Drug Interaction Report

MONITOR: Coadministration with inhibitors of CYP450 3A4 may increase the plasma concentrations of zolpidem, which is partially metabolized by the isoenzyme. When a single 5 mg dose of zolpidem was administered to 12 healthy study subjects following treatment with the potent CYP450 3A4 inhibitor ketoconazole (200 mg twice daily for 2 days), zolpidem peak plasma concentration (Cmax) and systemic exposure (AUC) increased by 35% and 67%, respectively. Increased sedation and other pharmacodynamic effects were noted.

MANAGEMENT: Caution is advised when zolpidem is used with CYP450 3A4 inhibitors. Patients should be advised to avoid driving, operating machinery, or engaging in potentially hazardous activities requiring mental alertness and motor coordination until they know how the medications affect them, and to notify their physician if they experience excessive somnolence or dizziness.

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

ADJUST DOSING INTERVAL: Administration of zolpidem with food may delay the onset of hypnotic effects. In 30 healthy subjects, administration of zolpidem 20 minutes after a meal resulted in decreased mean peak plasma drug concentration (Cmax) and area under the concentration-time curve (AUC) by 25% and 15%, respectively, compared to fasting. The time to reach peak plasma drug concentration (Tmax) was prolonged by 60%, from 1.4 to 2.2 hours.

MANAGEMENT: Patients receiving zolpidem should be advised to avoid the consumption of alcohol. For faster sleep onset, zolpidem should not be administered with or immediately after a meal.