Drug Interaction Report

CONTRAINDICATED: Coadministration with potent inhibitors of CYP450 3A4 may significantly increase the plasma concentrations of ticagrelor, which is primarily metabolized by the isoenzyme. In healthy volunteers, administration of ticagrelor in combination with the potent CYP450 3A4 inhibitor ketoconazole resulted in increased ticagrelor peak plasma concentration (Cmax) and systemic exposure (AUC) by 2.4-fold and 7.3-fold, respectively, and reduced Cmax and AUC of the active metabolite by 89% and 56%, respectively.

MANAGEMENT: Concomitant use of ticagrelor with potent CYP450 3A4 inhibitors is considered contraindicated by some foreign authorities. The U.S. labeling for ticagrelor recommends avoiding use with potent CYP450 3A4 inhibitors. Labeling for itraconazole, a potent CYP450 3A4 inhibitor, specifically contraindicates use with ticagrelor during and for 2 weeks after treatment with itraconazole.

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.