Pharmacokinetics of Org NC45 (norcuron) in patients with and without renal failure

To determine the influence of renal failure on the pharmacokinetics and neuromuscular blockade of Org NC 45 (Norcuron), a new monoquaternary homologue of pancuronium, 13 patients under halothane and nitrous oxide anesthesia were studied. Org NC 45 was administered by 2-min infusion in doses of 0.28 mg kg-1 (normal renal function group, n = 4) and 0.14 mg kg-1 (renal failure group, n = 5). Four additional patients with normal renal function were given Org NC 45 0.14 mg kg-1 to determine the onset, duration and recovery rate of neuromuscular blockade. The serum concentration of Org NC 45 was determined by normal-phase high performance liquid chromatography (sensitivity 50 ng ml-1), and a two-compartment open pharmacokinetic model was fitted to resulting data. Estimates of distribution half-life (T 1/2 alpha), elimination half-life (T 1/2 beta), volume of distribution at steady state (Vss) and clearance of Org NC 45 did not differ significantly between patients with normal renal function and those with renal failure. The onset, duration and recovery rate times of the neuromuscular blockade by Org NC 45 0.14 mg kg-1 in patients with normal renal function and those with renal failure did not differ significantly.