A comparison between vecuronium and atracurium in myasthenia gravis

We evaluated the effect of vecuronium bromide and atracurium besylate on the train–of–four response in the management of muscle relaxation in 20 patients with myasthenia gravis (MG) who were undergoing thymectomy. We confirmed the safe use of these two non–depolarizing muscle relaxants in MG patients. Vecuronium (0.04 mg–kg^‐1) demonstrated a lesser clinical duration than did atracurium (0.2 mg–kg^‐1) (38± 19 vs 50 ± 21 min, mean ± s.e.mean). The recovery time for vecuronium patients was shorter than that for atracurium patients (22 ± 18 vs 38± 18 min), but the time until onset of neuromuscular blockade was longer with vecuronium (246 ±105 vs 107 ± 103 s). During spontaneous recovery from neuromuscular relaxation, at Tl/C of 25% and 100%, the train–of–four fade with vecuronium was significantly greater than that with atracurium (0.04 ± 0.02, 0.16 ± 0.03 vs 0.17 ±0.01, 0.83 ± 0.03), suggesting that vecuronium had a greater prejunctional effect than did atracurium.