Leukocytopenia, thrombocytopenia and fever related to piperacillin/tazobactam treatment--a retrospective analysis in 38 children with cystic fibrosis.

Bone marrow suppression is an important adverse reaction to most betalactam antibiotics. Recently it was suggested that piperacillin/tazobactam (PT) also may cause bone marrow toxicity. We retrospectively analyzed 100 i.v. antibiotic treatment courses (mean duration 12.5 days) in 38 patients (median age 14 years) with cystic fibrosis (CF) who were treated in our hospital. Of the patients receiving PT (84%), 6 patients (18.75% of PT-treated patients, 10.3% of PT treatment courses) developed fever, malaise and headache during treatment without signs of acute infection. In one patient definite thrombocytopenia and neutropenia, in two others a milder decrease in leukocyte and thrombocyte counts was observed after the onset of fever. The events were time- and dose-dependent occurring between day 11 and 15 of treatment. Treatment courses lasted longer (14.2 vs 11.3 days; p < 0.05) and patients had received a higher cumulative dose of PT (4919 +/- 1975 mg/kg b.w. vs 3161 +/- 1635 mg/kg; p < 0.02, Student's t-test) in the affected group than in the unaffected group. After discontinuation of PT, fever subsided within 24 h and blood cell counts normalized. We hypothesize that these fever episodes and changes of blood parameters are related to PT therapy.