• Levamisole belongs to the imidazothiazoles class of drugs.
  • This is one of the most widely used anthelmintics and can be given orally, by injection or as a pour on.
  • It is active against adult Nematodes, but has limited action against the larval stages, especially the hypobiotic phase.
  • It is a cholinergic agonist at neural and neuromuscular junctions causing a spastic paralysis of the nematode. The nematodes succumb rapidly to it.
  • It is rapidly absorbed and excreted and its potency is related to its peak plasma concentrations. Therefore pour-on products need a higher dose, as they are absorbed more slowly, to reach the same plasma concentrations.