Interaction of Verapamil with Gallamine and Pancuronium and Reversal of Combined Neuromuscular Blockade with Neostigmine and Edrophonium

In this in vitro study, the effects and interactions of verapamil with gallamine and pancuronium and reversal by edrophonium and neostigmine of combined neuromuscular blockade, produced by the muscle relaxants and verapamil, were studied in an avian skeletal muscle. The results show that verapamil reduced the amplitude of indirectly-elicited twitch tension and potentiated the neuromuscular blockade produce by the two muscle relaxants. Edrophonium and neostigmine reversed the neuromuscular blockade produce by the muscle relaxants alone, and in combination with verapamil. Edrophonium was more potent than neostigmine in reversing the combined neuromuscular blockade produced by the muscle relaxants with and without verapamil.