Table 1. Alfentanil and Fentanyl Pharmacokinetic Parameters

*P < 0.05 vs.  placebo.

AUC^0-∞= area under the plasma time–concentration time curve extrapolated to infinity; AUC^0-loq= area under the plasma time–concentration time curve to the last quantifiable concentration; CL = plasma clearance; Cmax = time to maximum plasma concentration; Kel = terminal elimination rate constant; T1/2 = terminal elimination half-life; Tmax = time to maximum plasma concentration; VDss = distribution volume.