Aminoglycoside or Polymyxin Monotherapy effective in treatment of complicated UTI

The spread of multidrug-resistant gram-negative bacteria (GNB) is a global issue. Pseudomonas aeruginosa is especially concerning because of its amazing ability to build resistance. Pseudomonas aeruginosa (PA) infections that are XDR are difficult to treat.

According to a new trial, aminoglycosides or polymyxin monotherapy demonstrated high effectiveness and safety in treating cUTI caused by XDR-PA.

This study was conducted by Inmaculada López Montesinos and team with the objective to assess the efficacy of aminoglycosides or polymyxin monotherapy vs other antibiotic regimens (aztreonam, ceftolozane-tazobactam, ceftazidime-avibactam carbapenems, or ceftazidime, cefepime) in complex urinary tract infections (cUTI) caused by XDR-PA. The findings of this study were published in Infectious Disease and Therapy on 3rd December, 2021.

From 2010 through 2019, a study was conducted in a tertiary care hospital. All consecutive adult patients with XDR-PA urine cultures and cUTI were evaluated retrospectively. According to Magiorakos et al., the XDR phenotype was defined. In multivariate studies and for matching, a propensity score was utilized as a covariate. The primary outcome was early clinical failure and therapy discontinuation (EOT). The primary secondary outcomes were death at 30 and 90 days, microbiological clearance, and antibiotic-related adverse effects.

The results stated as follow:

1. 101 of the 465 episodes screened were included in the study, and 48% were treated with aminoglycoside or colistin monotherapy.

2. The majority of XDR-PA were completely susceptible to colistin and amikacin (43%).

3. Patients who received antibiotics other than aminoglycosides or polymyxin monotherapy were more likely to develop hematologic malignancy, a higher SOFA score, and bacteremia.

4. Monotherapy with aminoglycosides or colistin was not linked with poorer results in multivariate models adjusted by propensity score.

5. After propensity score matching, 28 episodes were matched in each treatment group. With aminoglycosides or polymyxin monotherapy, the adjusted odds ratios for early clinical failure and at EOT were 0.53 and 1.29, respectively.

6. Aminoglycoside or colistin monotherapy was not related with increased 30-day or 90-day mortality, nor was it connected with a lack of microbiological clearance.

7. In terms of nephrotoxicity, no statistically significant changes were discovered.

8. Only in the "other antibiotic regimens" group (n = 6, 11.3 percent) was Clostridioides difficile infection found.

In conclusion, When compared to combination or other antibiotic regimens, the findings of this study almost confirmed that amikacin or CMS monotherapy has no negative influence on the outcomes of complex UTIs caused by XDR PA. Given their clinical and environmental implications, these findings may be valuable for antibiotic stewardship programs. However, further research is needed to validate these findings, particularly in more seriously sick individuals.

Reference:

López Montesinos I, Gómez-Zorrilla S, Palacios-Baena ZR, Prim N, Echeverria-Esnal D, Gracia MP, Montero MM, Durán-Jordà X, Sendra E, Sorli L, Guerri-Fernandez R, Padilla E, Grau S, Horcajada JP; PROA PSMAR group. Aminoglycoside or Polymyxin Monotherapy for Treating Complicated Urinary Tract Infections Caused by Extensively Drug-Resistant Pseudomonas aeruginosa: A Propensity Score-Adjusted and Matched Cohort Study. Infect Dis Ther. 2021 Dec 3. doi: 10.1007/s40121-021-00570-z. Epub ahead of print. PMID: 34860333.