PHARMACODYNAMICS AND PHARMACOKINETICS OF ROCURONIUM BROMIDE IN PATIENTS WITH AND WITHOUT RENAL-FAILURE (REPRINTED FROM BR-J-ANAESTH, VOL 71, PG 222, 1993)

We have studied the onset and duration of action and pharmacokinetics of rocuronium bromide during anaesthesia with nitrous oxide, fentanyl and isoflurane after a single bolus dose of rocuronium 0.6 mg kg-1 in nine patients with chronic renal failure requiring regular haemodialys is, and in nine healthy control patients. Blood samples were collected over 390 min and concentrations of rocuronium and its putative metabo lites measured using HPLC. Onset time for maximum block, duration of c linical relaxation DUR25 and recovery index, were 61 (SD 25.0) s and 6 5 (16.4) s, 55 (26.9) min and 42 (9.3) min and 28 (1 2.3) min and 1 9 (8.8) min, respectively, for patients with and without renal failure. The time for train-of-four ratio to return spontaneously to 0.7 was 99 (41.1 ) min and 73 (24.2) min, respectively, in the two groups. None of these differences was significant. The pharmacokinetic data were be st described by a three-exponential equation. There were significant d ifferences between patients with and without renal failure in the rate s of clearance (2.5 (1.1 ) ml kg-1 min-1 and 3.7 (1.4) ml kg-1 min-1, respectively) and the mean residence times (97.1 (48.7) min and 58.3 ( 9.6) min) (P<0.05). The differences in other kinetic parameters were n ot significant. We conclude that the effects of rocuronium may be prol onged in patients with renal disease because of a decreased clearance of the drug.