From the Guidelines
The recommended treatment for Acinetobacter infections, particularly for carbapenem-resistant Acinetobacter baumannii (CRAB), involves the use of colistin, with a loading dose of 5 mg CBA/kg IV, followed by 2.5 mg CBA IV every 12 hours, often in combination with other agents such as imipenem/cilastatin or meropenem, as outlined in the most recent guidelines 1.
Key Considerations
- The choice of antibiotic treatment should be guided by susceptibility testing, as Acinetobacter species have developed significant resistance to many antibiotics.
- Combination therapy is often preferred over monotherapy due to increasing resistance patterns.
- Treatment duration generally ranges from 7-14 days, extending longer for complicated infections.
- Source control through drainage of abscesses or removal of infected devices is equally important for successful treatment.
Treatment Options
- For pneumonia caused by CRAB, the recommended treatment includes colistin, with or without imipenem/cilastatin or meropenem, and adjunctive colistin inhalation may be considered 1.
- For bloodstream infections, colistin, with or without imipenem/cilastatin or meropenem, is recommended, with treatment duration of 10-14 days 1.
- Sulbactam may be an option for patients with CRAB susceptible to sulbactam, particularly for hospital-acquired pneumonia (HAP) or ventilator-associated pneumonia (VAP) 1.
Important Notes
- Tigecycline may be used in combination with other antibiotics for the treatment of CRAB infections, but its use as monotherapy is not recommended due to concerns about efficacy and resistance development 1.
- Polymyxin B or high-dose tigecycline can be considered for patients with CRAB resistant to sulbactam, but the evidence for these options is limited 1.
From the FDA Drug Label
Amikacin sulfate injection, USP is indicated in the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Pseudomonas species, Escherichia coli, species of indole-positive and indole-negative Proteus, Providencia species, Klebsiella species, Enterobacter species, Serratia species, and Acinetobacter species To reduce the development of drug-resistant bacteria and maintain the effectiveness of amikacin and other antibacterial drugs, amikacin should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.
The recommended treatment for Acinetobacter infections is Amikacin.
- Key points:
- Amikacin is indicated for the short-term treatment of serious infections due to susceptible strains of Gram-negative bacteria, including Acinetobacter species.
- It is essential to use amikacin only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria to reduce the development of drug-resistant bacteria 2. However, Tigecycline may also be considered, but there have been reports of the development of tigecycline resistance in Acinetobacter infections, which appears to be attributable to an MDR efflux pump mechanism 3.
From the Research
Treatment Options for Acinetobacter Infections
The recommended treatment for Acinetobacter infections is a complex issue due to the high resistance of these bacteria to standard antibiotics.
- The choice of antibiotic should be guided by antibiograms that describe resistance mechanisms and the minimum inhibitory concentration (MIC) of the bacteria to different antibiotics 4.
- Combination therapy is often advised, but no specific combination has been shown to be superior to others 4.
- Some studies have investigated the use of colistin, tigecycline, and other antibiotics in combination with meropenem or other agents against extensively drug-resistant Acinetobacter baumannii (XDR-AB) 5, 6.
Antibiotic Combinations
- Colistin has been shown to be effective against XDR-AB, and its combination with rifampin or fusidic acid has been found to be synergistic in some studies 6.
- The combination of tigecycline, colistin, and meropenem has also been used to treat multidrug-resistant Acinetobacter baumannii bacteremia in some cases 7.
- However, the choice of antibiotic combination should be individualized based on the specific susceptibility pattern of the bacteria and the clinical parameters of the patient 4, 8.
Clinical Considerations
- Early identification and appropriate treatment of Acinetobacter infections are crucial to improve outcomes and reduce mortality 8.
- The use of empiric broad-spectrum antibiotics may be necessary in patients at risk for infections caused by multidrug-resistant pathogens, but this should be done judiciously to minimize the risk of further resistance development 8.
- Clinical parameters and biomarkers such as procalcitonin can be used to guide the treatment of Acinetobacter infections and monitor the response to therapy 4.