Safety and efficacy of colistin alone or in combination in adults with Acinetobacter baumannii infection: A systematic review and meta-analysis

ABSTRACT This review comprehensively assessed the safety and efficacy of colistin alone or in combination in adults with Acinetobacter baumannii infection. PubMed, Embase and the Cochrane Library were searched from inception to March 2018 for studies evaluating colistin monotherapy compared with other antibiotic therapy or colistin-based combination therapy for the treatment of A. baumannii infection in adults. Efficacy outcomes were clinical response and microbiological cure. Safety outcomes were mortality and nephrotoxic adverse events. A total of 4 randomised controlled trials (RCTs) and 14 observational studies were identified, including 7 reporting colistin versus other antibiotics and 12 reporting colistin monotherapy versus colistin-based combination therapy. Overall clinical response, microbiological response and mortality did not differ significantly between colistin monotherapy versus other antibiotics. However, the incidence of nephrotoxicity was significantly higher in colistin monotherapy (OR = 2.50, 95% CI 1.05–5.98; P  = 0.04). No significant differences were detected in clinical response and >28-day mortality between colistin monotherapy and combination therapy. However, colistin-based combination therapy showed an increased microbiological response (OR = 0.49, 95% CI 0.32–0.74; P  = 0.0009) and decreased incidence of nephrotoxicity (OR = 1.66, 95% CI 0.99–2.78; P =0.05). In conclusion, colistin alone is as effective as other antibiotics for the treatment of A. baumannii infection but has a higher risk of nephrotoxicity. Colistin-based combination therapy demonstrated a microbiological benefit and no higher risk of nephrotoxicity compared with monotherapy. High-quality RCTs are still needed to confirm the beneficial role of colistin-based combination therapy.