Pharmacokinetics and pharmacodynamics of rocuronium bromide in adult patients

In seven patients (M/F: 4:3) rocuronium 0.6 mg kg-1 was given after the induction of anaesthesia with propofol, and during maintenance with N2O/O2, halothane 0.5% and alfentanil 60-90 micrograms kg-1 h-1. Intubation conditions were scored at 60 s and lag time, onset time, maximal block achieved, recovery to 25% of T1, and Recovery Index, were measured using a Relaxograph. Blood samples were taken over a 300 min period and analysed for rocuronium. Intubating conditions at 60 s were excellent in all patients. Mean clearance was 5.2 ml kg-1 min-1, the terminal half-life was 69 min and distribution volume at steady state was 0.22 litre kg-1. Cumulative urinary excretion was around 18% within 24 h.