From the Guidelines
Amikacin can be considered for the treatment of Pseudomonas urinary tract infections, but it is not effective against Enterococcus and should be used with caution due to its potential nephrotoxicity and ototoxicity. For Pseudomonas UTIs, amikacin is often used at doses of 15 mg/kg IV once daily, as recommended by the Journal of Microbiology, Immunology and Infection 1. The duration of treatment typically ranges from 5 to 14 days, depending on the severity of the infection. However, amikacin is not considered first-line therapy for Pseudomonas UTIs due to its potential side effects. For Enterococcus UTIs, amikacin is ineffective because enterococci have intrinsic resistance to aminoglycosides when used alone, and are typically treated with ampicillin (if susceptible) or vancomycin (for resistant strains) 1. If treating a UTI with both organisms present, combination therapy would be needed, typically a beta-lactam or vancomycin for Enterococcus plus either a fluoroquinolone, cephalosporin, or carbapenem for Pseudomonas. Some key points to consider when using amikacin include:
- Monitoring renal function is essential, with dose adjustments needed for patients with impaired kidney function
- Aminoglycoside monotherapy is only indicated for urinary tract infections, as stated in the Journal of Microbiology, Immunology and Infection 1
- Combination therapy may be necessary for severe or complicated infections, as suggested by the European Society of Clinical Microbiology and Infectious Diseases guidelines 1
From the FDA Drug Label
INDICATIONS AND USAGE: 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
- Pseudomonas: Amikacin is indicated for the treatment of serious infections due to susceptible strains of Pseudomonas species.
- Enterococcus: The drug label does not mention Enterococcus as a susceptible strain, Enterococcus is a Gram-positive bacterium, and the label specifically states that amikacin is indicated for Gram-negative bacteria. Amikacin may be appropriate for Pseudomonas UTI, but it is not appropriate for Enterococcus UTI 2
From the Research
Amikacin for Enterococcus and Pseudomonas UTI
- The effectiveness of amikacin against Enterococcus and Pseudomonas UTI is a complex issue, with various studies providing insights into its potential use.
- For Enterococcus, a study from 3 highlights the challenges in treating multidrug-resistant enterococcal infections, but does not specifically mention amikacin as a recommended treatment option.
- However, a study from 4 found that amikacin in combination with beta-lactam antibiotics, such as piperacillin, ceftazidime, and ceftriaxone, exhibited a synergistic post-antibiotic effect against Enterococcus faecalis.
- Regarding Pseudomonas, a study from 5 discusses the limited choices of antibiotics and emerging resistance, but does not mention amikacin as a primary treatment option.
- Nevertheless, a study from 6 demonstrated that amikacin in combination with beta-lactam antibiotics, such as ceftazidime, ceftriaxone, and piperacillin, showed a synergic post-antibiotic effect against Pseudomonas aeruginosa.
- Another study from 7 found that amikacin was effective in treating lower urinary tract infections caused by extended-spectrum beta-lactamase-producing Escherichia coli or Klebsiella pneumoniae, with a clinical success rate of 97.2% and bacteriological success rates of 91.7% to 97.1%.
Considerations for Amikacin Use
- The use of amikacin against Enterococcus and Pseudomonas UTI should be considered in the context of the specific bacterial strains and their resistance patterns, as well as the patient's individual circumstances, as noted in 3 and 5.
- Combination therapy with beta-lactam antibiotics may enhance the effectiveness of amikacin, as seen in studies 6 and 4.
- However, the potential for nephrotoxicity, as reported in 7, should also be taken into account when considering amikacin treatment.