Atovaquone

Warnings and Precautions, Severe Cutaneous Adverse Reactions (5.3) 3/2026 Warnings and Precautions, Severe Cutaneous Adverse Reactions ( 5.3 ) 3/2026

1 INDICATIONS AND USAGE 1 INDICATIONS AND USAGE ------------------- 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 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 has not been studied. The efficacy of atovaquone in subjects who are failing therapy with TMP-SMX has also not been studied.

2 DOSAGE AND ADMINISTRATION 2 DOSAGE AND ADMINISTRATION 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 (Section 5.1), Clinical Pharmacology (Section 12.3)]. Shake gently before administering the recommended dosage. --------------- 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 unit dose cups: Shake 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)]. Shake bottle gently before administering the recommended dosage.

3 DOSAGE FORMS AND STRENGTHS 3 DOSAGE FORMS AND STRENGTHS Atovaquone oral suspension, USP is an opaque yellow, artificial mixed berry-flavored, oral suspension containing 750 mg of atovaquone USP in 5 mL. Atovaquone oral suspension, USP is supplied in 5 mL unit dose cups. --------------- DOSAGE FORMS AND STRENGTHS ------------- Oral suspension: 750 mg per 5 mL (3)

4 CONTRAINDICATIONS 4 CONTRAINDICATIONS Atovaquone oral suspension is contraindicated in patients who develop or have a history of hypersensitivity reactions (e.g., angioedema, bronchospasm, throat tightness, urticaria) to atovaquone or any of the components of atovaquone oral suspension. ---------------------- CONTRAINDICATIONS ----------------------- Known serious allergic/hypersensitivity reaction (e.g., angioedema, bronchospasm, throat tightness, urticaria) to atovaquone or any of the components of atovaquone oral suspension. (4)

6 ADVERSE REACTIONS 6 ADVERSE REACTIONS The following adverse reaction is discussed in another section of the labeling: Hepatotoxicity [see Warnings and Precautions (Section 5.2)]. 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 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 discontinuation of dosing in the group receiving atovaquone oral suspension 1,500 mg once daily were rash (6%), diarrhea (4%), and nausea (3%). The most frequent adverse reaction requiring discontinuation of dosing in the group receiving aerosolized pentamidine was bronchospasm (2%). Table 2. Percentage (≥ 20%) of Subjects with Selected Adverse Reactions in the Aerosolized Pentamidine Comparative PCP Prevention Trial Adverse Reaction Atovaquone Oral Suspension 1,500 mg/day (n = 175) % Aerosolized Pentamidine (n = 186) % Diarrhea 42 35 Rash 39 28 Headache 28 22 Nausea 26 23 Fever 25 18 Rhinitis 24 17 Other reactions occurring in ≥10% of subjects receiving the recommended dose of atovaquone oral suspension (1,500 mg once daily) included vomiting, sweating, flu syndrome, sinusitis, pruritus, insomnia, depression, and myalgia. PCP Treatment Trials Safety information is presented from 2 clinical efficacy trials of the atovaquone tablet formulation: 1) a randomized, double-blind trial comparing atovaquone tablets with MP-SMX in subjects with acquired immunodeficiency syndrome (AIDS) and mild-to- moderate PCP [(A-a)DO2] ≤ 45 mmHg and PaO2 ≥ 60 mmHg on room air; 2) a randomized, open-label trial comparing atovaquone tablets with intravenous (IV) pentamidine isethionate in subjects with mild-to-moderate PCP who could not tolerate trimethoprim or sulfa antimicrobials. TMP-SMX Comparative Trial: In the TMP-SMX comparative trial (n = 408), the majority of subjects were white (66%) and male (95%); the mean age was 36 years. Subjects received atovaquone 750 mg (three 250 mg tablets) 3 times daily for 21 days or TMP 320 mg plus SMX 1,600 mg 3 …

7 DRUG INTERACTIONS 7 DRUG INTERACTIONS 7.1 Rifampin/Rifabutin Concomitant administration of rifampin or rifabutin and atovaquone oral suspension is known to reduce atovaquone concentrations [see Clinical Pharmacology (Section 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 concen- trations of atovaquone [see Clinical Pharmacology (Section 12.3)] . Caution should be used when prescribing tetracycline concomitant- ly 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 (Section 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 (Section 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. -------------------- 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 co-administering. Monitor patients for potential loss of efficacy of atovaquone if co-administration 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 co-administering. Monitor patients for potential loss of efficacy of indinavir if co-administration 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 co-administration 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 co-administration with atovaquone oral suspension is necessary.

8 USE IN SPECIFIC POPULATIONS 8 USE IN SPECIFIC POPULATIONS 8.1 Pregnancy Risk Summary Available data from post marketing 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 (Gesta- tion 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 mg, 600 mg, 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 mg, 500 mg, 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. 8.2 Lactation Risk Summary The Centers for Disease Control and Prevention recommend that HIV-1-infected mothers not breastfeed their infants to avoid risking postnatal transmission of HIV-1. There are no data on the presence of atovaquone in human milk, the effects on the breastfed child, or the effects on milk production. Atovaquone was detected in rat milk when lactating rats were administered oral atovaquone (see Data). When a drug is present in animal milk, it is likely the drug will be present in human milk. Because of the potential for HIV-1 transmission to HIV-negative infants, instruct mothers with HIV-1 not to breastfeed if they are taking atovaquone oral suspension for the prevention or treatment of PCP. Data In a rat study with doses of 10 mg and 250 mg/kg given orally by gavage on postpartum Day 11, atovaquone concentrations in the milk were 30% of the concurrent atovaquone concentrations in the maternal plasma at both doses. The concentration of drug in animal milk does not necessarily predict the concentration of drug in human milk. 8.4 Pediatric Use Evidence of safety and effectiveness in pediatric patients (aged 12 years and younger) has not been established. In a trial of atovaquone oral suspension administered once daily with food for 12 days to 27 HIV-1-infected, asymptomatic infants and children aged between 1- month and 13 years, the pharmacokinetics of atovaquone were age-depe …

12.1 Mechanism of Action Atovaquone is a quinone antimicrobial drug [see Clinical Pharmacology ( 12.4 )] .

11 DESCRIPTION Atovaquone Oral Suspension, USP is a quinone antimicrobial drug. The chemical name of atovaquone USP is trans -2-[4-(4-chlorophenyl) cyclohexyl]-3-hydroxy-1,4-naphthalenedione. Atovaquone USP is a yellow crystalline powder that is freely soluble in N-methyl-2-pyrrolidone and in tetrahydrofuran; soluble in chloroform; sparingly soluble in acetone and dimethyl sulfoxide; slightly soluble in octanol, ethyl acetate and polyethylene glycol 200; very slightly soluble in 0.1N sodium hydroxide; insoluble in water. It has a molecular weight of 366.84 and the molecular formula C 22 H 19 ClO 3 . The compound has the following structural formula: Atovaquone Oral Suspension, USP is a formulation of micro-fine particles of atovaquone USP. Each 5 mL of Atovaquone Oral Suspension, USP contains 750 mg of atovaquone USP and the inactive ingredients benzyl alcohol, citric acid monohydrate, hypromellose, poloxamer 188, purified water, saccharin sodium, trisodium citrate dihydrate, tutti frutti flavor and xanthan gum. structure

10 OVERDOSAGE 10 OVERDOSAGE Overdoses up to 31,500 mg of atovaquone have been reported. In one such patient who also took an unspecified dose of dapsone, methemoglobinemia occurred. Rash has also been reported after overdose. There is no known antidote for atovaquone, and it is currently unknown if atovaquone is dialyzable.

16 HOW SUPPLIED/STORAGE AND HANDLING Atovaquone oral suspension USP (bright yellow, tutti frutti flavored) containing 750 mg atovaquone per 5 mL is available in: NDC 0121-0956-08: 210 mL bottle with child-resistant cap. NDC 0121-1016-05: 5 mL unit dose cup NDC 0121-1016-18: Case contains 18 unit dose cups of 5 mL (0121-1016-05) packaged in 3 trays of 6 unit dose cups each. NDC 0121-1016-42: Case contains 42 unit dose cups of 5 mL (0121-1016-05) packaged in 7 trays of 6 unit dose cups each. Store at 15°C to 25°C (59°F to 77°F). Do not freeze. Dispense in tight container as defined in USP.