INTERACTION OF MIDAZOLAM WITH TWO NON-DEPOLARIZING NEUROMUSCULAR BLOCKING DRUGS IN THE RAT IN VIVO SCIATIC NERVE-TIBIALIS ANTERIOR MUSCLE PREPARATION

Studies of the possible interactions between the water-solublebenzodiazepine, midazolam, and two non-depolarizing neuromuscularblocking drugs, vecuronium and tubocurarine, were performedin the rat in vivo sciatic nerve-tibialis anterior muscle preparation.Midazolam 0.5 and 5 mg kg^–1 caused 17% and 34% depressionof the twitch height, respectively, once a steady-state blockadeof the twitch height had been induced by vecuronium. The potentiationof the tubocurarine steady state blockade by midazolam 5 mgkg^–1 was quantitatively equal to that of vecuronium, butwas slower in onset. The buffer solvent of midazolam 5 mg kg^–1did not change the steady-state blockade of vecuronium. Midazolam5 mg kg^–1 caused a shift to the left of the cumulativedose-response curves of vecuronium.