Effect of beta-diethylaminoethyl 3,3-diphenylpropylacetate on the action of suxamethonium and other neuromuscular blocking drugs.

On the frog rectus abdominis muscle and on sciatic nerve-tibialis anterior muscle preparations, beta-diethylaminoethyl 3,3-diphenylpropylacetate (SKF 525A) antagonized the actions of acetylcholine and potassium chloride as well as having an antiveratrine action. The blocking action at the skeletal neuromuscular junction of suxamethonium and its disulphonium analogue, decamethonium, tubocurarine and gallamine was enhanced by SKF 525A in the rabbit and in the isolated rat phrenic nerve-diaphragm preparation. The activity of suxamethonium and decamethonium in the cat was reduced. On the rat phrenic nerve-diaphragm preparation, pretreatment with SKF 525A abolished both the mutual antagonism between suxamethonium and tubocurarine and the antagonizing effect of tetraethylammonium against suxamethonium. Theantagonism between tetraethylammonium and tubocurarine was unimpaired.