Efficacy and safety of tigecycline monotherapy versus combination therapy for the treatment of hospital-acquired pneumonia (HAP): a meta-analysis of cohort studies

The broad spectrum antibiotic tigecycline shows promising efficacy against many multiple drug resistant (MDR) pathogens. However, its clinical efficacy in the treatment of hospital-acquired pneumonia (HAP) is unclear. Several studies have reported on the treatment failures of tigecycline monotherapy, suggesting that it may not be sufficient to control severe infections. Combination therapy has become an option to treat MDR bacterial infections. We conducted a literature search using PubMed, Cochrane Library, Embase, Elsevier and the Web of Knowledge databases up to 29 February 2017 to identify relevant published studies. Studies were considered eligible if they were a cohort study that assessed mortality and the safety of tigecycline monotherapy versus combination therapy with other antimicrobial agents for HAP. The primary outcome was treatment mortality rate, while the secondary outcomes were adverse events. Meta-analysis was done using fixed-effects models. Five trials were included. The monotherapy tigecycline had a higher mortality compared to the combination therapy group. There was a significant difference for the treatment of HAP. However, two prospective cohort studies showed that there was no significant difference in mortality rate between the tigecycline monotherapy and the tigecycline combination therapy. Three retrospective cohort studies showed that tigecycline monotherapy had a high mortality rate. Tigecycline combination therapy efficiently treats HAP. There is a great need for well-designed studies to evaluate the effectiveness and safety of combination therapies as they compare to tigecycline monotherapy.