ABSTRACT
To determine the neuromuscular effect and its reversals of gentamicin, alone or in combination with metocurine, pharmacodynamic studies were done using a common peroneal nerve- anterior tibialis muscle preparation in 24 adult cats weighing 2.5-4.0 kg. The median effective dose of gentamicin obtained by cumulative dose-response study was 21.6+/-4.83 mg/kg. Under the pretreatment of gentamicin, the onset and duration of metocurine was 1.32+/-0.91 min and 28.8+/-10.95 min, respectively. There was no significant difference in the recovery indicies for its reversal between neostigmine and calcium. Each values of recovery indices were 1.85+/-0.65 and 2.05+/-1.00 min with neostigmine and calcium, respectively. These results suggested that gentamicin by itself had neuromuscular blocking effect. With the pretreatrnent of gentamicin, the onset of metocurine was shortened to one third and its duration was prolonged as much as seven times. Additionally, metocurine induced neuromuscular block with pretreatment of gentamicin was reversed completely.