Fentanyl pharmacokinetics in awake volunteers

A single intravenous dose of fentanyl (either 2 or 4 micrograms/kg body weight) was given to 13 healthy, young volunteer subjects. Serum fentanyl concentration decreased in a triexponential pattern. The terminal half-times were 750 and 853 minutes, respectively. A three-compartment, open, mammillary model is proposed for fentanyl kinetics.