A Confirmed Case of Agranulocytosis after Use of Cocaine Contaminated with Levamisole

More than 2 million Americans use cocaine each month (National Survey on Drug Use and Health, Department of Health and Human Services: Substance Abuse and Mental Health Services Administration (SAMHSA) & Office of Applied Studies (OAS), Rockville, MD 2007). Starting in early 2003, South American cocaine cartels began to add levamisole, a pharmaceutical agent, to bulk cocaine prior to shipment to the USA (Valentino and Fuentecilla 2005). A dramatic increase in the prevalence of levamisole in cocaine was noted in early 2008. By October, 30% of cocaine bricks analyzed by the United States Drug Enforcement Administration contained levamisole (Casale et al. 2008). Exposure to levamisole can cause agranulocytosis (Amery and Bruynseels 1992). We report the first confirmed case of agranulocytosis associated with consumption of levamisole-contaminated cocaine in the USA. A previously healthy adult male presented to the emergency department with 5 days of mouth pain. He admitted to chronic active ethanol and crack cocaine abuse. Laboratory studies revealed severe neutropenia, with an absolute neutrophil count of 19 cells/mm3 (normal = 1,500-8,000 cells/mm3). A urine screen for drugs of abuse was positive for cocaine metabolites and opiates. Evaluation of a peripheral blood smear showed leukopenia with severe absolute neutropenia. A bone marrow biopsy revealed recently injured bone marrow showing early recovery. While in the hospital, the patient had little spontaneous bone marrow recovery. He received granulocyte colony-stimulating factor with improvement in peripheral white blood cell counts. The residue in the patient's crack pipe contained 10% levamisole. Subsequently, levamisole was detected in the patient's urine. Levamisole-associated agranulocytosis should be considered in the diagnosis of patients who present with neutropenia and a history or evidence of cocaine use. © 2010 American College of Medical Toxicology.