Vancomycin-induced neutropenia during treatment of osteomyelitis in an outpatient.

A case of vancomycin-associated neutropenia occurring during long-term outpatient therapy with vancomycin is described. Pharmacokinetic studies demonstrated that the patient's vancomycin serum levels were within an acceptable range during treatment. Eighteen other reported cases of vancomycin-associated leukopenia are discussed in brief. An immunologic mechanism has been proposed but a clear understanding is lacking. Patients receiving long-term vancomycin therapy should have their white blood cell counts periodically monitored.