Drug Interactions between rifapentine and zaleplon

ADJUST DOSING INTERVAL: Administration with food may increase the oral bioavailability of rifapentine and reduce the incidence of gastrointestinal adverse events. Administration with a high fat meal typically increases rifapentine's maximum concentration (Cmax) and systemic exposure (AUC) by approximately 40% to 50% over that observed when rifapentine is administered under fasting conditions. Rifapentine is often prescribed in combination with isoniazid. When single doses of rifapentine (900 mg) and isoniazid (900 mg) were administered with a low fat, high carbohydrate breakfast, the Cmax and AUC of rifapentine increased by 47% and 51%, respectively. On the other hand, isoniazid's Cmax and AUC decreased by 46% and 23%, respectively.

MANAGEMENT: Products containing oral rifapentine as the sole ingredient recommend administration with a meal to increase bioavailability and reduce the occurrence of gastrointestinal upset, nausea, and/or vomiting. Consultation of product labeling for combination products and/or relevant guidelines may be helpful if rifapentine is combined with a medication that is typically taken on an empty stomach.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of zaleplon. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

ADJUST DOSING INTERVAL: Administration of zaleplon with a high-fat or heavy meal may delay the onset of hypnotic effects. In healthy adult subjects, administration of zaleplon with a high-fat meal resulted in a 2-hour delay in the time to reach peak plasma drug concentration (Tmax) and a 35% reduction in the peak plasma drug concentration (Cmax) compared to fasting. Zaleplon systemic exposure (AUC) and elimination half-life were not significantly affected.

MANAGEMENT: Patients receiving zaleplon should be advised to avoid the consumption of alcohol. For faster sleep onset, zaleplon should not be administered with or immediately after a high-fat or heavy meal.