What is the antimicrobial coverage of Amikacin (aminoglycoside antibiotic)?

From the Guidelines

Amikacin is recommended as a second-choice antibiotic for sepsis, to be used in combination with cloxacillin, cefotaxime, and ceftriaxone, with a typical adult dosing of 15-20 mg/kg IV once daily, and therapeutic drug monitoring is essential to minimize toxicity 1.

Amikacin Coverage

Amikacin is an aminoglycoside antibiotic that provides excellent coverage against many gram-negative bacteria, including Pseudomonas aeruginosa, Acinetobacter species, and Enterobacteriaceae (including many extended-spectrum beta-lactamase producers).

• The typical adult dosing is 15-20 mg/kg IV once daily, with a usual maximum of 1500 mg per day.
• For serious infections, the higher end of the dosing range is preferred.
• Therapeutic drug monitoring is essential when using amikacin, with target peak levels of 20-35 mcg/mL and trough levels below 5-10 mcg/mL to minimize toxicity.
• Treatment duration typically ranges from 5-7 days for uncomplicated infections to 10-14 days for more severe infections.
• Amikacin has poor coverage against gram-positive organisms and anaerobes, so it's often combined with other antibiotics for broader coverage.
• The drug concentrates in the urine, making it effective for complicated urinary tract infections.

Important Considerations

• Major concerns with amikacin include nephrotoxicity and ototoxicity, so renal function should be monitored closely, and the drug should be used cautiously in patients with pre-existing kidney disease or hearing impairment.
• Dosing adjustments are necessary for patients with renal impairment, as recommended by the KDIGO practice guideline on acute kidney injury in the individual patient 1.
• Single daily dosing is suggested for patients with stable normal kidney function rather than the traditional multiple dosing regimen, based on modest benefit from controlled trials and meta-analyses 1.
• For patients with cystic fibrosis, aerosolized tobramycin delivers high local levels of the aminoglycoside, and this delivery system has been shown to be effective, although there are reports of nephrotoxicity 1.

From the FDA Drug Label

Amikacin has been shown to be active against the following bacteria, both in vitro and in clinical infections... Gram-Positive Bacteria Staphylococcus species Gram-Negative Bacteria Pseudomonas species Escherichia coli Proteus species (indole-positive and indole-negative) Klebsiella species Enterobacter species Serratia species Acinetobacter species

Amikacin coverage includes:

• Gram-positive bacteria: Staphylococcus species
• Gram-negative bacteria:
  • Pseudomonas species
  • Escherichia coli
  • Proteus species (indole-positive and indole-negative)
  • Klebsiella species
  • Enterobacter species
  • Serratia species
  • Acinetobacter species 2

From the Research

Amikacin Coverage

• Amikacin is effective against most gram-negative bacteria, including gentamicin- and tobramycin-resistant strains 3.
• It is the aminoglycoside of choice for the treatment of known or suspected serious gram-negative infections caused by organisms resistant to gentamicin or tobramycin 3, 4.
• Amikacin has been shown to be effective in the treatment of serious gram-negative bacillary infections, including those caused by Pseudomonas aeruginosa 5, 6.
• The efficacy of amikacin is well documented, with high response rates reported in combination with beta-lactam antibiotics in immunocompromised or granulocytopenic patients 3.
• Amikacin achieves high and predictable serum concentrations and has a favorable therapeutic index, with a potential for nephrotoxicity and ototoxicity similar to that of gentamicin or tobramycin 3.

Spectrum of Activity

• Amikacin is active against a broad spectrum of gram-negative bacilli, including:
  • Pseudomonas aeruginosa 5, 3, 4
  • Gentamicin-resistant strains 3, 6, 4
  • Tobramycin-resistant strains 3, 4
• Amikacin is also effective against gram-negative bacteria that are resistant to other aminoglycosides 3, 4.

Clinical Use

• Amikacin can be used as part of an empiric antibiotic regimen for the therapy of suspected sepsis in febrile, leukopenic immunocompromised hosts 3.
• It is often used in combination with other antibiotics, such as beta-lactam antibiotics, to treat serious gram-negative infections 3, 6.
• Amikacin has been shown to be effective in the treatment of various types of infections, including:
  • Urinary tract infections 5
  • Bacteremia 5, 6
  • Pneumonia 7
  • Soft tissue infections 5