Drug Interaction Report

GENERALLY AVOID: Coadministration with potent inducers of CYP450 3A4 may significantly decrease the plasma concentrations of netupitant. When a single 300 mg-0.5 mg dose of netupitant-palonosetron was administered following 600 mg once daily administration of the potent CYP450 3A4 inducer rifampin for 17 days, mean netupitant peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 62% and 82%, respectively, while mean Cmax and AUC of palonosetron decreased by 15% and 19%, respectively.

MANAGEMENT: Concomitant use of netupitant or its prodrug, fosnetupitant, should generally be avoided during chronic administration of potent CYP450 3A4 inducers due to the potential for reduced efficacy of netupitant.

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.