Severe thrombocytopenia associated with alatrofloxacin

To report the development of severe thrombocytopenia during alatrofloxacin therapy.

A 54-year-old Native American woman was admitted for pneumonia after completing a 10-day course of loracarbef 200 mg po bid. On admission, the woman was hypoxic (PO2 56 mm Hg) and had a platelet count of 408 x 10(3)/mm3. Alatrofloxacin 300 mg iv piggyback qd was initiated in the emergency department. The patient's condition gradually improved during the next three days. While preparing for discharge on hospital day 4, the patient developed epistaxis that lasted approximately three hours. Laboratory testing revealed a platelet count of 7 x 10(3)/mm3; stable red blood cell count, hemoglobin, and hematocrit values; and a normal white blood cell count. Alatrofloxacin therapy was discontinued and azithromycin was initiated on hospital day 4. Methylprednisolone 125 mg iv piggyback every 12 hours was initiated on hospital day 5. The platelet count fell to 2 x 10(3)/mm3 on hospital day 5 and then began to rise, reaching 60 x 10(3)/mm3 when the patient was discharged on hospital day 8.

Numerous infectious, disease-related, environmental, and pharmacologic factors may cause thrombocytopenia. Drug-induced thrombocytopenia usually develops during the first two weeks of therapy and resolves within one week of drug discontinuation. Thrombocytopenia occurred in <1% of more than 7000 patients receiving alatrofloxacin or trovafloxacin during clinical trials.

The time course of this patient's development of and recovery from thrombocytopenia suggests that it was induced by alatrofloxacin. Clinicians should monitor patients receiving alatrofloxacin or trovafloxacin for signs and symptoms of bleeding and thrombocytopenia.