Pharmacokinetics of 51W89: preliminary data.

The pharmacokinetics of the 1R cis-1'R cis-isomer of atracurium (51W89) and its metabolite, laudanosine, were studied in 11 healthy patients with normal renal function and in 12 patients with chronic renal failure undergoing regular dialysis. A bolus dose of 51W89 (0.1 mg/kg) was given, and the plasma concentration was measured at regular intervals for 480 min. The elimination half-life of 51W89 was significantly longer in renal failure patients than in healthy controls (38.9 min vs 30.6 min; P < 0.05). The plasma laudanosine levels were lower than those reported after an equipotent dose of atracurium besylate. 51W89 may have a prolonged effect in renal failure patients.