Efficacy of Oral Ciprofloxacin Prophylaxis in BMT Recipients: A Case-Control Study.

Bacterial infections remain a major source for morbidity and mortality in peripheral stem cell (PSC) and bone marrow (BM) transplant recipients. Despite the considerable number clinical trials, there is still no consensus of opinions for the use of antibiotic prophylaxis. In order to analyze the impact on bacteraemia of withdrawing ciprofloxacin prophylaxis from PSC and BM transplant patients during neutropenia, a total of 617 records were reviewed and found suitable for analysis; 310 autologous and 307 allogenic from Jan 4, 2001 to Dec 27, 2005. Ciprofloxacin was used as a prophylactic measure among all these autologous and allogenic stem cell and bone marrow transplant patients until January 31, 2004. As of February 1, 2004, it was no longer given as a prophylactic measure. Patient characteristics were found similar in the group with ciprofloxacin prophylaxis and the group without ciprofloxacin prophylaxis. Resistant bacteraemia was defined as either ciprofloxacin resistant gram negative bacteria, or VRE, or MRSA. For the analysis the two proportions were compared with a log binomial regression model using generalized estimating equations to account for the lack of independence in the observations. Bacteraemia was the dependent variable, and time periods prior transplant year and year of transplant were included as independent variables. The model was used to generate variance estimates for the proportions, and to check for confounding. Prior transplant year or year of transplant were not confounding variables so, there was no need for adjusted estimates. The analysis shows that the relative risk of developing bacteraemia in the autologous and allogenic groups after ciprofloxacin prophylaxis was discontinued compared with when it was used routinely in the same group was 0.6 (95% CI: 0.2–1.6) and 0.8 (95% CI: 0.4–1.6) respectively. The change in the proportion of patients developing bacteraemia was not statistically significant .The estimation of 100 day-survival from transplant was determined by time period using the Kaplan-Meier Method. The analysis was limited to patients who did not have a prior transplant. In the autologous group, no difference was found when ciprofloxacin prophylaxis was used routinely (n=155): 93.6 (95% CI: 88.3–96.5) versus ciprofloxacin prophylaxis not used (n=112): 94.1 (95% CI: 88.1–97.2). Likewise, no difference was found in the allogenic group when ciprofloxacin prophylaxis used routinely (n=135): 88.9 (95% CI: 82.3–93.2) versus Ciprofloxacin prophylaxis not used (n=106): 87.7 (95% CI: 79.8–92.7). The incidence of bacteraemia with resistant organisms was not statistically significant in both groups. In the autologous groups the incidence was 2 (18.2%) with ciprofloxacin prophylaxis and 1 (20.0%) without ciprofloxacin prophylaxis. In the allogenic group the incidence was 5 (2.8%) with ciprofloxacin prophylaxis and 3 (2.3%) without ciprofloxacin prophylaxis . Overall, in our institution, stopping ciprofloxacin prophylaxis did not significantly affect the incidence of bacteraemia, the 100 days all-cause mortality or the incidence of antibiotic resistant bacteraemia among allogenic and autologous transplant patients. As a result, ciprofloxacin prophylaxis has been suspended and a surveillance program has been adopted.