atovaquone

1 INDICATIONS AND USAGE Atovaquone oral suspension is a quinone antimicrobial drug indicated for: • Prevention of Pneumocystis jirovecii pneumonia (PCP) in adults and adolescents aged 13 years and older who cannot tolerate trimethoprim-sulfamethoxazole (TMP-SMX). ( 1.1 ) • Treatment of mild-to-moderate PCP in adults and adolescents aged 13 years and older who cannot tolerate TMP-SMX. ( 1.2 ) Limitations of Use ( 1.3 ): • Treatment of severe PCP (alveolar arterial oxygen diffusion gradient [(A-a)DO 2 ] >45 mm Hg) with atovaquone has not been studied. • The efficacy of atovaquone in subjects who are failing therapy with TMP-SMX has also not been studied. 1.1 Prevention of Pneumocystis jirovecii Pneumonia Atovaquone oral suspension is indicated for the prevention of Pneumocystis jirovecii pneumonia (PCP) in adults and adolescents (aged 13 years and older) who cannot tolerate trimethoprim-sulfamethoxazole (TMP-SMX). 1.2 Treatment of Mild-to-Moderate Pneumocystis jirovecii Pneumonia Atovaquone oral suspension is indicated for the acute oral treatment of mild-to-moderate PCP in adults and adolescents (aged 13 years and older) who cannot tolerate TMP-SMX. 1.3 Limitations of Use Clinical experience with atovaquone oral suspension for the treatment of PCP has been limited to subjects with mild-to-moderate PCP (alveolar-arterial oxygen diffusion gradient [(A-a)DO 2 ] ≤45 mm Hg). Treatment of more severe episodes of PCP with atovaquone oral suspension has not been studied. The efficacy of atovaquone oral suspension in subjects who are failing therapy with TMP-SMX has also not been studied.

2 DOSAGE AND ADMINISTRATION • Prevention of PCP: 1,500 mg (10 mL) once daily with food ( 2.1 ) • Treatment of PCP: 750 mg (5 mL) twice daily with food for 21 days ( 2.2 ) • Supplied in foil pouches and bottles: o Foil Pouch: For a 5 mL dose, take entire contents by mouth either by dispensing into a spoon or cup or directly into the mouth. For a 10 mL dose, take entire contents of two pouches. ( 2.3 ) o Bottle: Shake bottle gently before use. ( 2.3 ) 2.1 Dosage for the Prevention of P. jirovecii Pneumonia The recommended oral dosage is 1,500 mg (10 mL) once daily administered with food. 2.2 Dosage for the Treatment of Mild-to-Moderate P. jirovecii Pneumonia The recommended oral dosage is 750 mg (5 mL) twice daily (total daily dose = 1,500 mg) administered with food for 21 days. 2.3 Important Administration Instructions Administer atovaquone oral suspension with food to avoid low plasma atovaquone concentrations that may limit response to therapy [see Warnings and Precautions ( 5.1 ), Clinical Pharmacology ( 12.3 )]. Atovaquone Oral Suspension Foil Pouch • Open each 5 mL pouch by removing tab at perforation and tear at notch. • For a 5 mL dose, take entire contents either by placing directly into the mouth or by dispensing into a dosing spoon (5 mL) or cup prior to administration by mouth. • For a 10 mL dose, take the entire contents of two pouches. Atovaquone Oral Suspension Bottle Shake bottle gently before administering the recommended dosage.

5 WARNINGS AND PRECAUTIONS • Failure to administer atovaquone oral suspension with food may result in lower plasma atovaquone concentrations and may limit response to therapy. Patients with gastrointestinal disorders may have limited absorption resulting in suboptimal atovaquone concentrations. ( 5.1 ) • Hepatotoxicity: Elevated liver chemistry tests and cases of hepatitis and fatal liver failure have been reported. ( 5.2 ) • Severe Cutaneous Adverse Reactions (SCARs): Cases of SCARs such as Stevens-Johnson Syndrome (SJS) have been reported. SCARs can be life-threatening or fatal. If symptoms or signs of SCARs develop, discontinue atovaquone immediately and institute appropriate therapy. ( 5.3 ) 5.1 Risk of Limited Oral Absorption Absorption of orally administered atovaquone oral suspension is limited but can be significantly increased when the drug is taken with food. Failure to administer atovaquone oral suspension with food may result in lower plasma atovaquone concentrations and may limit response to therapy. Consider therapy with other agents in patients who have difficulty taking atovaquone oral suspension with food or in patients who have gastrointestinal disorders that may limit absorption of oral medications [see Clinical Pharmacology ( 12.3 )]. 5.2 Hepatotoxicity Cases of cholestatic hepatitis, elevated liver enzymes, and fatal liver failure have been reported in patients treated with atovaquone [see Adverse Reactions ( 6.2 )]. If treating patients with severe hepatic impairment, closely monitor patients following administration of atovaquone. 5.3 Severe Cutaneous Adverse Reactions Cases of severe cutaneous adverse reactions (SCARs), including Stevens-Johnson Syndrome (SJS), drug reaction with eosinophilia and systemic symptoms (DRESS), and erythema multiforme (EM) have been reported in patients treated with atovaquone [see Adverse Reactions ( 6.2 )] . SCARs can be life-threatening or fatal. If symptoms or signs of SCARs develop, discontinue atovaquone immediately and institute appropriate therapy. Patients who have developed SCARs with the use of atovaquone must not receive atovaquone [see Contraindications ( 4 )] .

4 CONTRAINDICATIONS Atovaquone oral suspension is contraindicated in patients who develop or have a history of hypersensitivity reactions to atovaquone or any of the components of atovaquone oral suspension [see Warnings and Precautions ( 5.3 ), Adverse Reactions ( 6.2 )] . Known serious allergic/hypersensitivity reaction to atovaquone or any of the components of atovaquone oral suspension. ( 4 )

7 DRUG INTERACTIONS • Concomitant administration of rifampin or rifabutin reduces atovaquone concentrations; concomitant use with atovaquone oral suspension is not recommended. ( 7.1 ) • Concomitant administration of tetracycline reduces atovaquone concentrations; use caution when coadministering. Monitor patients for potential loss of efficacy of atovaquone if coadministration of tetracycline is necessary. ( 7.2 ) • Concomitant administration with metoclopramide reduces atovaquone concentrations; administer concomitantly only if other antiemetics are not available. ( 7.3 ) • Concomitant administration of indinavir reduces indinavir trough concentrations; use caution when coadministering. Monitor patients for potential loss of efficacy of indinavir if coadministration is necessary. ( 7.4 ) 7.1 Rifampin/Rifabutin Concomitant administration of rifampin or rifabutin and atovaquone oral suspension is known to reduce atovaquone concentrations [see Clinical Pharmacology ( 12.3 )] . Concomitant administration of atovaquone oral suspension and rifampin or rifabutin is not recommended. 7.2 Tetracycline Concomitant administration of tetracycline and atovaquone oral suspension has been associated with a reduction in plasma concentrations of atovaquone [see Clinical Pharmacology ( 12.3 )]. Caution should be used when prescribing tetracycline concomitantly with atovaquone oral suspension. Monitor patients for potential loss of efficacy of atovaquone if coadministration is necessary. 7.3 Metoclopramide Metoclopramide may reduce the bioavailability of atovaquone and should be used only if other antiemetics are not available [see Clinical Pharmacology ( 12.3 )]. 7.4 Indinavir Concomitant administration of atovaquone and indinavir did not result in any change in the steady-state AUC and C max of indinavir but resulted in a decrease in the C trough of indinavir [see Clinical Pharmacology ( 12.3 )]. Caution should be exercised when prescribing atovaquone oral suspension with indinavir due to the decrease in trough concentrations of indinavir. Monitor patients for potential loss of efficacy of indinavir if coadministration with atovaquone oral suspension is necessary.

8.1 Pregnancy Risk Summary Available data from postmarketing experience with use of atovaquone in pregnant women are insufficient to identify a drug-associated risk for major birth defects, miscarriage, or adverse maternal or fetal outcomes. Pregnant women with HIV who are infected with PCP are at increased risk of adverse pregnancy outcomes (see Clinical Considerations) . Atovaquone given orally by gavage to pregnant rats and rabbits during organogenesis did not cause fetal malformations at plasma concentrations up to 3 times and 0.5 times, respectively, the estimated human exposure based on steady-state plasma concentrations (see Data) . 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 U.S. general population, the background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk: Pregnant women with HIV who are infected with PCP are at increased risk of severe illness and maternal death associated with PCP compared with non-pregnant women. Data Animal Data: Atovaquone administered in oral doses of 250, 500, and 1,000 mg/kg/day to pregnant rats during organogenesis (Gestation Day [GD] 6 to GD15) did not cause maternal or embryo-fetal toxicity at doses up to 1,000 mg/kg/day corresponding to maternal plasma concentrations approximately 3 times the estimated human exposure during the treatment of PCP based on steady-state plasma concentrations. In pregnant rabbits, atovaquone administered in oral doses of 300, 600, and 1,200 mg/kg/day during organogenesis (GD6 to GD18) caused decreased fetal body length at a maternally toxic dose of 1,200 mg/kg/day corresponding to a plasma concentration that is approximately 0.5 times the estimated human exposure based on steady-state plasma concentrations. In a pre- and post-natal study in rats, atovaquone administered in oral doses of 250, 500, and 1,000 mg/kg/day from GD15 until Lactation Day (LD) 20 did not impair the growth or developmental effects in first generation offspring at doses up to 1,000 mg/kg/day corresponding to approximately 3 times the estimated human exposure based on steady-state plasma concentrations during the treatment of PCP. Atovaquone crossed the placenta and was present in fetal rat and rabbit tissue.

6 ADVERSE REACTIONS The following adverse reactions are discussed in another section of the labeling: • Hepatotoxicity [see Warnings and Precautions ( 5.2 )]. • Severe Cutaneous Adverse Reactions [see Warnings and Precautions ( 5.3 )]. • PCP Prevention: The most frequent adverse reactions (≥25% that required discontinuation) were diarrhea, rash, headache, nausea, and fever. ( 6.1 ) • PCP Treatment: The most frequent adverse reactions (≥14% that required discontinuation) were rash (including maculopapular), nausea, diarrhea, headache, vomiting, and fever. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Glenmark Pharmaceuticals Inc., USA at 1 (888) 721-7115 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Additionally, because many subjects who participated in clinical trials with atovaquone had complications of advanced human immunodeficiency virus (HIV) disease, it was often difficult to distinguish adverse reactions caused by atovaquone from those caused by underlying medical conditions. PCP Prevention Trials In two clinical trials, atovaquone oral suspension was compared with dapsone or aerosolized pentamidine in HIV-1-infected adolescent (13 to 18 years) and adult subjects at risk of PCP (CD4 count <200 cells/mm 3 or a prior episode of PCP) and unable to tolerate TMP-SMX. Dapsone Comparative Trial: In the dapsone comparative trial (n = 1,057), the majority of subjects were white (64%), male (88%), and receiving prophylaxis for PCP at randomization (73%); the mean age was 38 years. Subjects received atovaquone oral suspension 1,500 mg once daily (n = 536) or dapsone 100 mg once daily (n = 521); median durations of exposure were 6.7 and 6.5 months, respectively. Adverse reaction data were collected only for adverse reactions requiring discontinuation of treatment, which occurred at similar frequencies in subjects treated with atovaquone oral suspension or dapsone (Table 1). Among subjects taking neither dapsone nor atovaquone at enrollment (n = 487), adverse reactions requiring discontinuation of treatment occurred in 43% of subjects treated with dapsone and 20% of subjects treated with atovaquone oral suspension. Gastrointestinal adverse reactions (nausea, diarrhea, and vomiting) were more frequently reported in subjects treated with atovaquone oral suspension (Table 1). Table 1. Percentage (>2%) of Subjects with Selected Adverse Reactions Requiring Discontinuation of Treatment in the Dapsone Comparative PCP Prevention Trial Adverse Reaction All Subjects Atovaquone Oral Suspension 1,500 mg/day (n = 536) % Dapsone 100 mg/day (n = 521) % Rash 6.3 8.8 Nausea 4.1 0.6 Diarrhea 3.2 0.2 Vomiting 2.2 0.6 Aerosolized Pentamidine Comparative Trial: In the aerosolized pentamidine comparative trial (n = 549), the majority of subjects were white (79%), male (92%), and were primary prophylaxis patients at enrollment (58%); the mean age was 38 years. Subjects received atovaquone oral suspension once daily at a dose of 750 mg (n = 188) or 1,500 mg (n = 175) or received aerosolized pentamidine 300 mg every 4 weeks (n = 186); the median durations of exposure were 6.2, 6, and 7.8 months, respectively. Table 2 summarizes the clinical adverse reactions reported by ≥20% of the subjects receiving either the 1,500-mg dose of atovaquone oral suspension or aerosolized pentamidine. Rash occurred more often in subjects treated with atovaquone oral suspension (46%) than in subjects treated with aerosolized pentamidine (28%). Treatment‑limiting adverse reactions occurred in 25% of subjects treated with atovaquone oral suspension 1,500 mg once daily and in 7% of subjects treated with aerosolized pentamidine. The most frequent adverse reactions requiring di…