Drug Interaction Report

Coadministration with inhibitors of CYP450 2C9 may increase the serum levels and effects of carvedilol. The mechanism is inhibition of CYP450 2C9, one of the primary isoenzymes involved in the metabolism of carvedilol. According to the prescribing information, CYP450 2C9 is thought to be of importance in the O-methylation pathway of S(-)-carvedilol. Further reductions in heart rate or cardiac conduction may occur.

ADJUST DOSING INTERVAL: Food reduces the oral absorption and bioavailability of voriconazole. According to the product labeling, administration of multiple doses of voriconazole with high-fat meals decreased the mean peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) by 34% and 24%, respectively, when the drug is administered as a tablet, and by 58% and 37%, respectively, when administered as the oral suspension.

MANAGEMENT: To ensure maximal oral absorption, voriconazole tablets and oral suspension should be taken at least one hour before or after a meal.