Pharmacokinetics and pharmacodynamics of vecuronium (ORG NC 45) in patients with cirrhosis.

To evaluate the effect of liver cirrhosis on the pharmacokinetics and the pharmacodynamics of vecuronium, 12 patients with cirrhosis, aged (mean +/- SD) 52 +/- 12 yr, and 14 control patients, 42 +/- 15 yr, undergoing elective surgery under general anesthesia were studied. The simultaneous time courses of the plasma concentration of vecuronium and of the neuromuscular blockade were studied after the administration of a bolus dose of 0.2 mg X kg-1. Vecuronium plasma concentration declined biexponentially in both groups. Vecuronium plasma clearance was reduced significantly (P less than 0.01) from 4.26 +/- 1.38 ml X min-1 X kg-1 in the controls to 2.73 +/- 1.19 ml X min-1 X kg-1 in the patients with cirrhosis. The elimination half-life was 58 +/- 19 min in the controls and was prolonged significantly to 84 +/- 23 min (P less than 0.01) in the patients with cirrhosis. The total apparent volume of distribution was unchanged in patients with cirrhosis (0.253 +/- 0.086 1 X kg-1 vs. 0.246 +/- 0.092 1 X kg-1 in the controls). Cirrhosis caused a prolongation of the neuromuscular blockade induced by vecuronium: the duration of effect from injection to 50% recovery of the twitch height was prolonged by 100% (P less than 0.01) from 62 +/- 16 min in the controls to 130 +/- 52 min in patients with cirrhosis. The recovery rate (TH 25-75) also was prolonged (P less than 0.05) from 21 +/- 7 min in the controls to 44 +/- 18 min in patients with cirrhosis.(ABSTRACT TRUNCATED AT 250 WORDS)