Drug Interaction Report

MONITOR: Coadministration with potent inhibitors of uridine diphosphate glucuronosyltransferase (UGT) may increase the peak plasma concentration (Cmax) and systemic exposure (AUC) of dihydroartemisinin (DHA), an active metabolite of artesunate and substrate of UGT 1A9 or 2B7. Increased exposure to artesunate may increase the risk of adverse effects such as anemia, increased liver transaminases, thrombocytopenia, hyperbilirubinemia, acute renal failure, and leukocytosis.

MANAGEMENT: Monitoring for adverse reactions is recommended if artesunate is coadministered with potent UGT inhibitors. Dosage adjustments or alternative treatments may be required based on clinical response and tolerance.

ADJUST DOSING INTERVAL: Administration of atazanavir with food enhances oral bioavailability and reduces pharmacokinetic variability. According to the manufacturer, administration with a light meal increased the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of a single 400 mg dose of atazanavir by 57% and 70%, respectively, relative to the fasting state. Administration with a high-fat meal resulted in a mean increase of 35% in atazanavir AUC and no change in Cmax compared to fasting. The coefficient of variation of AUC and Cmax decreased by approximately one-half when given with either a light or high-fat meal compared to the fasting state.

MANAGEMENT: To ensure maximal oral absorption, atazanavir should be administered with or immediately after a meal.