August 6, 2020
Levamisole – A Toxic Adulterant Found in Illicit Street Drugs
Levamisole was initially developed in the mid-1960s as a veterinary and human anti-worming drug. In 1990, it was approved by the United States Food and Drug Administration (FDA) as a therapy for the treatment of colorectal cancer, however, by 2000 it had been withdrawn from the market due to severe adverse effects described below. Since the early 2000’s, levamisole has been in widespread use as an adulterating agent for illicit street drugs, especially cocaine, heroin, and fentanyl. Although its prevalence varies over time and geographically, LEVAMISOLE HAS AT TIMES BEEN DETECTED IN UP TO 79% OF THE COCAINE STREET SUPPLY AT VARYING PERCENTAGES, UP TO 74% BY WEIGHT.