Drug Interaction Report

Based on in vitro data, coadministration with potent inhibitors of CYP450 3A4 and/or 2C19 may be expected to increase the plasma concentrations of ambrisentan, which is a substrate of these isoenzymes. However, administration with ketoconazole (potent CYP450 3A4 inhibitor) or omeprazole (potent CYP450 2C19 inhibitor) did not result in clinically relevant changes in ambrisentan exposure.

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.

MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.