The pharmacokinetics of sufentanil, a new thienyl analogue of fentanyl, were studied in 10 surgical patients. Sufentanil, 5 [mu]g/kg, was given intravenously as a bolus injection and plasma concentrations measured at intervals up to 8 h. Plasma sufentanil concentrations decreased rapidly after injection-98% of the administered dose having left the plasma within 30 min. In 9 of the 10 patients, a tri-exponential equation optimally described the sufentanil concentration decay curve, with average (+/-SEM) half-lives for the rapid ([pi]) and slow ([alpha]) distribution phases of 1.4 +/- 0.3 min and 17.7 +/- 2.6 min, respectively. The average terminal elimination ([beta]) half-life was 164 +/- 22 min. The average value for Vd[beta] was 2.9 +/- 0.2 1/kg, Vdss 1.7 +/- 0.2 1/kg and total plasma clearance 12.7 +/- 0.8 ml [middle dot] kg-1 [middle dot] min-1 (935 +/- 50 ml/min). In one patient, a biexponential equation was sufficient to describe the concentration-time data, yielding a distribution half-life of 4.7 min and an elimination half-life of 117 min.
(C) 1984 American Society of Anesthesiologists, Inc.