Pyrantel was first introduced as a broad-spectrum anthelmintic against GI nematodes of sheep and has also been used in cattle, horses, dogs, cats, and pigs. It is available as a citrate, tartrate, embonate, or pamoate salt.
Aqueous solutions are subject to isomerization on exposure to light, with a resultant loss in potency; therefore, suspensions should be kept out of direct sunlight. It is not recommended for use in severely debilitated animals because of its levamisole-type pharmacologic action.
Pyrantel is used PO as a suspension, paste, drench, or tablets. Both pyrantel and morantel are effective against adult gut worms and larval stages that dwell in the lumen or on the mucosal surface.