A Comparative Study of Piperacillin-Tazobactam With and Without Vancomycin as Empirical Therapy for Febrile Neutropenic Patients With Solid Tumor Malignancies

BACKGROUND: The objective of this study was to evaluate the outcomes, mortality and toxicity associated with piperacillin-tazobactam (PT) and the addition of vancomycin (VM) to the empirical treatment of febrile neutropenic cancer patients. METHOD: A retrospective study on adult febrile neutropenic patients who were admitted between September 2008 and May 2013 with solid tumor malignancies was conducted at King Fahad Specialist Hospital Dammam, Saudi Arabia. RESULTS: Out of 86 febrile neutropenic patients, 60 patients were treated with PT group and 26 patients were with PT + VM group. The two groups were comparable in terms of outcome, mortality, nephrotoxicities and hepatotoxicities. The median duration of neutropenia in PT treatment group was 4 days (range 1 - 10) in the female and 7 days (range 1 - 13) in males while in PT + VM 6 days (range 1 - 5) in female and 7.5 days (range 1 - 6) in male with significance P = 0.007. There was no significant difference in terms of duration of fever and length of stay between the two treatment groups. There were no deaths reported during treatment in both groups. In PT, the microbial eradication was 27/40 (67.5%) patients (14/27 (51.9%) of female and 13/27 (48.1%) of male)), whereas it was 13/40 (32.5%) patients (9/13 (69.2%) of female and 4/13 (30.8%) of male)) in PT + VM group. Overall, there was no significant difference in terms of microbiological eradication between the two groups (OR: 1.22; 95% CI: 0.486 - 3.072; X(2) stat: 0.182; P = 0.67). Response to therapy in clinically defined infections was higher 16/23 (69.56%) in PT treatment group than 7/23 (30.44%) in PT + VM group. But there was no significant difference between the two treatment groups in terms of clinically defined infections (OR: 1.013; 95% CI: 0.359 - 2.862; X(2) stat: 0.001; P = 0.98). There was no significant difference in renal and liver functions between the two groups in terms of serum creatinine level and clearance, alkaline phosphate and alanine tranferase and gama glutamyl tranferase. The most commonly isolated organisms were Escherichais coli (eighteen isolates), Staphylococcus aureus (seven isolates), Streptococcus spp (six isolates) and Klebsiella pneumonia (four isolates). The overall success rate was similar in both treatment arms and treatment was well tolerated, with no severe adverse reactions reported. CONCLUSION: Although the addition of VM might provide an additional value for coverage of gram-positive pathogens. This study demonstrates that there was no significant difference in terms of response rate in both treatment groups, which could be due to the low local methicillin-resistant Staphylococcus aureus (MRSA) rates and other resistant gram-positive organisms at our institution, stressing the importance of local antibiograms in developing empirical neutropenic fever protocols.