Potentially Fatal Neutropenia Associated with the Use of Cocaine Adulterated with Levamisole.

Cases of neutropenia associated with the use of cocaine adulterated with levamisole are being increasingly reported and have become a serious public health hazard. As reported by the US Drug Enforcement Administration (DEA) up to 69% of total cocaine seized in the US is adulterated with this veterinary antihelminthic known to cause agranulocytosis in certain susceptible populations. The rationale for selecting levamisole as an adulterant is unclear, but is likely related to the fact that it shares some physico-chemical properties with cocaine and potentiates the activity of dopaminergic (D2) and NMDA receptors in brain thus enhancing its effects.

A case review was performed of adult patients who presented with neutropenia after the use of levamisole adulterated cocaine. Their laboratory results and treatment outcomes were studied to establish an expected course of the illness.

Over a one year period, 5 patients (4 female, 1 male) with age range of 45–60 years, presented with neutropenia in the setting of cocaine use. 4 were positive for levimasole in urine (detected by the use of gas chromatography/mass spectrometry analysis within 4–6 hours of presentation). Bone marrow biopsies were performed in 4 cases showed granulocytic hypoplasia with myeloid maturation arrest, lymphocytic hyperplasia and polytypic plasma cells. Antigranulocyte antibodies (AGA) were positive in 3 of the 4 patients tested. One each had positive serology for serum fluorescent antinuclear antibody (FANA), rheumatoid factor (RF) and antineutrophil cytoplasmic antibody (ANCA). Four of the five patients had hepatitis C infection. One patient had marginal zone B cell lymphoma and another was diagnosed with HIV at her first presentation. The median duration of neutropenia was 5–7 days. 2 patients died as a result of their various co-morbidities. Discussion: Use of cocaine adulterated with levamisole can result in profound neutropenia which could be fatal despite aggressive medical therapy. In patients presenting with neutropenia and a history of substance abuse, a high index of suspicion for cocaine adulterated with levamisole is needed and can be confirmed with rapid testing for both substances in patients' urine. Further diagnostic studies including a bone marrow biopsy with characteristic findings as described above and serologic testing for AGA can aid in confirming the diagnosis and ruling out other common causes of neutropenia. The treatment is usually supportive and based on the Infectious Diseases Society of America (IDSA) guidelines for managing neutropenic patients. The role of public health advisories in providing awareness among patients and care givers cannot be overstated, which can lead to early detection and reduced mortality.

No relevant conflicts of interest to declare.