Warnings for Pretomanid Tablets
Included as part of the "PRECAUTIONS" Section
Precautions for Pretomanid Tablets
Risks Associated With The Combination Treatment Regimen
Pretomanid Tablet is indicated for use as part of a regimen in combination with bedaquiline and linezolid. Refer to the prescribing information for bedaquiline and linezolid for additional risk information. Warnings and Precautions related to bedaquiline and linezolid also apply to their use in the combination regimen with Pretomanid Tablets.
Hepatotoxicity
Hepatic adverse reactions were reported with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid [see Risks Associated With The Combination Treatment Regimen, and ADVERSE REACTIONS ]. Avoid alcohol and hepatotoxic agents, including herbal supplements and drugs other than bedaquiline and linezolid [see INDICATIONS] while on Pretomanid Tablets, especially in patients with impaired hepatic function.
Monitor symptoms and signs (such as fatigue, anorexia, nausea, jaundice, dark urine, liver tenderness, and hepatomegaly) and laboratory tests (ALT, AST, alkaline phosphatase, and bilirubin) at a minimum at baseline, at two weeks, and then monthly while on treatment and as needed. If evidence of new or worsening liver dysfunction occurs, test for viral hepatitides and discontinue other hepatotoxic medications. Interrupt treatment with the entire regimen if:
- Aminotransferase elevations are accompanied by total bilirubin elevation greater than 2 times the upper limit of normal.
- Aminotransferase elevations are greater than 8 times the upper limit of normal.
- Aminotransferase elevations are greater than 5 times the upper limit of normal and persist beyond 2 weeks.
Myelosuppression
Myelosuppression (including anemia, leukopenia, thrombocytopenia, and pancytopenia) was reported with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid. Myelosuppression is a known adverse reaction of linezolid. Anemia can be life threatening [see Risks Associated With The Combination Treatment Regimen, and ADVERSE REACTIONS]. When linezolid dosing, as part of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid, was reduced, interrupted, or discontinued, the observed hematologic abnormalities were reversible. Complete blood counts should be monitored at a minimum at baseline, at two weeks, and then monthly in patients receiving linezolid as part of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid. Decreasing linezolid to half the initial dose or interrupting linezolid dosing should be considered in patients who develop or have worsening myelosuppression [see DOSAGE AND ADMINISTRATION].
Peripheral And Optic Neuropathy
Peripheral neuropathy and optic neuropathy were reported with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid [see Risks Associated With The Combination Treatment Regimen, and ADVERSE REACTIONS]. Neuropathy is a known adverse reaction of long-term linezolid use. Neuropathy associated with linezolid is generally reversible or improved with appropriate monitoring and interruption, dose reduction, or discontinuation of linezolid dosing. When improvement in the peripheral neuropathy is observed, consider resuming linezolid at half the initial dose [see DOSAGE AND ADMINISTRATION]. Monitor visual function in all patients receiving the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid; if a patient experiences symptoms of visual impairment, interrupt linezolid dosing and obtain prompt ophthalmologic evaluation.
QT Prolongation
QT prolongation was reported with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid [see Risks Associated With The Combination Treatment Regimen, ADVERSE REACTIONS, and CLINICAL PHARMACOLOGY]. QT prolongation is a known adverse reaction of bedaquiline. Obtain an ECG before initiation of treatment, and at least 2, 12, and 24 weeks after starting treatment with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid. Obtain serum potassium, calcium, and magnesium at baseline and correct if abnormal. Monitor these electrolytes if QT prolongation is detected [see ADVERSE REACTIONS].
The following may increase the risk for QT prolongation when patients are receiving bedaquiline as part of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid: a history of Torsade de Pointes, congenital long QT syndrome, ongoing hypothyroidism, ongoing bradyarrhythmia, uncompensated heart failure, or serum calcium, magnesium, or potassium levels below the lower limits of normal. If necessary, bedaquiline treatment initiation could be considered in these patients after a favorable benefit-risk assessment and with frequent ECG monitoring.
Discontinue the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid if the patient develops clinically significant ventricular arrhythmia or a QTcF interval of greater than 500 ms (confirmed by repeat ECG). If syncope occurs, obtain an ECG to detect QT prolongation.
Drug Interactions
CYP3A4 Inducers
Pretomanid may be in part metabolized by CYP3A4 [see DRUG INTERACTIONS and CLINICAL PHARMACOLOGY]. Avoid co-administration of strong or moderate CYP3A4 inducers, such as rifampin or efavirenz, during treatment with pretomanid.
Reproductive Effects
Pretomanid caused testicular atrophy and impaired fertility in male rats. Advise patients of reproductive toxicities seen in animal studies and that the potential effects on human male fertility have not been adequately evaluated [see Use In Specific Populations and Nonclinical Toxicology].
Lactic Acidosis
Lactic acidosis was reported with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid [see Risks Associated With The Combination Treatment Regimen and ADVERSE REACTIONS]. Lactic acidosis is a known adverse reaction of linezolid. Patients who develop recurrent nausea or vomiting should receive immediate medical evaluation, including evaluation of bicarbonate and lactic acid levels, and interruption of linezolid or the entire combination regimen of Pretomanid Tablets, bedaquiline, and linezolid should be considered.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
Important Information On Co-administration Of Pretomanid Tablets In Combination With Bedaquiline And Linezolid [see DOSAGE AND ADMINISTRATION]
- Inform the patient or caregiver that Pretomanid Tablets administered as a combination regimen with bedaquiline and linezolid would be useful only in adult patients with TB resistant to isoniazid, rifamycins, a fluoroquinolone and a second line injectable antibacterial drug or TB resistant to isoniazid and rifampin, who are treatment-intolerant or nonresponsive to standard therapy. This regimen is not indicated for treatment in patients with latent infection or extra-pulmonary infection due to M. tuberculosis, drug-sensitive TB, TB resistant to isoniazid and rifampin who are responsive to standard therapy and not treatment- intolerant, or who have TB with known resistance to any component of the regimen (Pretomanid Tablets, bedaquiline, or linezolid).
- Instruct the patient or caregiver that the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid must be administered by directly observed therapy (DOT).
- Inform patients of safety concerns associated with linezolid and bedaquiline and advise the patient or their caregiver to read the Medication Guide for bedaquiline.
Serious Adverse Reactions
Advise patients that the following serious adverse reactions can occur with the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid: liver enzyme abnormalities, myelosuppression including anemia, peripheral and optic neuropathy, and cardiac rhythm abnormalities [see WARNINGS AND PRECAUTIONS].
Additional serious adverse reactions can occur with the use of linezolid, including serotonin syndrome, lactic acidosis, and convulsions. Refer to the prescribing information for linezolid for additional counseling information for these serious adverse reactions.
Peripheral And Optic Neuropathy
Advise patients to promptly inform their physician if they experience changes in vision during linezolid therapy. Monitor visual function in all patients receiving linezolid. Counsel patients to obtain prompt ophthalmological evaluation if the patient experiences symptoms of visual impairment [see WARNINGS AND PRECAUTIONS].
Interruption Of Linezolid Dosing To Manage Linezolid Adverse Reactions
Counsel patients that linezolid dosing may be modified or interrupted during the therapy to manage the known linezolid adverse reactions of myelosuppression, peripheral neuropathy, and optic neuropathy [see DOSAGE AND ADMINISTRATION section and ADVERSE REACTIONS].
Compliance With Treatment
Inform patients that Pretomanid Tablets must be taken as part of a combination regimen with bedaquiline and linezolid. Compliance with the full course of therapy must be emphasized. Advise patients that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed for the full prescribed duration of dosing. Skipping doses other than as directed by a physician or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that their Mycobacterium may develop resistance and the disease will not be treatable by the regimen or other antibacterial drugs in the future.
Important Administration Instructions
- Inform patients to take the regimen with food. Doses of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid missed for safety reasons can be made up at the end of treatment; doses of linezolid alone missed due to linezolid adverse reactions should not be made up. If bedaquiline and/or Pretomanid Tablets are permanently discontinued, the entire combination regimen of Pretomanid Tablets, bedaquiline, and linezolid should be discontinued.
- Advise patients who have difficulty swallowing tablets that Pretomanid Tablets can be crushed and suspended in water at room temperature. Alternately, the tablet can be soaked for 4 to 5 minutes in room temperature water and then the remaining solid crushed [see DOSAGE AND ADMINISTRATION].
Use In Patients With Hepatic Or Renal Impairment
Advise patients to inform their physician if they have a history of liver or kidney problems. The safety and effectiveness of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid in populations with hepatic or renal impairment have not been established.
Use With Alcohol And Other Medications
Advise patients to discuss with their physician the other medications they are taking and other medical conditions before starting treatment with Pretomanid Tablets.
Advise patients to abstain from alcohol, hepatotoxic medications, and herbal products [see DRUG INTERACTIONS].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenesis
No mutagenic or clastogenic effects were detected in conventional genotoxicity studies with pretomanid. A circulating metabolite of pretomanid, M50, was mutagenic in a bacterial reverse mutation assay. No carcinogenic potential was revealed in a 6-month study in transgenic mice where this metabolite was produced. In a 2-year study in rats, there was no evidence of carcinogenic risk.
Mutagenesis
No mutagenic or clastogenic effects were detected in both an in vitro bacterial reverse mutation assay and an in vitro mammalian chromosome aberrations assay using a Chinese hamster ovary cell line. Pretomanid was negative for clastogenicity in a mouse bone marrow micronucleus assay.
A metabolite of pretomanid was mutagenic in a bacterial reverse mutation assay. This metabolite represents approximately 6% of the human exposure (AUC) to pretomanid at the MRHD.
Fertility
In a fertility and general reproduction study in rats, male rats treated orally with pretomanid for 13 to 14 weeks had reduced fertility at 30 mg/kg/day and complete infertility at 100 mg/kg/day (approximately 1 and 2-times the human exposure for a 200 mg dose, respectively). At 100 mg/kg/day, males had testicular atrophy including hypospermia in the epididymal tubules and focal epithelial hyperplasia of the epididymal tubular epithelium. Following a 10-week treatment-free period, these effects were partially reversed in male rats given pretomanid at 30 mg/kg/day but not at 100 mg/kg/day. These effects were associated with increased serum follicle-stimulating hormone and decreased serum inhibin B concentrations. There were no effects of pretomanid in male rats treated for 13 weeks at 10 mg/kg/day (approximately half of the human exposure for a 200 mg dose). Pretomanid did not affect mating behavior in female rats given oral pretomanid at 100 mg/kg/day for two weeks (approximately twice the human exposure).
Testicular toxicity was present in male mice treated orally for 13 weeks at 20 mg/kg/day [approximately equal to the human exposure (AUC) for a 200 mg dose]. There were no adverse testicular effects observed in mice given pretomanid at 6 mg/kg/day (0.2-times the human exposure for a 200 mg dose).
Testicular toxicity was observed in male rats following 7 or 14 days of dosing with oral pretomanid at 100 mg/kg/day (approximately 2-times the human exposure for a 200 mg dose). The effects were partially reversible during a 6-month post treatment recovery period in rats treated with pretomanid for 7 days, but not 14 days.
In a 3-month study, decreased sperm motility and total sperm count, and increased abnormal sperm ratio were noted in sexually mature monkeys given ≥ 150 mg/kg/day (approximately 3 times the human exposure for a 200 mg dose).
Use In Specific Populations
Pregnancy
Risk Summary
There are no studies or available data on pretomanid use in pregnant women to inform any drug-associated risks. There are risks associated with active tuberculosis during pregnancy (see Clinical Considerations). When Pretomanid Tablets are administered in combination with bedaquiline and linezolid, the pregnancy information for bedaquiline and linezolid also applies to this combination regimen. Refer to the bedaquiline and linezolid prescribing information for more information on bedaquiline and linezolid associated risks of use during pregnancy. In animal reproduction studies, there was increased post-implantation loss in the presence of maternal toxicity (reduced bodyweight and feed consumption) with oral administration of pretomanid during organogenesis in rats at doses about 4 times the exposure at the recommended dose in humans. There were no adverse embryo fetal effects in rats or rabbits dosed with oral pretomanid during organogenesis at doses up to approximately 2 times the exposure in humans.
The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the United States general population, the estimated background risks of major birth defects and miscarriage in clinically recognized pregnancies are 2% to 4% and 15% to 20%, respectively.
Clinical Considerations
Disease-Associated Maternal and/or Embryo/Fetal Risk
Active tuberculosis in pregnancy is associated with adverse maternal and neonatal outcomes including maternal anemia, caesarean delivery, preterm birth, low birth weight, birth asphyxia, and perinatal infant death.
Data
Animal Data
In animal reproduction studies, pregnant rats were dosed orally with pretomanid at 10, 30, and 100 mg/kg/day during organogenesis (gestational Days 7 through 17). Rats showed increased post-implantation loss in the presence of maternal toxicity (including reduced body weight and feed consumption) at 100 mg/kg/day, approximately 4 times the exposure in humans for a 200 mg dose on an AUC basis. There were no adverse embryofetal effects in rats dosed with oral pretomanid during organogenesis at doses up to approximately 2 times the exposure in humans. Pregnant rabbits were dosed orally with pretomanid during organogenesis (gestational Days 7 through 19) at 10, 30, and 60 mg/kg/day. No evidence of adverse developmental outcomes was observed when oral doses of pretomanid were administered to dams during organogenesis (gestational Days 7 to 19) at doses up to 60 mg/kg/day (approximately 2 times the exposure in humans for a 200 mg dose on an AUC basis).
In a pre- and postnatal development study, there were no adverse developmental effects in pups of pregnant rats orally dosed with up to 20 mg/kg/day from gestational Day 6 through lactation Day 20. Pups of pregnant females dosed at 60 mg/kg/day (about 2 times the exposure for the 200 mg dose) had lower body weights and a slight delay in the age at which the air-drop righting reflex developed. These effects occurred at a maternally toxic dose (based on maternal weight loss and reduced food consumption).
Lactation
Risk Summary
There is no information regarding the presence of pretomanid in human milk, or its effects on milk production or the breastfed infant. Pretomanid was detected in rat milk (see Data). When a drug is present in animal milk, it is likely that the drug will be present in human milk. Because of the potential for adverse reactions in nursing infants, the developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for Pretomanid Tablets and any potential adverse effects on the breastfed infant from Pretomanid Tablets or from the underlying maternal condition. When Pretomanid Tablets are administered in combination with bedaquiline and linezolid, information on lactation for bedaquiline and linezolid also applies to this combination regimen. Refer to the bedaquiline and linezolid prescribing information for more information on their use during lactation.
Data
Animal Data
In a pre- and postnatal development study in rats treated with pretomanid at doses 0.5 and 2 times the human exposure for a 200 mg dose (AUC) from gestational day 7 through lactation day 20, concentrations in milk on lactation day 14 were 1.4 and 1.6 times higher than the maximum concentration observed in maternal plasma, respectively. The concentration of pretomanid in rat milk does not necessarily predict the concentration of pretomanid in human milk.
Females And Males Of Reproductive Potential
Infertility
Males
Reduced fertility and/or testicular toxicity were observed in male rats and mice treated with oral pretomanid. These effects were associated with hormonal changes including decreased serum inhibin B and increased serum follicle stimulating hormone and luteinizing hormone in rodents [see Nonclinical Toxicology].
Reduced fertility and testicular toxicity cannot be definitively ruled out in male human subjects at this time.
Pediatric Use
Safety and effectiveness of Pretomanid Tablets in pediatric patients have not been established.
Geriatric Use
Clinical studies of the combination regimen of Pretomanid Tablets, bedaquiline, and linezolid did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects.
Hepatic Impairment
The effect of hepatic impairment on the safety, effectiveness, and pharmacokinetics of pretomanid is not known.
Renal Impairment
The effect of renal impairment on the safety, effectiveness, and pharmacokinetics of pretomanid is not known.