[Randomized, multicenter study of interaction between Org 9426 (rocuronium bromide) and anesthetic agents in Japanese population].

BACKGROUND

The purpose of this randomized, multi-center phase III trial was to investigate the influence of sevoflurane and propofol on the neuromuscular blocking effects and pharmacokinetic parameters of Org 9426 (rocuronium bromide) in Japanese population.

METHODS

Thirty-nine adult Japanese patients participated in this randomized, multi-center study. Neuromuscular function was monitored continuously with TOF-Watch SX (Organon NV, Netherlands) after anesthetic induction with propofol. These subjects randomly received either 0.6 mg x kg(-1) or 0.9 mg x kg(-1) of rocuronium for endotracheal intubation. These two groups were further divided to two anesthetic regiments : sevoflurane group and propofol group. The difference in onset and recovery of rocuronium-induced neuromuscular block was statistically analyzed with two-way ANOVA.

RESULTS

Mean duration for maximal block was 76 seconds and 66 seconds, respectively. The duration between Org 9426 administration and 25% recovery of first twitch response was significantly prolonged in patients given 0.9 mg x kg(-1) of Org 9426. Sevoflurane also significantly increased this duration. However, the serum concentration of Org 9426 was not statistically different between the four study groups.

CONCLUSIONS

The duration of Org 9426-induced neuromuscular blockade was significantly increased under sevoflurane anesthesia compared to propofol anesthesia. This difference may be attributed to pharmacodynamic change.