Doxycycline for Multidrug-Resistant Gram-Negative Bacterial Infection Treatment: A Scoping Review

Multidrug-resistant bacterial infections limit available therapeutic options. Doxycycline is an old antibiotic from the tetracycline class that exhibits a wide antibacterial action, including Gram-negative bacteria (GNB), and could be an alternative for the treatment of multidrug-resistant (MDR) Enterobacteriaceae. The study aimed to systematically identify, evaluate, and summarize the results of studies related to outcomes of treatments for MDR-GNB infections in patients treated with doxycycline.

This review was conducted in four databases during weeks 41-52 of 2022: PubMed, Medline, Scopus, and Web of Science, from the earliest year available on each database to December 2022. Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines were followed in conducting this study, and PICO was used for the research question of this review.

This scoping review found 8 retrospective studies that included 59 patients. Of these, 69% were treated for ventilator-associated pneumonia (VAP), 27% for urinary tract infections, 2% for bloodstream infections, and 2% for wound infections, both of which were associated with VAP. The usual dosage of doxycycline was 100 mg intravenously or orally. Clinical and microbiologic improvements were achieved in 81.3% and 87% of all patients, respectively. The mortality rate was 17.3% and was exclusively due to VAP.

Doxycycline showed promising results in this review; however, randomized clinical trials or prospective cohorts are recommended to demonstrate the efficacy of doxycycline in the treatment of MDR infections with GNB.