Atovaquone dosage

The effect of rifabutin is less than rifampicin, and the authors of the above report suggested that no atovaquone dosage adjustment is needed. However, in the UK, the manufacturer of atovaquone still considers that rifabutin use could result in subtherapeutic atovaquone levels in some patients, and they also advise against the concurrent use of this combination. ... 

Malarone is generally well tolerated. Adverse effects include abdominal pain, nausea, vomiting, diarrhea, headache, and rash, and these are more common with the higher dosage required for treatment. Reversible elevations in liver enzymes have been reported. The safety of atovaquone in pregnancy is unknown. Plasma concentrations of atovaquone are decreased about 50% by co-administration of tetracycline or rifampin. 

Of 39 patients who had bone marrow transplants and who were randomized to receive either co-trimoxazole or atovaquone as prophylaxis in an open-label trial, eight taking co-trimoxazole withdrew because of presumed drug reactions, although in five of these the reported neutropenia and thrombocytopenia could have been a consequence of transplantation itself or of other drugs (2). None of 16 patients treated with atovaquone withdrew. This rate of reported adverse effects with co-trimoxazole is higher than usually reported in clinical practice with prophylactic dosages. 

Atovaquone 62.5 mg/proguanil 25 mg (Malarone), pediatric dosage strength. 

This study shows there is no important pharmacokinetic interaction between atovaquone and co-trimoxazole. No dosage adjustments of either drug would be required on eoncurrent use. 

In a pharmacokinetic study in HIV-positive subjects designed to determine the dose of atovaquone suspension that would achieve specific steady-state plasma levels, administration with high-fat food increased the bioavailability of atovaquone by 1.4-fold when compared with the fasted state. In another similar study, administration of atovaquone suspension with food (23 g of fat) increased average steady-state levels by 1.3-fold to 1.7-fold with different dosage regimens (using 500 mg to 1.5 g of atovaquone. ... 

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