New Perspectives on Antimicrobial Agents: Imipenem-Relebactam

Area of Science:

• Pharmacology
• Infectious Diseases
• Microbiology

Background:

• Imipenem (IMI)/cilastatin/relebactam (REL) is a novel β-lactam/β-lactamase inhibitor combination.
• Relebactam inhibits Ambler class A and C β-lactamases, expanding activity against resistant Gram-negative pathogens.
• Approved for hospital-acquired bacterial pneumonia, ventilator-associated bacterial pneumonia, complicated urinary tract infections, and complicated intra-abdominal infections when alternatives are limited.

Purpose of the Study:

• To review published literature on I/R, focusing on its characteristics compared to other recently approved β-lactams.
• To evaluate the efficacy of I/R against carbapenem-resistant non-Morganellaceae Enterobacterales (CR-NME) and difficult-to-treat (DTR) Pseudomonas aeruginosa.

Main Methods:

• Literature review of published studies on imipenem/cilastatin/relebactam.
• Analysis of microbiologic activity and clinical data against resistant Gram-negative pathogens.
• Comparative assessment with other novel β-lactam agents.

Main Results:

• Available data support I/R use for CR-NME and DTR P. aeruginosa infections.
• I/R retains activity against some isolates resistant to newer β-lactams, and vice versa.
• Susceptibility testing is recommended for optimal treatment selection.

Conclusions:

• I/R is a potential treatment for CR-NME and DTR P. aeruginosa infections where benefits outweigh risks.
• Further comparative PK/PD and clinical studies are needed to define I/R's optimal role.
• I/R demonstrates a valuable role in managing infections caused by highly resistant Gram-negative bacteria.