Intramuscular Pharmacokinetics of Naltrexone in the African Green Monkey (Chlorocebus aethiops sabeus)
Abstract:
The pharmacokinetics of intramuscular naltrexone human equivalent doses (HEDs) of 2, 10, and 20 mg were evaluated in adult male African green monkeys.Strong dose-linearity was observed between the injected naltrexone dose and plasma concentration maximum (Cmax). Absorption was rapid, with time to maximum concentration (Tmax) approximating 14 minutes for the 10 and 20 mg HEDs. Intramuscular administration of naltrexone in this laboratory non-human primate model exhibited orderly and predictable plasma kinetics. The inclusion of 10 and 20 mg HEDs allows for confident predictions of plasma levels at a bolus intramuscular dose above those commonly administered but potentially required for severe opioid exposure.