Drug Interactions between chlorzoxazone and Triumeq PD

GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents such as chlorzoxazone. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills. In addition, in one small study, watercress was reported to increase chlorzoxazone peak concentrations, AUC, and half-life. The proposed mechanism is inhibition of CYP450 2E1 metabolism. The clinical significance is unknown.

MANAGEMENT: Patients receiving chlorzoxazone should be 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 chlorzoxazone affects them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities. Watercress should be avoided if an interaction is suspected; e.g., excess sedation, nausea, or headache occurs.

Food increases the extent of absorption and slows the rate of absorption of dolutegravir. When administered with a low-, moderate- or high-fat meal, dolutegravir peak plasma concentration (Cmax) increased by 46%, 52% and 67%, systemic exposure (AUC) increased by 33%, 41% and 66%, and time to reach Cmax (Tmax) increased from 2 hours to 3, 4 and 5 hours, respectively, compared to administration under fasted conditions. Dolutegravir may be taken with or without food.