Treatment of Acinetobacter baumannii Urinary Tract Infections

First-Line Treatment Options

The American College of Physicians recommends carbapenems (imipenem, meropenem, doripenem) as first-line therapy for carbapenem-susceptible A. baumannii UTIs in areas with low rates of carbapenem resistance 1
For isolates susceptible to sulbactam (MIC ≤4 mg/L), the Infectious Diseases Society of America prefers ampicillin-sulbactam due to its better safety profile compared to polymyxins 3, 2

The Intensive Care Medicine society recommends administering ampicillin-sulbactam as a 4-hour infusion of 3g sulbactam every 8 hours (9-12g/day total) for isolates with MIC ≤4 mg/L 3, 1
The European Society of Clinical Microbiology and Infectious Diseases recommends imipenem 0.5-1g every 6 hours, and meropenem 2g every 8 hours, with caution for high doses associated with seizures 3
The Infectious Diseases Society of America recommends colistin (Polymyxin E) with a loading dose of 6-9 million IU followed by 9 million IU/day in 2-3 divided doses, with dose adjustment for renal dysfunction 3, 1

The American College of Physicians suggests treatment can generally be completed in 7 days for uncomplicated UTIs, and up to 14 days for complicated UTIs or those with systemic symptoms 2
Treatment duration should be guided by clinical response and resolution of symptoms, according to the Infectious Diseases Society of America 1

The European Society of Clinical Microbiology and Infectious Diseases recommends urinary catheter removal or replacement when possible, as catheterization is a risk factor for developing A. baumannii infections 3
For uncomplicated UTIs with susceptible isolates, monotherapy is generally sufficient, according to the American College of Physicians 1
For complicated UTIs or those with systemic symptoms, the Infectious Diseases Society of America considers combination therapy with two active agents for severe infections 1, 4

The Intensive Care Medicine society recommends monitoring renal function in patients receiving colistin, as nephrotoxicity occurs in up to 33% of patients 5, 2
Nephrotoxicity is higher with colistin (33%) compared to ampicillin-sulbactam (15.3%), according to the European Society of Clinical Microbiology and Infectious Diseases 3

The American College of Physicians advises against polymyxin-meropenem combination therapy for CRAB infections with high-level carbapenem resistance (MICs >16 mg/L) 4
The Infectious Diseases Society of America warns against polymyxin-rifampin combination therapy due to lack of proven benefit 4
The European Society of Clinical Microbiology and Infectious Diseases cautions against using carbapenems in monotherapy for severe infections in areas with high rates of resistance 1
The Intensive Care Medicine society emphasizes that dosing of colistin is complex and should be adjusted for renal function to minimize toxicity 5