Drug Interaction Report

GENERALLY AVOID: Concurrent acute use of barbiturates and ethanol may result in additive CNS effects, including impaired coordination, sedation, and death. Tolerance of these agents may occur with chronic use. The mechanism is related to inhibition of microsomal enzymes acutely and induction of hepatic microsomal enzymes chronically.

MANAGEMENT: The combination of ethanol and barbiturates should be avoided.

ADJUST DOSING INTERVAL: Exenatide slows gastric emptying and may reduce the extent and rate of absorption of concomitantly administered oral medications. When acetaminophen 1000 mg was administered simultaneously with exenatide 10 mcg and also one hour, 2 hours, and 4 hours after exenatide injection, acetaminophen systemic exposure (AUC) was decreased by 21%, 23%, 24%, and 14%, respectively; peak plasma concentration (Cmax) was decreased by 37%, 56%, 54%, and 41%, respectively; and time to peak plasma concentration (Tmax) was increased from 0.6 hours in the control period to 0.9 hours, 4.2 hours, 3.3 hours, and 1.6 hours, respectively. These values were not significantly changed when acetaminophen was given one hour before exenatide injection.

MANAGEMENT: Concomitantly administered oral medications that are dependent on threshold concentrations for efficacy (e.g., antibiotics, contraceptives) or that require rapid gastrointestinal absorption (e.g., hypnotics, pain medications) should be administered at least 1 hour before exenatide. If such medications are to be administered with food, patients should be advised to take them with a meal or snack when exenatide is not administered.