Clinical experience of tigecycline treatment in infections caused by extensively drug-resistant Acinetobacter spp

Tigecycline-Containing Regimens and Multi Drug-Resistant Acinetobacter baumannii: A Systematic Review and Meta-Analysis

Introduction: The use of tigecycline (TG) for the treatment of Acinetobacter baumannii is controversial. In this systematic review and meta-analysis, we aimed to better explore the safety and efficacy of TG for the treatment of multi drug-resistant (MDR) Acinetobacter. Methods: We searched PubMed/MEDLINE, Scopus, Cochrane Central, and Web of Science to identify studies reporting the clinical and microbiological efficacy and safety of regimens containing TG in patients with drug susceptibility testing (DST)-confirmed MDR A. baumannii, published until December 30, 2022. Observational studies were included if they reported clinical and microbiological efficacy of TG-based regimens. The Newcastle-Ottawa Scale (NOS) and Joana Briggs Institute (JBI) critical appraisal tool were used to assess the quality of included studies. Results: There were 30 observational studies, of which 19 studies were cohort and 11 studies were single group studies. Pooled clinical response and failure rates in the TG-containing regimens group were 58.1 (95% confidence interval [CI] 49.2-66.6) and 40.2 (95% CI 31.1-50.0), respectively. The pooled microbiological response rate was 32.1 (95% CI 19.8-47.5), and the pooled all-cause mortality rate was 41.1 (95% CI 34.1-48.4). Pooled clinical response and failure rates in the colistin-based regimens group were 52.7 (42.7-62.5) and 43.1 (33.1-53.8), respectively. The pooled microbiological response rate was 42.9 (16.2-74.5), and the pooled all-cause mortality rate was 34.3 (26.1-43.5). Conclusions: According to our results, the efficacy of the TG-based regimen is the same as other antibiotics. However, our study showed a high mortality rate and a lower rate of microbiological eradication for TG compared with colistin-based regimen. Therefore, our study does not recommend it for the treatment of MDR A. baumannii. However, this was a prevalence meta-analysis of observational studies, and for better conclusion experimental studies are required.

Risk Factors for Tigecycline-Associated Hepatotoxicity in Patients in the Intensive Care Units of Two Tertiary Hospitals: A Retrospective Study

Tigecycline is a broad-spectrum antibacterial agent. As the incidence of multidrug-resistant bacterial infections has increased in intensive care units (ICUs) over the past decades, tigecycline is often used in ICUs. Information about tigecycline-associated hepatotoxicity in ICU patients is limited. To investigate the potential risk factors for tigecycline-associated hepatotoxicity in ICU patients, 148 patients from two centers who had received tigecycline for at least 4 days were retrospectively analyzed. Hepatotoxicity was classified according to the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE 5.0) grading system. As a result, 33.8% of patients experienced hepatotoxicity events in the ICU. The multivariate analysis showed that an albumin concentration <25 g/L at baseline [odds ratio (OR) 3.714, 95% confidence interval (CI), 1.082-12.744, P = 0.037) and treatment duration (OR 1.094, 95% CI, 1.032-1.160, P = 0.003) were significantly correlated with tigecycline-associated hepatotoxicity. The median time to onset of hepatotoxicity was 8.0 days. The median duration ICU stay and the in-hospital mortality rate were not different between the hepatotoxicity group and the nonhepatotoxicity group [33.5 days (interquartile range (IQR) 21.0-72.0) vs. 31.0 days (IQR 21-62.5), P = 0.850; 38.0% vs. 43.8%, P = 0.504]. Therefore, close monitoring of liver function is recommended for patients with baseline albumin concentrations < 25 g/L or for patients who receive tigecycline therapy for more than 8 days. This article is protected by copyright. All rights reserved.

Outcomes and prognostic factors of tigecycline treatment for hospital-acquired pneumonia involving multidrug-resistant Acinetobacter baumannii

Objective: To compare outcomes and prognostic factors of tigecycline (TC)-based treatment with those of other antibiotic-based treatments in the treatment of hospital-acquired pneumonia caused by multidrug-resistant Acinetobacter baumannii (MDRAB).

Methods: A retrospective analysis of data was performed from all patients ≥18 years who were treated in the ICU at Xiangya Hospital, Changsha, China (January 2016 to June 2017) with hospital-acquired pneumonia involving monomicrobial MDRAB. Patients were separated into TC and non-TC groups.

Results: Of 86 MDRAB-positive patients, 59 were in the TC group and 27 were in the non-TC group. The 28-day death rates were not significantly different between the two groups, but the TC group had significantly more patients with a good clinical prognosis than the non-TC group. Although prognostic markers for a poor clinical response were sepsis, procalcitonin concentration and APACHE II scores, TC therapy was found to be a protective factor.

Conclusions: TC based therapy was associated with a positive clinical response in the treatment of MDRAB caused hospital-acquired pneumonia. Further studies are required to confirm our results.

Efficacy and safety of tigecycline in treatment of pneumonia caused by MDR Acinetobacter baumannii: a systematic review and meta-analysis

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.

Effect of pharmacokinetic/pharmacodynamic ratio on tigecycline clinical response and toxicity in critically ill patients with multidrug-resistant Gram-negative infections

Introduction:

The information about the pharmacokinetics and optimal dose of tigecycline in critically ill patients with severe underlying diseases is limited and controversial. In this study, we evaluate the pharmacokinetic parameters of tigecycline in critically ill patients with multidrug-resistant Gram-negative infection and explore the association between the pharmacokinetic/pharmacodynamic ratio and treatment response.

Methods:

A prospective study was designed including critically ill patients treated with tigecycline for multidrug-resistant Gram-negative infections. Blood samples were collected at day 3–5 of treatment, and pharmacokinetics parameters were evaluated using NONMEM^® software. Relationship between area under the free concentration–time curve and minimum inhibitory concentration ratio (fAUC/MIC) and treatment failure was evaluated. Association between tigecycline fAUC and hepatobiliary toxicity was also investigated.

Results:

Twenty-five critically ill patients were included in the study. In the pharmacokinetic model, weight and total bilirubin level were found to be significant predictors of tigecycline clearance. Fifteen (60.0%) patients achieved an fAUC/MIC ratio >4.5, seven (28.0%) an fAUC/MIC > 6.96 and only three (12.0%) an fAUC/MIC > 17.9. No differences in fAUC/MIC ratio were obtained between those patients with and without clinical failure (5.28 (IC95%: 2.57–7.94) vs 8.71 (3.57–13.84)). fAUC values were higher in those patients who suffered hepatobiliary disorders (7.63 (3.93–11.34) vs 17.63 (7.85–26.28) mg/L/h).

Conclusion:

An important percentage of critically ill patients with multidrug-resistant Gram-negative infection treated with tigecycline do not achieve an appropriate pharmacokinetic/pharmacodynamic value. Tigecycline fAUC seems to be associated with hepatobiliary disorders in this study population. The effect of fAUC/MIC ratio on clinical response remains unclear.

Epidemiology and treatment of antimicrobialresistant gram-negative bacteria in Korea

Antimicrobial resistance is becoming one of the greatest challenges to public health worldwide. Infections by antimicrobial-resistant organisms could result in the failure of treatment, increased medical costs, prolonged hospital stays, and an increased socioeconomic burden. Antimicrobial usage in Korea remains heavy, even after much effort to reduce their use. According to the Korean antimicrobial resistance surveillance system, the resistance rates of many bacteria are increasing. The resistance rate of Acinetobacter baumannii to imipenem in Korea increased to 85% in 2015, representing a major public threat. The reports of increased carbapenem resistance in Enterobacteriaceae are worrisome. More importantly, some carbapenem-resistant Enterobacteriaceae may result from the production of carbapenemases, which break down carbapenems. There are relatively few treatment options for extensively drug-resistant A. baumannii and carbapenem-resistant Enterobacteriaceae. Most reports are retrospective observational studies. Because there are little published data from randomized controlled trials, more data assessing antimicrobial treatment for extensively drug-resistant A. baumannii and carbapenem-resistant Enterobacteriaceae are needed to make treatment recommendations.

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.

Efficacy of intravenous tigecycline in patients with Acinetobacter complex infections: results from 14 Phase III and Phase IV clinical trials

Background

Acinetobacter infections, especially multidrug-resistant (MDR) Acinetobacter infections, are a global health problem. This study aimed to describe clinical outcomes in patients with confirmed Acinetobacter spp. isolates who were treated with tigecycline in randomized clinical trials.

Materials and methods

Data from 14 multinational, randomized (open-label or double-blind), and active-controlled (except one) Phase III and IV studies were analyzed using descriptive statistics.

Results

A total of 174 microbiologically evaluable patients with Acinetobacter spp. infections (including MDR infections) were identified, and 95 received tigecycline to treat community-acquired pneumonia (CAP), diabetic foot infections (DFIs), hospital-acquired pneumonia (HAP), complicated intra-abdominal infections (cIAIs), infections with resistant pathogens (RPs), or complicated skin and skin-structure infections. The rate of cure of tigecycline for most indications was 70%–80%, with the highest (88.2%) in cIAIs. The rate of cure of the comparators was generally higher than tigecycline, but within each indication the 95% CIs for clinical cure for each treatment group overlapped. For most Acinetobacter isolates, the minimum inhibitory concentration of tigecycline was 0.12–2 μg/mL, with seven at 4 μg/mL and one at 8 μg/mL. The cure rate by tigecycline was 50% (95% CI 12.5%–87.5% in CAP) to 88.2% (95% CI 66.2%–97.1% in cIAIs) for all Acinetobacter, and 72.7% (95% CI 54.5%–93.2% in HAP) to 100% (95% CI 25%–100.0% in cIAIs) for MDR Acinetobacter. For the comparators, it was 83.8% (95% CI 62.8%–95.9% in HAP) to 100% (95% CI 75%–100% in cIAIs and 25%–100.0% in RPs) and 88% (95% CI 66%–97% in HAP) to 100% (95% CI 25%–100% in cIAIs and 75%–100% in DFIs), respectively.

Conclusion

These findings suggest that with appropriate monitoring, tigecycline may be a useful consideration for Acinetobacter infections alone or in combination with other anti-infective agents when other therapies are not suitable.

Antimicrobial-resistant Pseudomonas aeruginosa and Acinetobacter baumannii From Patients With Hospital-acquired or Ventilator-associated Pneumonia in Vietnam

PURPOSE

Multidrug-resistant bacterial pathogens are becoming a significant problem worldwide. Acinetobacter baumannii and Pseudomonas aeruginosa are problematic multidrug-resistant pathogens. This multicenter study in Vietnam determined the level of resistance to antimicrobial agents used to treat A baumannii and P aeruginosa infections in this country.

METHODS

Five medical centers in Vietnam provided 529 P aeruginosa and 971 Acinetobacter species (904 A baumannii) isolates from patients with hospital-acquired or ventilator-associated pneumonia from 2012 to 2014. A central laboratory verified identification of the isolates and performed susceptibility testing using Clinical and Laboratory Standards Institute methods.

FINDINGS

Resistance to cephalosporins, β-lactam/β-lactamase inhibitors, carbapenems, and fluoroquinolones was >90% against A baumannii. Aminoglycosides had only slightly better activity, with amikacin resistance >80%. Only colistin (MIC90, ≤0.25 mg/L) and tigecycline (MIC90, 4 mg/L) had appreciable activity against A baumannii. Similar activity was observed among the β-lactams tested against P aeruginosa. Cefepime demonstrated the highest activity (60.1% susceptible), which was similar to doripenem (58.6% susceptible), the most active carbapenem tested. Amikacin was the most active aminoglycoside tested against P aeruginosa, with susceptibility of 81.7% compared with tobramycin (58.0%) and gentamicin (56.5%). Fluoroquinolones had limited activity against P aeruginosa with susceptibility to ciprofloxacin (55.0%). All P aeruginosa isolates had colistin MIC values ≤2 mg/L.

IMPLICATIONS

The data from this 3-year longitudinal study in Vietnam demonstrate that 2 of the most common nonfermentative gram-negative pathogens associated with hospital-acquired and ventilator-associated pneumonia are significantly resistant to most of the available treatment options and require combination therapies unless new antimicrobial agents become available.

Efficacy and Safety of Tigecycline for Patients with Hospital-Acquired Pneumonia

BACKGROUND

Tigecycline is an antibiotic agent with a broad spectrum, which has an antibacterial effect against many multidrug-resistant organisms. However, its clinical efficacy in the treatment of hospital-acquired pneumonia (HAP) is disputed.

MATERIALS AND METHODS

In this report, a systematic review and meta-analysis were conducted to evaluate the efficacy and safety of tigecycline for the treatment of HAP. The primary outcome was the rate of clinical cure, and the secondary outcomes were mortality and adverse events (AEs).

RESULTS

Four trials involving 1,234 patients were included. The standard-dose tigecycline and comparator groups did not differ significantly in their rates of clinical cure. However, high-dose tigecycline was more effective than standard-dose tigecycline or the comparators for the treatment of HAP. There was no significant difference in mortality between the standard-dose or high-dose regimen and the comparators. Although the safety profile of standard-dose tigecycline was similar to the comparators, the high-dose regimen exhibited more AEs compared with the other groups.

CONCLUSION

High-dose tigecycline is efficient for the treatment of HAP but is associated with more AEs.

A mouse model of Acinetobacter baumannii-associated pneumonia using a clinically isolated hypervirulent strain

Acinetobacter baumannii is an important emerging pathogen in health care-acquired infections and is responsible for severe nosocomial and community-acquired pneumonia. Currently available mouse models of A. baumannii pneumonia show poor colonization with little to no extrapulmonary dissemination. Here, we describe a mouse model of A. baumannii pneumonia using a clinical isolate (LAC-4 strain) that reliably reproduces the most relevant features of human pulmonary A. baumannii infection and pathology. Using this model, we have shown that LAC-4 infection induced rapid bacterial replication in the lungs, significant extrapulmonary dissemination, and severe bacteremia by 24 h postintranasal inoculation. Infected mice showed severe bronchopneumonia and dilatation and inflammatory cell infiltration in the perivascular space. More significantly, 100% of C57BL/6 and BALB/c mice succumbed to 10(8) CFU of LAC-4 inoculation within 48 h. When this model was used to assess the efficacy of antimicrobials, all mice treated with imipenem and tigecycline survived a lethal intranasal challenge, with minimal clinical signs and body weight loss. Moreover, intranasal immunization of mice with formalin-fixed LAC-4 protected 40% of mice from a lethal (100× 100% lethal dose) intraperitoneal challenge. Thus, this model offers a reproducible acute course of A. baumannii pneumonia without requiring additional manipulation of host immune status, which will facilitate the development of therapeutic agents and vaccines against A. baumannii pneumonia in humans.