Background Use of tigecycline in treating MDR Acinetobacter baumannii (MDRAB) remains controversial. Objectives To comprehensively assess the safety and efficacy of tigecycline in pneumonia caused by Acinetobacter baumannii. Methods PubMed, Embase, Web of Science and Cochrane library databases were searched up to 12 March 2019. Studies were included if they compared tigecycline-based regimens with other antibiotic regimens for treating AB pulmonary infections and we pooled the clinical outcomes, microbiological response, adverse events or mortality. Results One prospective study and nine retrospective studies were included in this meta-analysis. The results showed similar clinical cure rates (OR = 1.04, 95% CI = 0.60–1.81; P = 0.89) and mortality rates (OR = 1.11, 95% CI = 0.65–1.89; P = 0.71) comparing tigecycline groups with the control groups. However, a significantly lower microbiological eradication rate was found in the tigecycline groups (OR = 0.43, 95% CI = 0.27–0.66; P = 0.0001). Incidence of nephrotoxicity in tigecycline-based regimens was significantly lower than in colistin-based regimens (OR = 0.34, 95% CI = 0.16–0.74, I2 = 35%, P = 0.006). There were no randomized controlled trials (RCTs) included; incomplete safety data and regional bias caused by the majority of the studies originating in China are the main limitations of this meta-analysis. Conclusions Tigecycline can be used for treating MDRAB pulmonary infections owing to efficacy similar to that of other antibiotics. Moreover, tigecycline did not show a higher risk of mortality. Considering the lower microbiological eradication rate for tigecycline, which is likely to induce antimicrobial resistance, well-designed RCTs for high-dose tigecycline in treating pneumonia caused by AB are still needed.

Background:The clinical significance of using vancomycin loading dose remains controversial. A systematic review and meta-analysis were performed to assess the clinical efficacy and safety of vancomycin loading dose in the treatment of infections.Methods:The Pubmed, Embase, Web of Science, and Cochrane Library databases were searched from their inception up to 5 May 2019. Randomized controlled trials (RCTs) and other observational studies were included if they provided clinical outcomes or trough concentrations of vancomycin loading dose (20–30 mg/kg) and conventional-dose (10–20 mg/kg) in the treatment of infections. Achievement of therapeutic concentration (serum trough concentrations of vancomycin reached 15–20 mg/L before the second dose), clinical response (clinical improvement or culture-negative), nephrotoxicity (serum creatinine increase ≥0.5 mg/dL or ≥50% increasing from the baseline), other adverse events (including pruritus, flushing, rash, and/or red man syndrome), and mortality were analyzed. Heterogeneity was identified using the Cochrane I2 statistic, and P-value <.10 or I2-values >50% indicated significant heterogeneity. Pooled estimates of the intervention effects were determined by the odds ratios (ORs) and 95% confidence intervals (CIs) in Review Manager program, version 5.3.5.Results:Two RCTs and 7 cohort studies including 2816 infected patients were selected for the analysis, in which serum trough concentrations of vancomycin following the use of vancomycin loading dose or other outcomes were available. Loading dose group had a significantly higher compliance rate of serum trough concentration of 15 to 20 mg/L (OR = 3.06; 95% CI = 1.15–8.15; P = .03) and significantly lower incidence of nephrotoxicity (OR = 0.59, 95% CI = 0.40–0.87; P = .008; I2 = 29%) compared with control group. No significant difference was noted between loading dose group and control group in terms of other adverse events and clinical response (OR = 1.98, 95% CI = 0.80–4.93; P = .14; I2 = 0%). The use of vancomycin loading doses in patients can indeed increase the achievement of therapeutic concentration.Conclusion:Vancomycin loading dose increases the achievement of therapeutic concentration without bringing extra risk of nephrotoxicity. However, well-designed large-scale RCTs remain needed to validate the clinical efficacy of vancomycin loading dose and to further evaluate other adverse reactions and mortality.PROSPERO registration number CRD42018093927