Efficacy and tolerability of prophylactic treatment with intravenous piperacillin/tazobactam in patients undergoing hematopoietic stem cell transplantation.

Background: Infections remain a major cause of morbidity and mortality in patients undergoing autologous or allogeneic hematopoietic stem cell transplantation (HSCT). About 80% of patients experience fever during aplasia and early engraftment despite oral antibacterial chemoprophylaxis.
Methods: In a pilot study, 50 patients undergoing autologous or allogeneic HSCT received a prophylactic antibacterial treatment with intravenous piperacillin/tazobactam beginning on day of stem cell or bone marrow transfusion. They were analyzed retrospectively for frequencies of fever of unknown origin (FUO), documented infection, bacteremia and death because of infection. Furthermore, data from microbiological monitoring and tolerability were evaluated.
Results: Among 28 autologous transplanted patients, 10 (36%) developed fever more than 38.5 degrees C; 9/10 FUO, 1/28 pulmonary infiltrates. Eighteen patients (64%) remained without any symptom of infection. In the allogeneic group (n = 22), there were eight patients (36%) with FUO, and five patients (23%) with documented infections (pneumonia 2, enteritis 1, pyelonephritis 1, Escherichia coli bacteremia 1). In nine patients (41%), escalation of antimicrobial treatment was not necessary. The majority of detected microbes in cultures of throat and nose secretions, blood, urine and stool were gram-positive bacteria (77.8%), among them Staphylococcus epidermidis (23.5%), streptococci (group A, B, C; 21.0%) and enterococci (10.6%). Incidence of gram-negative bacteria and fungi was similar with 11.8% and 10.4%, respectively. The most frequent gram-negative strains were Escherichia coli (6.5%) and Pseudomonas aeruginosa (1.7%). There was no severe toxicity or hypersensitivity.
Conclusion: Compared to oral decontamination and chemoprophylaxis, an intravenous prophylactic regimen as described above could be an effective and well-tolerated approach in prevention of bacterial infections and related complications, with a higher acceptance in recipients of bone marrow or stems cell grafts. Further evaluation in comparison with fluoroquinolone prophylaxis regarding efficacy, development of resistances as well as cost-benefit analyses is warranted.