The aim of this study was to compare the efficacy and safety of tigecycline, a newly developed glycylcycline antibiotic, with those of empirical antibiotic regimens which have been reported to possess good efficacy for complicated skin and skin structure infections (cSSSIs), complicated intra-abdominal infections (cIAIs), community-acquired pneumonia (CAP), and other infections caused by methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE CI ؍ 0.69 to 1.07, P ؍ 0.19). The incidence of adverse events in the tigecycline group was significantly higher than that in the other therapy groups with a statistical margin (for the modified intent-to-treat [mITT] population, OR ؍ 1.33, 95% CI ؍ 1.17 to 1.52, P < 0.0001), especially in the digestive system (mITT population, OR ؍ 2.41, 95% CI ؍ 1.67 to 3.46, P < 0.00001). No difference regarding all-cause mortality and drug-related mortality between tigecycline and the other regimens was found, although numerically higher mortality was found in the tigecycline group. This meta-analysis provides evidence that tigecycline monotherapy may be used as effectively as the comparison therapy for cSSSI, cIAIs, CAP, and infections caused by MRSA/VRE. However, because of the high risk of mortality, AEs, and emergence of resistant isolates, prudence with the clinical use of tigecycline monotherapy in infections is required.The threat of antimicrobial resistance has been identified as one of the major challenges facing public health, and antimicrobial resistance has increased rates of morbidity and mortality and socioeconomic costs. The rapid rate of microbial evolution underscores the urgent need for development of new agents that overcome existing mechanisms of resistance displayed by multidrug-resistant bacteria.Tigecycline is a first-in-class expanded-broad-spectrum glycylcycline. It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit but with a five times higher affinity than that for the tetracyclines (4). In vitro studies demonstrate that it has good activity against many commonly encountered respiratory bacteria, including multiple resistant Gram-positive, Gram-negative, anaerobic, as well as multidrug-resistant (MDR) pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant Enterococcus (VRE), penicillin-resistant Streptococcus pneumoniae (PRSP), and -lactamase-producing Haemophilus influenzae, among others (5). Tigecycline overcomes the two key tetracycline resistance mechanisms (efflux pumps and ribosomal protection) and is unaffected by other bacterial mechanisms of resistance, such as extended-spectrum -lactamases (32).Tigecycline was first approved for use for indications of complicated skin and skin structure infections (cSSSIs) and complicated intra-abdominal infections (cIAIs). Currently, it is approved for use for community-acquired pneumonia (CAP). It has also been found to be effective for the trea...