Drug Interaction Report

MONITOR: Coadministration with inhibitors of organic anion transporting polypeptides (OATP) 1B1 and/or 1B3 may increase the plasma concentrations and effects of momelotinib, which is a substrate of these hepatic uptake transporters. In a phase I study, coadministration of momelotinib (200 mg) with a single dose of the OATP1B1/1B3 inhibitor rifampin (600 mg) increased the peak plasma concentration (Cmax) and systemic exposure (AUC) of momelotinib by 40% and 57%, respectively. The Cmax and AUC of the active metabolite of momelotinib, M21, was also increased, by 6% and 12%, respectively.

MANAGEMENT: Caution is advised if momelotinib is used in combination with inhibitors of OATP1B1 and/or 1B3. Dosage adjustments of momelotinib may be required. Patients should be advised to report any momelotinib-related adverse reactions such as bacterial or viral infection, thrombocytopenia, neutropenia, hepatotoxicity, thrombosis, and adverse cardiovascular events.

ADJUST DOSING INTERVAL: Food may significantly increase the oral bioavailability of some formulations of abiraterone acetate. Compared to administration in the fasted state, abiraterone peak plasma concentration (Cmax) and systemic exposure (AUC) were approximately 7- and 5-fold higher, respectively, when a single dose of abiraterone acetate was administered with a low-fat meal (7% fat; 300 calories) and approximately 17- and 10-fold higher, respectively, when it was administered with a high-fat meal (57% fat; 825 calories). Given the normal variation in the content and composition of meals, taking abiraterone acetate with meals has the potential to result in increased and highly variable exposures. The safety of these increased exposures during multiple dosing has not been assessed. However, the abiraterone acetate 125 mg tablet, commonly marketed as Yonsa, was found to have an approximately 6.5-fold higher Cmax and 4.4-fold higher AUC when a single dose of 500 mg (4 tablets) was administered with a high-fat meal (56% - 60% fat, 900 - 1000 calories) compared to overnight fasting in healthy volunteers. These differences were not considered clinically significant for this formulation.

MANAGEMENT: Some formulations of abiraterone acetate must be taken on an empty stomach. No food should be consumed for at least two hours before and one hour after the abiraterone acetate dose. However, the abiraterone acetate 125 mg tablet, commonly marketed as Yonsa, can be taken with or without food. The manufacturer's product labeling should be consulted for specific guidance.