Moxifloxacin-Induced Immune-Mediated Thrombocytopenia in a Chronic Kidney Disease Patient Receiving Hemodialysis

Objective:To alert clinicians to a serious complication from a commonly prescribed medication, moxifloxacin. Case Summary: A 65-year-old male, septic, hemodialysis patient developed thrombocytopenia following exposure to vancomycin, ceftazidime, and moxifloxacin. Drug-specific immunoglobulin testing showed positive autoantibodies against only moxifloxacin, and the probability stratification proposed by Naranjo et al would give this case a score of 7 a probable association between moxifloxacin and the adverse event. Discussion: Idiopathic thrombocytopenic purpura (ITP) results in immune-mediated platelet destruction, with bleeding risk frequently manifested by purpuric skin and mucosa! lesions. Although many drugs are associated with ITP, moxifloxacin has only been characterized in 2 previous case reports. This is the first case report where specific immunoglobulin antibody testing showed a positive association between ITP and moxifloxacin. Conclusions: Moxifloxacin is a commonly prescribed medication because of its wide spectrum of activity, high bioavailability, and convenient dose schedule. Clinicians need to be aware of this little-known side effect of this commonly prescribed antibiotic.