NYSDOH-OASAS Health Advisory: Levamisole-Contaminated Cocaine

This Health Advisory highlights levamisole-contaminated cocaine as a growing problem in the United States (US) and other countries. Patients exposed to levamisole-contaminated cocaine have been identified in several US states, 1 including New York State (NYS). 2 In July 2009, the US Drug Enforcement Agency (DEA) reported that 69% of cocaine entering the US contained levamisole. 1 The DEA has also detected trace amounts of levamisole in heroin seizures. 1

Levamisole is a veterinary antihelmintic medication. Levamisole-contaminated cocaine is associated with severe side effects including agranulocytosis leading to increased susceptibility to infection. It is also associated with vasculitis and necrotic skin lesions in unusual locations, such as ear lobes and face.

Clinical Presentation

Clinicians should consider the possibility of exposure to cocaine contaminated with levamisole in patients with symptoms listed below and obtain a drug history from potential cases in a nonjudgmental manner. Symptoms may mirror those of leukemia or an autoimmune disorder and include:

  • Unexplained fever and agranulocytosis
  • Unexplained vasculitis with pupuric skin lesions over ear lobes, legs and thighs
  • Persistent or recurrent fever and chills
  • Worsening or persistent sore throat
  • Worsening swollen glands
  • Painful sores in the mouth or around the anus
  • Frequent, persistent or worsening skin infections
  • Thrush
  • Other unusual infection(s)

Testing and Treatment

Because levamisole has a short half-life (5.6 hours), testing of blood or urine for levamisole should be done within 48 hours of last use. Routine immunoassays toxicology screens do not detect levamisole. Other methods, such as gas chromatography/mass spectrometry, are required. Agranulocytosis is self-resolving with withdrawal of the drug, severe cases have been treated with filgastrim.

The NYS Office of Alcoholism and Substance Abuse Services (OASAS) provides an on-line directory of chemical dependence programs.

The New York City Department of Health and Mental Hygiene (NYCDOHMH) requires all medical providers in NYC to report cases of cocaine-using patients who present with unexplained neutropenia or vasculitis to the NYC Poison Control Center at 1-800-222-1222 or 212-764-7667 (212-POISONS). See the NYCDOHMH 2010 Health Advisory #14: Possible Levamisole-induced Toxicity in Cocaine-Using Patients.

Brief Background on Levamisole-Contaminated Cocaine

Pharmaceutical agents, including levamisole, have been found in cocaine supplies in Europe and North America since at least 2004. 3-5 Levamisole is an antiparasitic drug used by veterinarians. It is currently approved for use in cattle, sheep and swine. Although levamisole was previously used to treat autoimmune diseases and cancer in humans, it is no longer an approved drug for human use. 6


  1. USDHHS. Centers for Disease Control and Prevention. Agranulocytosis Associated with Cocaine Use - Four States, March 2008 - November 2009. MMWR. 2009. 58(49); 1381-1385.
  2. Bradford M, Rosenberg B, Moreno J, Dumyati G. Bilateral necrosis of Earlobes and Cheeks: Another Complication of Cocaine Contaminated with Levamisole. Ann Int Med. 2010. 152(11): 758-759.
  3. Fucci N. Unusual adulterants in cocaine seized on Italian clandestine market. [Letter]. Forensic Sci Int. 2007. 172 (2-3); el.
  4. Raymon LP, Isenschmid DS. [Letter]. The Possible Role of Levamisole in Illicit Cocaine Preparations. J Anal Tox. 2009. 33; 620-621.
  5. Zhu NY, LeGatt DF, Turner AR. Agranulocytosis After Consumption of Cocaine Contaminated with Levamisole. Ann Int Med. 2009. 150(4); 287-289.
  6. USDHHS. Substance Abuse & Mental Health Services Administration. Nationwide Public Health Alert Issued Concerning Life-Threatening Risk Posed by Cocaine Laced with Veterinary Anti-Parasite Drug. 9/21/09.

Additional Resources