Drug Interactions between amprenavir and Hetlioz LQ

GENERALLY AVOID: Administration with a high-fat meal may decrease the oral bioavailability of amprenavir. The mechanism is unknown. In healthy volunteers, consumption of a standardized high-fat meal decreased the peak plasma concentration (Cmax) and area under the concentration-time curve (AUC) of amprenavir (1200 mg single oral dose) by 36% and 21%, respectively, compared to administration in the fasted state. The time to reach Cmax (Tmax) was increased 44% following a high-fat meal.

Grapefruit juice does not appear to significantly affect the pharmacokinetics of amprenavir. In 12 healthy volunteers, administration with grapefruit juice (200 mL) decreased the mean peak plasma concentration (Cmax) of amprenavir (1200 mg single oral dose) by 22% compared to water. The median time to reach Cmax (Tmax) was prolonged from 0.75 to 1.13 hours. These pharmacokinetic changes are not thought to be clinically significant, since antiretroviral response is more closely associated with systemic exposure (AUC) and trough plasma concentration (Cmin), which were not affected in the study.

MANAGEMENT: Amprenavir may be taken with or without food, but should not be taken with a high-fat meal.

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

ADJUST DOSING INTERVAL: Food may delay the absorption and onset of action of tasimelteon. According to the product labeling, administration of tasimelteon with a high-fat meal decreased peak plasma concentration (Cmax) by 44% and delayed the median time to reach Cmax by approximately 1.75 hours compared to administration in the fasted state.

MONITOR: Smoking induces CYP450 1A2 and may reduce the plasma concentrations of tasimelteon, which is metabolized by the isoenzyme. According to the product labeling, tasimelteon systemic exposure was approximately 40% lower in smokers than in nonsmokers.

MANAGEMENT: Patients receiving tasimelteon should be advised to avoid or limit consumption of alcohol. Tasimelteon should be taken without food. Patients who smoke may have a reduced therapeutic response to tasimelteon.