partum), the estimated mean relative infant dose was 8.1% and 6.4% based on the sum of venlafaxine and its major metabolite, desvenlafaxine. No adverse reactions were seen in the infants.
Safety and effectiveness of Effexor XR in pediatric patients have not been established.
Two placebo-controlled trials in 766 pediatric patients with MDD and two placebo-controlled trials in 793 pediatric patients with GAD have been conducted with Effexor XR, and the data were not sufficient to support use in pediatric patients.
In the studies conducted in pediatric patients ages 6 to 17 years, the occurrence of blood pressure and cholesterol increases was considered to be clinically relevant in pediatric patients and was similar to that observed in adult patients [see WARNINGS AND PRECAUTIONS, ADVERSE REACTIONS]. The following adverse reactions were also observed in pediatric patients: abdominal pain, agitation, dyspepsia, ecchymosis, epistaxis, and myalgia.
Although no studies have been designed to primarily assess Effexor XR’s impact on the growth, development, and maturation of children and adolescents, the studies that have been done suggest that Effexor XR may adversely affect weight and height [see WARNINGS AND PRECAUTIONS]. Decreased appetite and weight loss were observed in placebo-controlled studies of pediatric patients 6 to 17 years.
In pediatric clinical studies, the adverse reaction, suicidal ideation, was observed. Antidepressants increased the risk of suicidal thoughts and behaviors in pediatric patients [see BOXED WARNING, WARNINGS AND PRECAUTIONS].
The percentage of patients in clinical studies for Effexor XR for MDD, GAD, SAD, and PD who were 65 years of age or older are shown in Table 16.
Table 16: Percentage (and Number of Patients Studied) of Patients 65 Years of Age and Older by Indicationa
| Indication | Effexor XR |
| MDD | 4 (14/357) |
| GAD | 6 (77/1,381) |
| SAD | 1 (10/819) |
| PD | 2 (16/1,001) |
| a In addition, in the premarketing assessment of Effexor (immediate-release), 12% (357/2,897) of patients were ≥ 65 years of age. | |
No overall differences in effectiveness or safety were observed between geriatric patients and younger patients, and other reported clinical experience generally has not identified differences in response between the elderly and younger patients. However, greater sensitivity of some older individuals cannot be ruled out. SSRIs and SNRIs, including Effexor XR, have been associated with cases of clinically significant hyponatremia in elderly patients, who may be at greater risk for this adverse event [see WARNINGS AND PRECAUTIONS].
The pharmacokinetics of venlafaxine and ODV are not substantially altered in the elderly [see CLINICAL PHARMACOLOGY] (see Figure 1). No dose adjustment is recommended for the elderly on the basis of age alone, although other clinical circumstances, some of which may be more common in the elderly, such as renal or hepatic impairment, may warrant a dose reduction [see DOSAGE AND ADMINISTRATION].
Dosage adjustment is recommended in patients with mild (Child-Pugh Class A), moderate (Child-Pugh Class B), or severe (Child-Pugh Class C) hepatic impairment or hepatic cirrhosis [see DOSAGE AND ADMINISTRATION and CLINICAL PHARMACOLOGY].
Dosage adjustment is recommended in patients with mild (CLcr = 60-89 mL/min), moderate (CLcr = 30-59 mL/min), or severe (CLcr <30 mL/min) renal impairment, and in patients undergoing hemodialysis [see DOSAGE AND ADMINISTRATION and CLINICAL PHARMACOLOGY].
During the premarketing evaluations of Effexor XR (for MDD, GAD, SAD, and PD) and Effexor (for MDD), there were twenty reports of acute overdosage with Effexor (6 and 14 reports in Effexor XR and Effexor patients, respectively), either alone or in combination with other drugs and/or alcohol.
Somnolence was the most commonly reported symptom. Among the other reported symptoms were paresthesia of all four limbs, moderate dizziness, nausea, numb hands and feet, and hotcold spells 5 days after the overdose. In most cases, no signs or symptoms were associated with overdose. The majority of the reports involved ingestion in which the total dose of venlafaxine taken was estimated to be no more than several-fold higher than the usual therapeutic dose. One patient who ingested 2.75 g of venlafaxine was observed to have two generalized convulsions and a prolongation of QTc to 500 msec, compared with 405 msec at baseline. Mild sinus tachycardia was reported in two of the other patients.
Actions taken to treat the overdose included no treatment, hospitalization and symptomatic treatment, and hospitalization plus treatment with activated charcoal. All patients recovered.
In postmarketing experience, overdose with venlafaxine has occurred predominantly in combination with alcohol and/or other drugs. The most commonly reported events in overdosage include tachycardia, changes in level of consciousness (ranging from somnolence to coma), mydriasis, seizures, and vomiting. Electrocardiogram changes (e.g., prolongation of QT interval, bundle branch block, QRS prolongation), ventricular tachycardia, bradycardia, hypotension, rhabdomyolysis, vertigo, liver necrosis, serotonin syndrome, and death have been reported.
Published retrospective studies report that venlafaxine overdosage may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants. Epidemiological studies have shown that venlafaxine-treated patients have a higher preexisting burden of suicide risk factors than SSRItreated patients. The extent to which the finding of an increased risk of fatal outcomes can be attributed to the toxicity of venlafaxine in overdosage, as opposed to some characteristic(s) of venlafaxine-treated patients, is not clear. Prescriptions for Effexor XR should be written for the smallest quantity of capsules consistent with good patient management, in order to reduce the risk of overdose.
No specific antidotes for Effexor XR are known. In managing overdosage, consider the possibility of multiple drug involvement. Consider contacting a Poison Center (1-800-222-1222) or a medical toxicologist for overdosage management recommendations for Effexor XR.
Effexor XR is contraindicated in patients:
The mechanism of action of venlafaxine in the treatment of MDD, GAD, SAD, and PD is unclear, but is thought to be related to the potentiation of serotonin and norepinephrine in the central nervous system, through inhibition of their reuptake.
In vitro studies have demonstrated that venlafaxine and its active metabolite, Odesmethylvenlafaxine (ODV), are potent and selective inhibitors of neuronal serotonin and norepinephrine reuptake and weak inhibitors of dopamine reuptake. Venlafaxine and ODV have no significant affinity for muscarinic-cholinergic, H1-histaminergic, or α1-adrenergic receptors in vitro. Pharmacologic activity at these receptors is hypothesized to be associated with the various anticholinergic, sedative, and cardiovascular effects seen with other psychotropic drugs. Venlafaxine and ODV do not possess monoamine oxidase (MAO) inhibitory activity.
The effect of venlafaxine on the QT interval was evaluated in a randomized, double-blind, placebo- and positive-controlled three-period crossover thorough QT study in 54 healthy adult subjects. No significant QT prolongation effect of venlafaxine at 450 mg (2 times the maximum recommended dosage) was detected.
Venlafaxine and ODV steady-state concentrations are reached within 3 days. Venlafaxine and ODV exhibited linear kinetics over the dosage range of 75 to 450 mg per day (0.33 to 2 times the maximum recommended dosage). Time of administration (AM versus PM) did not affect the pharmacokinetics of venlafaxine and ODV from the 75 mg Effexor XR capsule.
Venlafaxine is well absorbed. On the basis of mass balance studies, at least 92% of a single oral dose of venlafaxine is absorbed. The absolute bioavailability of venlafaxine is approximately 45%.
Administration of Effexor XR (150 mg once daily) generally resulted in lower Cmax and later Tmax values than for Effexor administered twice daily (Table 17). When equal daily doses of venlafaxine were administered as either an immediate-release tablet or the extended-release capsule, the exposure to both venlafaxine and ODV was similar for the two treatments, and the fluctuation in plasma concentrations was slightly lower with the Effexor XR capsule. Therefore, Effexor XR provides a slower rate of absorption, but the same extent of absorption compared with the immediate-release tablet.
Table 17: Comparison of Cmax and Tmax Values for Venlafaxine and ODV Following Oral Administration of Effexor XR and Effexor (Immediate-Release)
| Venlafaxine | ODV | |||
| Cmax (ng/mL) | Tmax (h) | Cmax (ng/mL) | Tmax (h) | |
| Effexor XR (150 mg once daily) | 150 | 5.5 | 260 | 9 |
| Effexor (75 mg twice daily) | 225 | 2 | 290 | 3 |
Effect Of Food
Food did not affect the bioavailability of venlafaxine or its active metabolite, ODV.
Venlafaxine is 27% and ODV is 30% bound to plasma proteins. The apparent volume of distribution at steady-state is 7.5 ± 3.7 L/kg for venlafaxine and 5.7 ± 1.8 L/kg for ODV.
Mean ± SD plasma apparent clearance at steady-state is 1.3 ± 0.6 L/h/kg for venlafaxine and 0.4 ± 0.2 L/h/kg for ODV. The apparent elimination half-life is 5 ± 2 hours for venlafaxine and 11 ± 2 hours for ODV.
Metabolism
Following absorption, venlafaxine undergoes extensive presystemic metabolism in the liver, primarily to ODV, but also to N-desmethylvenlafaxine, N,O-didesmethylvenlafaxine, and other minor metabolites. In vitro studies indicate that the formation of ODV is catalyzed by CYP2D6; this has been confirmed in a clinical study showing that patients with low CYP2D6 levels (poor metabolizers) had increased levels of venlafaxine and reduced levels of ODV compared to people with normal CYP2D6 levels (extensive metabolizers) (see Figure 1).
Excretion
Approximately 87% of a venlafaxine dose is recovered in the urine within 48 hours as unchanged venlafaxine (5%), unconjugated ODV (29%), conjugated ODV (26%), or other minor inactive metabolites (27%).
The effect of intrinsic patient factors on the pharmacokinetics of venlafaxine and its active metabolite ODV is presented in Figure 1.
Figure 1: Pharmacokinetics of Venlafaxine and Active Metabolite O-desmethylvenlafaxine (ODV) in Special Populations
 |
ODV=O-desmethylvenlafaxine; AUC=area under the curve; Cmax=peak plasma concentrations.
* Similar effect is expected with strong CYP2D6 inhibitors.
Effect Of Other Drugs On Effexor XR And Active Metabolite ODV
The effects of other drugs on the exposure of venlafaxine and ODV are summarized in Figure 2.
Figure 2: Effect of Other Drugs on the Pharmacokinetics of Venlafaxine and Active Metabolite O-desmethylvenlafaxine (ODV)
 |
ODV=O-desmethylvenlafaxine; AUC=area under the curve; Cmax=peak plasma concentrations; EM’s=extensive metabolizers; PM’s=poor metabolizers.
The effects of Effexor XR on the exposure of other drugs are summarized in Figure 3.
Figure 3: Effect of Venlafaxine on the Pharmacokinetics of Interacting Drugs and their Active Metabolites
 |
AUC=area under the curve; Cmax=peak plasma concentrations; OH=hydroxyl.
* Data for 2-OH desipramine were not plotted to enhance clarity; the fold change and 90% CI for Cmax and AUC of 2-OH desipramine were 6.6 (5.5, 7.9) and 4.4 (3.8, 5.0), respectively.
Note: *Administration of venlafaxine in a stable regimen did not exaggerate the psychomotor and psychometric effects induced by ethanol in these same subjects when they were not receiving venlafaxine.
The efficacy of Effexor XR (venlafaxine hydrochloride) extended-release capsules as a treatment for Major Depressive Disorder (MDD) was established in two placebo-controlled, short-term (8 weeks for study 1; 12 weeks for study 2), flexible-dose studies, with doses starting at 75 mg per day and ranging to 225 mg per day in adult outpatients meeting DSM-III-R or DSM-IV criteria for MDD. In moderately depressed outpatients, the initial dose of venlafaxine was 75 mg per day. In both studies, Effexor XR demonstrated superiority over placebo on the primary efficacy measure defined as change from baseline in the HAM-D-21 total score to the endpoint visit, Effexor XR also demonstrated superiority over placebo on the key secondary efficacy endpoint, the Clinical Global Impressions (CGI) Severity of Illness scale. Examination of gender subsets of the population studied did not reveal any differential responsiveness on the basis of gender.
A 4-week study of inpatients meeting DSM-III-R criteria for MDD with melancholia utilizing Effexor in a range of 150 to 375 mg per day (divided in a three-times-a-day schedule) demonstrated superiority of Effexor over placebo based on the HAM-D-21 total score. The mean dose in completers was 350 mg per day (study 3).
In a longer-term study, adult outpatients with MDD who had responded during an 8-week openlabel study on Effexor XR (75, 150, or 225 mg, once daily every morning) were randomized to continuation of their same Effexor XR dose or to placebo, for up to 26 weeks of observation for relapse. Response during the open-label phase was defined as a CGI Severity of Illness item score of ≤3 and a HAM-D-21 total score of ≤10 at the day 56 evaluation. Relapse during the double-blind phase was defined as follows: (1) a reappearance of major depressive disorder as defined by DSM-IV criteria and a CGI Severity of Illness item score of ≥4 (moderately ill), (2) 2 consecutive CGI Severity of Illness item scores of ≥4, or (3) a final CGI Severity of Illness item score of ≥4 for any patient who withdrew from the study for any reason. Patients receiving continued Effexor XR treatment experienced statistically significantly lower relapse rates over the subsequent 26 weeks compared with those receiving placebo (study 4).
In a second longer term trial, adult outpatients with MDD, recurrent type, who had responded (HAM-D-21 total score ≤12 at the day 56 evaluation) and continued to be improved [defined as the following criteria being met for days 56 through 180: (1) no HAM-D-21 total score ≥20; (2) no more than 2 HAM-D-21 total scores >10, and (3) no single CGI Severity of Illness item score ≥4 (moderately ill)] during an initial 26 weeks of treatment on Effexor [100 to 200 mg per day, on a twice daily schedule] were randomized to continuation of their same Effexor dose or to placebo. The follow-up period to observe patients for relapse, defined as a CGI Severity of Illness item score ≥4, was for up to 52 weeks. Patients receiving continued Effexor treatment experienced statistically significantly lower relapse rates over the subsequent 52 weeks compared with those receiving placebo (study 5).
Table 18: Primary Efficacy Results for Studies in Major Depressive Disorder in Adults (Studies 1, 2, 3)
| Study Number | Treatment Group | Mean Baseline Score (SD) | Primary Efficacy Measure: HAM-D Score | |
| LS Mean Change from Baseline | Placebo Subtracted Differencea (95%CI) | |||
| Study 1 | Effexor (XR 75-225 mg/day)* | 24.5 | -11.7 | -4.45 (-6.66, -2.25) |
| Placebo | 23.6 | -7.24 | - | |
| Study 2 | Effexor (XR 75-225 mg/day)* | 24.5 | -15.11 | -6.40 (-8.45, -4.34) |
| Placebo | 24.9 | -8.71 | ||
| Study 3 | Effexor (IR 150-375 mg/day)* | 28.2 (0.5) | -14.9 | -10.2 (-14.4, -6.0) |
| Placebo | 28.6 (0.6) | -4.7 | - | |
| SD=standard deviation; LS Mean=least-squares mean; CI=confidence interval. a Difference (drug minus placebo) in least-squares mean change from baseline. * Doses statistically significantly superior to placebo. |
||||
The efficacy of Effexor XR as a treatment for Generalized Anxiety Disorder (GAD) was established in two 8-week, placebo-controlled, fixed-dose studies (75 to 225 mg per day), one 6- month, placebo-controlled, flexible-dose study (75 to 225 mg per day), and one 6-month, placebo-controlled, fixed-dose study (37.5, 75, and 150 mg per day) in adult outpatients meeting DSM-IV criteria for GAD.
In one 8-week study, Effexor XR demonstrated superiority over placebo for the 75, 150, and 225 mg per day doses as measured by the Hamilton Rating Scale for Anxiety (HAM-A) total score, both the HAM-A anxiety and tension items, and the Clinical Global Impressions (CGI) scale. However, the 75 and 150 mg per day doses were not as consistently effective as the highest dose (study 1). A second 8-week study evaluating doses of 75 and 150 mg per day and placebo showed that both doses were more effective than placebo on some of these same outcomes; however, the 75 mg per day dose was more consistently effective than the 150 mg per day dose (study 2). A dose-response relationship for effectiveness in GAD was not clearly established in the 75 to 225 mg per day dose range studied.
Two 6-month studies, one evaluating Effexor XR doses of 37.5, 75, and 150 mg per day (study 3) and the other evaluating Effexor XR doses of 75 to 225 mg per day (study 4), showed that daily doses of 75 mg or higher were more effective than placebo on the HAM-A total, both the HAM-A anxiety and tension items, and the CGI scale during 6 months of treatment. While there was also evidence for superiority over placebo for the 37.5 mg per day dose, this dose was not as consistently effective as the higher doses.
Examination of gender subsets of the population studied did not reveal any differential responsiveness on the basis of gender.
Table 19: Primary Efficacy Results for Studies in Generalized Anxiety Disorder in Adults (Studies 1, 2, 3, 4)
| Study Number | Treatment Group | Primary Efficacy Measure: HAM-A Score | ||
| Mean Baseline Score (SD) | LS Mean Change from Baseline (SE)* | Placebo Subtracted Differencea (95% CI) | ||
| Study 1 | Ven XR 75 mg | 24.7 | -11.1 (0.95) | -1.5 (-3.8, 0.8) |
| Ven XR 150 mg | 24.5 | -11.7 (0.87) | -2.2 (-4.5, 0.1) |
|
| Ven XR 225 mg | 23.6 | -12.1 (0.81) | -2.6 (-4.9, -0.3) |
|
| Placebo | 24.1 | -9.5 (0.85) | ||
| Study 2 | Ven XR 75 mg | 23.7 | -10.6 (0.82) | -2.6 (-4.6, -0.5) |
| Ven XR 150 mg | 23.0 | -9.8 (0.86) | -1.7 (-3.8, 0.3) |
|
| Placebo | 23.7 | -8.0 (0.73) | ||
| Study 3 | Ven XR 37.5 mg | 26.6 (0.4) | -13.8 | -2.8 (-5.1, -0.6) |
| Ven XR 75 mg | 26.3 (0.4) | -15.5 | -4.6 (-6.9, -2.3) |
|
| Ven XR150 mg | 26.3 (0.4) | -16.4 | -5.5 (-7.8, -3.1) |
|
| Placebo | 26.7 (0.5) | -11.0 | ||
| Study 4 | Ven XR 75-225 mg | 25.0 | -13.4 (0.79) | - 4.7 (-6.6, -2.9) |
| Placebo | 24.9 | -8.7 (0.70) | ||
| SD=standard deviation; SE=standard error; LS Mean=least-squares mean; CI=confidence interval. a Difference (drug minus placebo) in least-squares mean change from baseline. * Doses statistically significantly superior to placebo. |
||||
The efficacy of Effexor XR as a treatment for Social Anxiety Disorder (SAD) was established in four double-blind, parallel-group, 12-week, multicenter, placebo-controlled, flexible-dose studies (studies 1-4) and one double-blind, parallel-group, 6-month, placebo-controlled, fixed/flexibledose study, which included doses in a range of 75 to 225 mg per day in adult outpatients meeting DSM-IV criteria for SAD (study 5).
In these five studies, Effexor XR was statistically significantly more effective than placebo on change from baseline to endpoint on the Liebowitz Social Anxiety Scale (LSAS) total score. There was no evidence for any greater effectiveness of the 150 to 225 mg per day group compared to the 75 mg per day group in the 6-month study.
Examination of subsets of the population studied did not reveal any differential responsiveness on the basis of gender. There was insufficient information to determine the effect of age or race on outcome in these studies.
Table 20: Primary Efficacy Results for Studies in Social Anxiety Disorder in Adults (Studies 1, 2, 3, 4, 5)
| Study Number | Treatment Group | Primary Efficacy Measure: LSAS Score | ||
| Mean Baseline Score (SD) | LS Mean Change from Baseline (SE) | Placebo Subtracted Differencea (95% CI) | ||
| Study 1 | Ven XR (75-225 mg)* | 91.1 | -31.0 (2.22) | 11.2 (-5.3, -17.1) |
| Placebo | 86.7 | -19.9 (2.22) | - | |
| Study 2 | Ven XR (75-225 mg)* | 90.8 | -32.8 (2.69) | -10.7 (-3.7, -17.6) |
| Placebo | 87.4 | -22.1 (2.66) | - | |
| Study 3 | Ven XR (75-225 mg)* | 83.2 | -36.0 (2.35) | -16.9 (-22.6, -11.2) |
| Placebo | 83.6 | -19.1 (2.40) | -12.7 (-6.5, -19.0) |
|
| Study 4 | Ven XR (75-225 mg)* | 86.2 | -35.0 (2.64) | -14.6 (-21.8, -7.4) |
| Placebo | 86.1 | -22.2 (2.47) | ||
| Study 5 | Ven XR 75 mg | 91.8 | -38.1 (3.16) | -14.6 (-21.8, -7.4) |
| Ven XR (150-225 mg)* | 86.2 | -37.6 (3.05) | -14.1 (-21.3, -6.9) |
|
| Placebo | 89.3 | -23.5 (3.08) | ||
| SD=standard deviation; SE=standard error; LS Mean=least-squares mean; CI=confidence interval. a Difference (drug minus placebo) in least-squares mean change from baseline. * Doses statistically significantly superior to placebo. |
||||
The efficacy of Effexor XR as a treatment for Panic Disorder (PD) was established in two double-blind, 12-week, multicenter, placebo-controlled studies in adult outpatients meeting DSM-IV criteria for PD, with or without agoraphobia. Patients received fixed doses of 75 or 150 mg per day in one study (study 1) and 75 or 225 mg per day in the other study (study 2).
Efficacy was assessed on the basis of outcomes in three variables: (1) percentage of patients free of full-symptom panic attacks on the Panic and Anticipatory Anxiety Scale (PAAS); (2) mean change from baseline to endpoint on the Panic Disorder Severity Scale (PDSS) total score; and (3) percentage of patients rated as responders (much improved or very much improved) on the Clinical Global Impressions (CGI) Improvement scale. In these two studies, Effexor XR was statistically significantly more effective than placebo (for each fixed dose) on all three endpoints, but a dose-response relationship was not clearly established.
Examination of subsets of the population studied did not reveal any differential responsiveness on the basis of gender. There was insufficient information to determine the effect of age or race on outcome in these studies.
In a longer term study (study 3), adult outpatients meeting DSM-IV criteria for PD who had responded during a 12-week open phase with Effexor XR (75 to 225 mg per day) were randomly assigned to continue the same Effexor XR dose (75, 150, or 225 mg) or switch to placebo for observation for relapse under double-blind conditions. Response during the open phase was defined as ≤ 1 full-symptom panic attack per week during the last 2 weeks of the open phase and a CGI Improvement score of 1 (very much improved) or 2 (much improved). Relapse during the double-blind phase was defined as having 2 or more full-symptom panic attacks per week for 2 consecutive weeks or having discontinued due to loss of effectiveness as determined by the investigators during the study. Randomized patients were in response status for a mean time of 34 days prior to being randomized. In the randomized phase following the 12-week open-label period, patients receiving continued Effexor XR experienced a statistically significantly longer time to relapse.
Table 21: Primary Efficacy Results for Studies in Panic Disorder in Adults (Studies 1 and 2)
| Study Treatment Group Number | Primary Efficacy Measure: Whether Free of Full-symptom Panic Attacks | |||
| Percent of Patients Free of Full Symptom Panic Attack | Adjusted Odds Ratioa to Placebo | Adjusted Odds Ratioa 95% Confidence Interval | ||
| Study 1 | Ven XR 75 mg* | 54.1% (85/157) | 2.268 | (1.43, 3.59) |
| Ven XR 150 mg* | 61.4% (97/158) | 3.035 | (1.91, 4.82) | |
| Placebo | 34.4% (53/154) | -- | -- | |
| Study 2 | Ven XR 75 mg* | 64.1% (100/156) | 2.350 | (1.46, 3.78) |
| Ven XR 225 mg* | 70.0% (112/160) | 2.890 | (1.80, 4.64) | |
| Placebo | 46.5% (73/157) | -- | -- | |
| a Odds ratio (drug to placebo) in terms of probability of free of full-symptom panic attacks based on logistic regression model. 95% CI: 95% confidence interval without adjusting for multiple dose arms. * Doses statistically significantly superior to placebo. |
||||
EFFEXOR XR
(e-fex-or XR)
(venlafaxine extended-release) capsules
What is the most important information I should know about EFFEXOR XR?
EFFEXOR XR may cause serious side effects, including:
How can I watch for and try to prevent suicidal thoughts and actions in myself or a family member?
Call your healthcare provider or get emergency help right away if you or a family member have any of the following symptoms, especially if they are new, worse, or worry you:
What is EFFEXOR XR?
EFFEXOR XR is a prescription medicine used to treat adults with:
It is not known if EFFEXOR XR is safe and effective for use in children.
Do not take EFFEXOR XR if you:
Ask your healthcare provider or pharmacist if you are not sure if you take an MAOI, including MAOIs such as linezolid or intravenous methylene blue.
Do not start taking an MAOI for at least 7 days after you stop treatment with EFFEXOR XR.
Before taking EFFEXOR XR tell your healthcare provider about all your medical conditions, including if you:
Tell your healthcare provider about all the medicines you take, including prescription and over-the counter medicines, vitamins, and herbal supplements.
EFFEXOR XR and other medicines may affect each other causing possible serious side effects. EFFEXOR XR may affect the way other medicines work and other medicines may affect the way EFFEXOR XR works.
Especially tell your healthcare provider if you take:
Ask your healthcare provider if you are not sure if you are taking any of these medicines. Your healthcare provider can tell you if it is safe to take EFFEXOR XR with your other medicines.
Do not start or stop any other medicines during treatment with EFFEXOR XR without first talking to your healthcare provider. Stopping EFFEXOR XR suddenly may cause you to have serious side effects. See “What are the possible side effects of EFFEXOR XR?”
Know the medicines you take. Keep a list of them to show to your healthcare provider and pharmacist when you get a new medicine.
How should I take EFFEXOR XR?
What should I avoid while taking EFFEXOR XR?
What are the possible side effects of EFFEXOR XR?
EFFEXOR XR may cause serious side effects, including:
In severe or more sudden cases, signs and symptoms include:
Symptoms in males may include:
Symptoms in females may include:
Talk to your healthcare provider if you develop any changes in your sexual function or if you have any questions or concerns about sexual problems during treatment with EFFEXOR XR. There may be treatments your healthcare provider can suggest.
Your healthcare provider may tell you to stop taking EFFEXOR XR if you develop serious side effects during treatment with EFFEXOR XR.
The most common side effects of EFFEXOR XR include:
These are not all the possible side effects of EFFEXOR XR.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA- 1088.
How should I store EFFEXOR XR?
Keep EFFEXOR XR and all medicines out of the reach of children.
General information about the safe and effective use of EFFEXOR XR.
Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use EFFEXOR XR for a condition for which it was not prescribed. Do not give EFFEXOR XR to other people, even if they have the same symptoms that you have. It may harm them. You can ask your healthcare provider or pharmacist for information about EFFEXOR XR that is written for healthcare professionals.
What are the ingredients in EFFEXOR XR?
Active ingredient: venlafaxine
Inactive ingredients: cellulose, ethylcellulose, gelatin, hypromellose, iron oxide, and titanium dioxide.
This Medication was approved by the U.S. Food and Drug Administration.
