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# Atovaquone ## Overview Atovaquone is an antiprotozoal agent. ## Primary Indications * **Prevention and treatment of *Pneumocystis jirovecii* pneumonia (PCP)** in patients with HIV/AIDS who are intolerant to trimethoprim-sulfamethoxazole. * **Treatment of acute *Pneumocystis jirovecii* pneumonia (PCP)** in patients with HIV/AIDS who are intolerant to trimethoprim-sulfamethoxazole. * **Prevention of PCP** in patients with HIV/AIDS. * **Treatment of toxoplasmosis** in combination with other agents for patients intolerant to sulfonamides. ## Adult Dosing **PCP Prophylaxis:** * 1500 mg orally once daily. **PCP Treatment (mild to moderate):** * 1500 mg orally once daily for 21 days. **Toxoplasmosis Treatment (in combination):** * 750 mg orally twice daily, in combination with pyrimethamine and leucovorin, for 4-6 weeks. ## Pediatric Dosing Dosing in pediatric patients is not well-established and depends on specific indication and patient weight. Consult specialized pediatric guidelines or a pediatric infectious disease specialist. ## Dose Adjustments No dose adjustments are typically required for renal or hepatic impairment, but caution is advised in severe cases. ## Contraindications * Known hypersensitivity to atovaquone. ## Adverse Effects Common adverse effects include rash, nausea, vomiting, diarrhea, headache, and insomnia. Less common but serious adverse effects include Stevens-Johnson syndrome, toxic epidermal necrolysis, and liver enzyme elevations. ## Key Drug Interactions * **Cholestyramine and rifampin:** Can significantly decrease atovaquone plasma concentrations. Avoid concurrent use. * **Metoclopramide:** May decrease atovaquone absorption. * **Zidovudine:** Increased risk of zidovudine toxicity (anemia, neutropenia). Monitor blood counts. ## Monitoring * Monitor for clinical signs and symptoms of PCP or toxoplasmosis. * Monitor liver function tests in patients with pre-existing liver disease or receiving concurrent hepatotoxic agents. * Monitor blood counts if used concurrently with zidovudine. ## Clinical Pearls * Atovaquone suspension should be taken with food to enhance absorption. * Absorption is variable and dose-dependent. * The efficacy of atovaquone for PCP prophylaxis in patients with CD4 counts < 200 cells/mm³ is less established than trimethoprim-sulfamethoxazole. *** **Disclaimer:** This information is intended for educational purposes only and does not substitute for professional medical advice. Always consult the most current prescribing information and guidelines for definitive patient management decisions.