RESUMO
BACKGROUND: Duration of action varies in conditions with reduced plasma cholinesterase activity. To evaluate the action duration and recovery of mivacurium under the experimental hepatic failure and cholestasis, the pharmacodynamic studies were done. METHODS: The pharmacodynamic studies were done using a common peroneal nerve-anterior tibialis muscle preparation in 18, either sex, adult cats (weight, 2.0~4.0 kg). For the hepatic failure, galactosamine chloride (4.25 mmol/kg) was given 16 hours prior to the pharmacodynamic study. The cholestasis was made by the ligation of CBD and cystic duct 8 days prior to the pharmacodynamic study. All the cat had 4XED95 of mivacurium. The action durations and recovery indices were measured. And plasma cholinesterase activities were checked. RESULTS: The duration of mivacurium was prolonged significantly with either hepatic failure (14.96 4.44 min.) or cholestasis (11.21+/- 5.11 min.) group compared to control group (5.27 +/-0.67 min.) and also the recovery indices were significantly increased in the hepatic failure (4.58+/- 1.40 min.) and cholestasis (3.21+/- 1.00 min.) groups, as compaired with the control group (1.57+/- 0.40 min.). CONCLUSION: The mivacurium-induced neuromuscular blockade is prolonged by the experimental hepatic failure and cholestasis, and the effects may be caused by the hepatic dysfunction, impairment of direct biliary excretion.