Agranulocytosis from Levamisole-Adulterated Cocaine

Introduction: Afebrile neutropenia with an absolute neutrophil count (ANC) of zero in a nonimmunocompromised individual is unusual. Outlined is a case of agranulocytosis likely due to levamisole laced cocaine. Given recent publications in the news media and medical journals, this is a pertinent issue for primary care providers. Case: A 57-year-old female presented with painful bowel movements and difficulty eating. Physical examination revealed two exquisitely tender ulcerated lesions on her lower lip and anus. Laboratory data revealed an ANC of 0 and urine drug screen positive for cocaine. She was prophylaxed with acyclovir, diflucan, and ciprofloxacin, and was started on granulocyte colony stimulating factor for four days. Her ANC normalized, but the cause of her severe neutropenia remained unclear. Discussion: Levamisole is a veterinary antihelminthic used for treatment of rheumatoid arthritis and colorectal cancer in humans. 88% of regional cocaine samples are testing positive for levamisole, which is thought to potentiate cocaine's effects but can also cause agranulocytosis. Conclusions: Our patient did not fit the clinical picture for malignancy, viral infection, or bone marrow pathology. Given the high rate of levamisole adulterated cocaine and an otherwise negative work-up, this is the most likely explanation for her agranulocytosis. (J Am Board Fam Med 2012;25:528-530.)