Drug Interactions between atazanavir and Relyvrio

ADJUST DOSING INTERVAL: Coadministration with a high-fat meal may reduce the rate and extent of absorption of sodium phenylbutyrate. When a single 3 g-1 g dose of sodium phenylbutyrate-taurursodiol (sodium phenylbutyrate-ursodoxicoltaurine) was administered to healthy volunteers in the presence of a high-fat, high-calorie meal (approximately 800 to 1000 calories; 500 to 600 calories from fat, 250 calories from carbohydrate, 150 calories from protein), sodium phenylbutyrate peak plasma concentration (Cmax) decreased by 75% and systemic exposure (AUC) decreased by 55%. The Cmax for taurursodiol was not significantly affected, but AUC was increased by 46%. The clinical significance of these changes has not been established. In premarketing studies, patients were advised to take the drug before a meal.

MANAGEMENT: The prescribing information recommends administration of sodium phenylbutyrate-taurursodiol before a meal or snack, particularly in patients of low body weight (less than 70 kg).

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.