Drug Interaction Report

MONITOR: Coadministration of momelotinib may increase the plasma concentrations and effects of drugs that are substrates of the P-glycoprotein (P-gp) efflux transporter. The proposed mechanism is increased exposure of the P-gp substrate due to inhibition of intestinal P-gp efflux transporter. However, clinical data are not available.

MANAGEMENT: Caution is recommended with the concomitant use of momelotinib and P-gp substrates, particularly those with a narrow therapeutic index. Dosage adjustments as well as clinical and laboratory monitoring should be considered whenever momelotinib is added to or withdrawn from therapy with these drugs. Individual product labeling for the coadministered drug may also be consulted for specific guidance.

Food enhances the oral absorption and bioavailability of tenofovir, the active entity of tenofovir disoproxil fumarate. According to the product labeling, administration of the drug following a high-fat meal increased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of tenofovir by approximately 14% and 40%, respectively, compared to administration in the fasting state. However, administration with a light meal did not significantly affect the pharmacokinetics of tenofovir compared to administration in the fasting state. Food delays the time to reach tenofovir Cmax by approximately 1 hour. Tenofovir disoproxil fumarate may be administered without regard to meals.