DISPOSITION KINETICS OF PANCURONIUM BROMIDE IN PATIENTS WITH TOTAL BILIARY OBSTRUCTION

Plasma concentrations of pancuronium were measured in nine patientsundergoing surgery because of total biliary obstruction. Whencompared with the averaged model-independent pharmacokineticparameters obtained for normal patients, the terminal half-lifeof 270 min was more than twice normal (132 min, P<0.001);the plasma clearance of 59 ml min^–1 was less than halfthe normal rate for pancuronium (123 ml min^–1, P<0.003).These significant alterations to the pharmaco–kineticsof pancuronium were associated with prolongation of neuromuscularblockade. Following a bolus injection of pancuronium 6 mg, therewas a mean time of 114 min (normals 70 min, P <0.05) beforethe evoked twitch response had returned to 5% of the controlvalue. The pattern of urinary excretion of the drug and itsmetabolites did not differ from that of normal patients. Toavoid excessive dosage during prolonged surgery for total biliaryobstruction, it is recommended that supramaximal nerve stimulationbe used to indicate the need for the administration of furtherdoses of pancuronium.