Pharmacokinetics of atracurium and its metabolites in patients with normal renal function, and in patients in renal failure.

The plasma pharmacokinetic profiles of atracurium and its derivatives, laudanosine and monoquaternary alcohol, were studied in six patients with renal failure after a bolus dose of atracurium 0.3-0.4 mg kg-1. The pharmacokinetics of the derivatives only were studied in a group of four normal patients receiving atracurium 0.3 mg kg-1. Measurements of plasma and urine concentrations were performed by high pressure liquid chromatography. Pharmacokinetics of atracurium were not significantly different in the renal failure group when compared with those obtained in a previous study on six normal patients. Although 2-10% of the dose was recovered in the urine of normal patients as unchanged atracurium, and 3-4% as laudanosine, renal failure produced no significant differences in plasma pharmacokinetics, with mean plasma elimination half-lives of 20 min for atracurium, 234 min for laudanosine and 39 min for quaternary alcohol.