Using the Non Depolarizing Neuromuscular Blocking Agent Vecuronium in Patients with Liver Dysfunction: Muscle Relaxants and Liver Dysfunction

The main rout of excretion of the aminosteroid non-depolarizing neuromuscular blocking drug vecuronium bromide is through hepatic metabolism. Using the Relaxometer mechanomyograph we assessed the effect of various grades of liver dysfunction on vecuronium bromide pharmacodynamics in 21 patients with mild liver dysfunction and 4 patients with severe liver dysfunction compared with 20 subjects with normal liver function. There was no significant difference in the intubation score or onset time (time from the beginning of vecuronium administration till maximal neuromuscular block) between patients with or without liver dysfunction. The Clinical Duration (time from the beginning of vecuronium administration till 25% first twitch T1 recovery), Recovery Index (time from 25% to 75% T1 recovery), as well as the End Stage Time (time from the beginning of vecuronium administration till 0.7 Train-of-four TOF ratio recovery) were all statistically significantly prolonged in the Mild and Severe Liver dysfunction groups compared with the control group. We concluded that liver dysfunction exponentially prolongs the pharmacodynamic effects of the non-depolarizing neuromuscular blocking drug vecuronium bromide that is mainly excreted through hepatic metabolism.