Combination Versus Monotherapy for Carbapenem-Resistant Acinetobacter Species Serious Infections: A Prospective IPTW Adjusted Cohort Study

• Published in: Infectious diseases and therapy 2024-11, Vol.13 (11), p.2351-2362
• Main Authors: Manesh, Abi, George, Mithun Mohan, Palanikumar, Prasannakumar, Nagaraj, V., Bhanuprasad, Kundakarla, Krishnan, Ramya, Nivetha, G., Lal, Binesh, Triveni, K. Rajitha, Gautam, Priyanka, George, Biju, Kulkarni, Uday, Mathews, Vikram, Subramani, K., Rao, Shoma, Chacko, Binila, Zachariah, Anand, Sathyendra, Sowmya, Hansdak, Samuel George, Abraham, Ooriapadickal Cherian, Iyadurai, Ramya, Karthik, Rajiv, Peter, John Victor, Mo, Yin, Veeraraghavan, Balaji, Varghese, George M., Paterson, David Leslie
• Format: Article
• Language: English
• Subjects: Acinetobacter; Antibiotics; Bacterial pneumonia; Care and treatment; Combination therapy; Comparative analysis; CRAB infections; Health aspects; Imipenem; India; Infections; Infectious Diseases; Internal Medicine; Medical research; Medicine; Medicine & Public Health; Medicine, Experimental; Mortality; Observational studies; Original Research; Pneumonia; Polymyxins; Sulbactam
• ISSN: 2193-8229; 2193-6382
• DOI: 10.1007/s40121-024-01042-w

Introduction International guidelines recommend definitive combination antibiotic therapy for the management of serious infections involving carbapenem-resistant Acinetobacter (CRAB) species. The commonly available combination options include high-dose sulbactam, polymyxins, tetracyclines, and cefiderocol. Scanty prospective data exist to support this approach. Methods Patients with CRAB bacteraemia, ventilator-associated pneumonia (VAP), or both were categorized based on whether they received combination therapy or monotherapy. The 30-day mortality was compared between the two groups. Inverse probability treatment weighting (IPTW) was done using propensity score (PS) for a balanced comparison between groups. Results Between January 2021 and May 2023, of the 161 patients with CRAB bacteraemia ( n  = 55, 34.2%), VAP ( n  = 46, 28.6%), or both ( n  = 60, 37.3%) who received appropriate intravenous antibiotic therapy, 70% (112/161) received monotherapy, and the rest received combination therapy. The overall 30-day mortality was 62% (99/161) and not different ( p  = 0.76) between the combination therapy (31/49, 63.3%) and monotherapy (68/112, 60.7%) groups. The propensity score matching using IPTW did not show a statistical difference ( p  = 0.47) in 30-day mortality for receiving combination therapy with an adjusted odds ratio (OR) P of 1.29 (0.64, 2.58). Conclusion Combination therapy for CRAB infections needs further study in a randomised controlled trial, as this observational study showed no difference in 30-day mortality between monotherapy and combination therapy.