Effective reversal of moderate rocuronium- or vecuronium-induced neuromuscular block with sugammadex, a selective relaxant binding agent.

Background: Sugammadex rapidly reverses rocuronium-induced neuromuscular block. This study explored the dose-response relation of sugammadex given as a reversal agent at reappearance of the second muscle twitch after rocuronium- and vecuronium-induced block. A secondary objective was to investigate the safety of single doses of sugammadex.

Methods: In this two-center, phase II, dose-finding study, 80 patients (age >or= 18 yr, American Society of Anesthesiologists physical status I or II, surgery >or= 60 min requiring muscle relaxation for intubation) were randomly assigned to receive rocuronium (0.60 mg/kg) or vecuronium (0.10 mg/kg). Sugammadex or placebo was administered at reappearance of the second muscle twitch. The primary efficacy endpoint was time from starting sugammadex administration until recovery of the train-of-four ratio to 0.9.

Results: Compared with placebo, sugammadex produced dose-dependent decreases in mean time to recovery for all train-of-four ratios in the rocuronium and vecuronium groups. The mean time for recovery of the train-of-four ratio to 0.9 in the rocuronium group was 31.8 min after placebo compared with 3.7 and 1.1 min after 0.5 and 4.0 mg/kg sugammadex, respectively. The mean time for recovery of the train-of-four ratio to 0.9 in the vecuronium group was 48.8 min after placebo, compared with 2.5 and 1.4 min after 1.0 and 8.0 mg/kg sugammadex, respectively. Sugammadex was well tolerated.

Conclusion: Sugammadex rapidly reversed rocuronium- or vecuronium-induced neuromuscular block at reappearance of the second muscle twitch and was well tolerated. A dose-response relation was observed with sugammadex for reversal of both rocuronium- and vecuronium-induced neuromuscular block.