Patients with compromised immune systems are at much greater risk of developing bloodstream infections, a complication associated with significant morbidity and mortality. Treatment for these patients includes hematopoietic stem cell transfusion (HSCT), and  routine prophylactic antimicrobial therapy should be given to reduce the incidence of these complications. Guidelines recommend prophylaxis starting on day 0 of the transfusion until resolution of neutropenia/symptoms. The two major antibiotics used for this are levofloxacin and ciprofloxacin; both having similar gram-negative coverage, they have marked differences in their gram-positive coverage. Levofloxacin has the advantage in this regard, with enhanced gram-positive activity.

Until now there has not been a direct comparison between these two agents in HSCT patients,  therefore a recent retrospective cohort study was undertaken comparing multiple myeloma patients treated with autologous HSCT who received
ciprofloxacin (500mg PO BID) versus levofloxacin (500 mg PO daily). Levofloxacin treated patients were enrolled over the year 2015, while the ciprofloxacin patients were treated from 1/2007-5/2008. All patients also received acyclovir and fluconazole.

297 patients were enrolled in the study (143 levofloxacin, 154 ciprofloxacin). Patient characteristics were similar for both groups apart from age. Both groups received treatment for a similar duration (9 days ciprofloxacin, 10 days levofloxacin). There was a much higher incidence of bloodstream infections (24/154) in the ciprofloxacin-treated group compared to those given levofloxacin (10/143) p=0.03. Further analysis showed that more of these bloodstream infections were caused by gram-positive pathogens (ciprofloxacin (21/154) versus levofloxacin (8/143); p<0.01). There was no significant difference in the number of gram-negative infections between the ciprofloxacin and levofloxacin groups.

The authors concluded that these results demonstrated a clinical advantage for levofloxacin, as it was associated with significantly lower rate of bloodstream infections, especially when preventing infections caused by gram-positive pathogens, which are the most frequently reported organisms identified during HSCT. In particular viridans group streptococci are the most commonly identified pathogens, a greater problem for ciprofloxacin, as resistance rates of up to 40% have been reported for this agent. These results confirm that levofloxacin is a more effective prophylactic agent in HSCT patients with multiple myeloma  and that this retrospective study should be supplemented by a randomised, prospective trial to investigate this further.

PMID: 29080369

Clin Transplant. 2017 Oct 28. doi: 10.1111/ctr.13145. [Epub ahead of print]

Source: https://www.ncbi.nlm.nih.gov/pubmed/29080369?dopt=Abstract