Comparison of colistin monotherapy and non-colistin combinations in the treatment of multi-drug resistant Acinetobacter spp. bloodstream infections: A Multicenter retrospective analysis

Abstract

Objectives:To compare the efficacy of colistin (COL) monotherapy versus non-COL based combinations in the treatment of bloodstream infections (BSIs) due to multidrug resistant Acinetobacter spp.(MDR-A).Materials and Methods:Retrospective data of 107 MDR-A BSI cases from 27 tertiary centers in Turkey were included.Primary End-Point:14-day mortality.Secondary End-Points:Microbial eradication and clinical improvement.Results:Thirty-six patients in the COL monotherapy (CM) group and 71 in the non-COL based combinations (NCC) group were included in the study. Mean age was 59.98 ± 20 years (range: 18–89) and 50.5% were male. Median duration of follow-up was 40 days (range: 9–297). The 14-day survival rates were 52.8% in CM and 47.23% in NCC group (P = 0.36). Microbiological eradication was achieved in 69% of CM and 83% of NCC group (P = 0.13). Treatment failure was detected in 22.9% of cases in both CM and NCC groups. Univariate analysis revealed that mean age (P = 0.001), Charlson comorbidity index (P = 0.03), duration of hospital stay before MDR-A BSI (P = 0.04), Pitt bacteremia score (P = 0.043) and Acute Physiology and Chronic Health Evaluation II score (P = 0.05) were significant in terms of 14-day mortality. Advanced age (P = 0.01) and duration of hospital stay before MDR-A BSI (P = 0.04) were independently associated with 14-day mortality in multivariate analysis.Conclusion:No significant difference was detected between CM and non-COL based combinations in the treatment of MDR-A BSIs in terms of efficacy and 14-day mortality.

Treatment of Infections by OXA-48-Producing Enterobacteriaceae

“…A lack of adequate detection of OXA-48-producing strains was noted in this case series, attributed to low-level resistance to carbapenems and a lack of additional ESBLs, which may have contributed to the higher mortality rate. In bloodstream infections due to OXA-48-producing Enterobacteriaceae, a non-colistin-based combination regimen was found to be an independent risk factor for death in one study (67). When colistin was used, the survival rates were not significantly different when it was combined with either a carbapenem, a aminoglycoside, or a broad-spectrum cephalosporin in the setting of bacteremia (27).…”

“…When colistin was used, the survival rates were not significantly different when it was combined with either a carbapenem, a aminoglycoside, or a broad-spectrum cephalosporin in the setting of bacteremia (27). Interestingly, colistin has been reported as the least effective when used as a monotherapy (67).…”

“…No difference was noted between dual and triple-therapy regimens. Another study reported greater survival and microbiological cure of patients with OXA-48-producing Enterobacteriaceae bacteremia than in those treated with a single agent; however, this was attributed to greater source control and catheter removal (67). Despite a theoretical benefit, there are no clinical data to support the notion that combination therapy reduces the emergence of resistance (63).…”

Intravenous polymyxins: Revival with puzzle

“…In an early prospective cohort study, it's indicated that colistin appeared to be as safe and as effective as other antimicrobials for treatment of sepsis caused by A. baumannii and Pseudomonas aeruginosa (P. aeruginosa) in critically ill patients (4). Balkan, II, et al also found that there was no significant difference between colistin monotherapy and non-colistin based combinations in the treatment of MDR-Acinetobacter spp BSIs in terms of efficacy and 14-day mortality (37). But a larger sample size study discovered that colistin was less effective and more toxic than …”

“…intravenous polymyxins alone in MDR GNB infections, most of which were pneumonias. It's indicated that the mortality ranged from 0% to 74.3% (4,21,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37), clinical response (cure and improvement) rate 7-82.1%, and microbiological eradication 27.3-73.9% (24,(33)(34)(35)(36)(37)(38). In respect to the colistin only susceptible strains, it's reported that the mortality in hospitals of intravenous colistin monotherapy was 50% (16/32) (Figure 2), 11 patients died in Intensive Care Unit (ICU) (39), and clinical cure was obtained in 82.1% of infectious episodes (23/28) and bacteriological clearance was achieved in 73.9% (17/23) of the cured infectious episodes (38).…”