Pyrantel
Pyrantel is a pyrimidine-derivative anthelmintic agent for the oral treatment of various parasitic worm infections including ascariasis, hookworm infections, enterobiasis (pinworm infection), trichostrongyliasis, and trichinellosis.  Pyrantel was initially described in 1965 by researchers from Pfizer who sought cyclic amidines with suitable pharmacokinetic properties (specifically, duration of action) for use as an anthelmintic drug. Pyrantel is mainly available in formulations for dogs and cats as the embonate salt, containing a 34.7% pyrantel base.    Pyrantel is on the World Health Organization's List of Essential Medicines, which are the safest and most effective medicines required in a functioning health system,.    A depolarizing neuromuscular-blocking agent causing longstanding nicotinic receptor activation, resulting in spastic paralysis of susceptible nematodes (worms). Pyrantel has shown to be effective after a single dose.  In humans, it is administered as pyrantel pamoate,,,.