Metabolism and Pharmacokinetics

Droperidol is biotransformed in the liver into two primary metabolites, ^[719] and its plasma decay can be described by a two-compartment model. Its pharmacokinetics^[22] is shown in Table 10-1 . Clearance of droperidol is relatively large (14 mL/kg/min), and its elimination half-life is relatively short (103 to 134 minutes).^{[22] [23]} Its time course of disappearance from plasma is similar to that of fentanyl, yet the discrepancy in duration of effect of the two has been the subject of criticism because both are formulated together in Innovar. The seemingly longer CNS action of droperidol has prompted some investigators to postulate that droperidol has a propensity to occupy CNS receptors^[22] and that it undergoes greater receptor binding than fentanyl does.