Which of the following drug causes flaccid paralysis of ascaris?
High-Yield Explanation
Pyrantel causes activation of nicotinic cholinergic receptors in the worms resulting in persistent depolarization-- slowly developing contracture and spastic paralysis. Worms are then expelled. An anticholinesterase action has also been demonstrated. Because piperazine causes hyperpolarization and flaccid paralysis, it antagonizes the action of pyrantel. Cholinergic receptors in mammalian skeletal muscle have very low affinity for pyrantel. Only 10-15% of an oral dose ESSENTIALS OF PHARMACOLOGY page no. 852