Evidence Hub

Overcoming resistance barriers: Using the salvage therapy of Ceftazidime-Avibactam and Aztreonam for difficult-to-treat gram-negative infections at a tertiary care hospital in Karachi-A retrospective cohort pilot

Sarfaraz S, Zafar SM, Siddiqui NA, Hanif MH, Hussain Z

Pakistan journal of medical sciences, 2026

21 participants

Abstract

Background & objective: Rise of carbapenem resistance poses a major global health challenge, particularly in Pakistan where treatment options for Gram-negative carbapenem-resistant Enterobacteriaceae (CRE), are extremely limited. Last-resort agents such as colistin, tigecycline, and fosfomycin are constrained by toxicity and emerging resistance. Aztreonam, active against metallo-β-lactamase-producing organisms, is often unavailable or unaffordable. At Indus Hospital and Health Network (IHHN), Ceftazidime-Avibactam (CAZ-AVI) combined with Aztreonam (ATM) was used as salvage therapy between September 2023 and September 2024. The study aimed to evaluate outcomes of using CAZ-AVI with Aztreonam in patients with CRE.

Methodology: This retrospective cohort study was conducted at IHHN from September 2023 to September 2024. Patients with carbapenem-resistant infections treated with CAZ-AVI + ATM were included, excluding CRAB. Due to limited availability of ATM in Pakistan, only 21 patients received this regimen, enabling it as pilot study. Clinical and microbiological data were extracted from HMIS and analyzed using SPSS.

Results: Among 21 treated patients, the regimen yielded an in-hospital survival rate of 85.7% and clinical improvement in 83% of survivors, with minimal adverse effects. These findings suggest meaningful clinical benefit in patients with limited therapeutic options.

Conclusion: CAZ-AVI plus ATM appears to be an effective salvage therapy for carbapenem-resistant…

How strong is the evidence?

Evidence Hub reads this as a cohort study, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 21 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free