Atovaquone Disease Interactions

Oral bioavailability of atovaquone is limited under fasting conditions, but is increased approximately two-fold when administered with food. Patients with gastrointestinal disorders or eating difficulties may be more likely to have impaired absorption and, consequently, subtherapeutic levels of the drug. Alternative parenteral treatment should be considered for patients unable to achieve adequate plasma concentrations of atovaquone with oral administration.

Atovaquone may cause elevated liver function tests. In clinical trials, elevated serum alkaline phosphatase concentrations (> 2.5 times the upper limit of normal, or ULN) were reported in approximately 8% of patients, and elevations in serum ALT and AST (> 5 times ULN) were reported in 6% and 4% of patients, respectively. Increases in serum bilirubin has occurred rarely. Atovaquone also may undergo limited metabolism by the liver. Therapy with atovaquone should be administered cautiously in patients with severe hepatic impairment. Liver function tests should be performed periodically, and therapy withdrawn if significant elevations develop.