Levamisole Induced Necrosis Syndrome or Levamisole-induced vasculitis, is a circulatory disease caused by exposure to the veterinary medication levamisole, usually when the chemical is used to "cut" cocaine. Levamisole is an acetycholine receptor antagonist and is an effective treatment of heartworms. However, its use was discontinued in humans due to serious side effects, most often the destruction of white blood cells. In severe cases, this can restrict or occlude blood vessels leading to necrosis. ,