What is gentamicin, and how does it work (mechanism of action)?

Gentamicin is a broad spectrum aminoglycoside antibiotic that is most effective against aerobic gram-negative rods. Gentamicin is also used in combination with other antibiotics to treat infections caused by gram positive organisms such as Staphylococcus aureus and certain species of streptococci. Additionally, gentamicin is used in combination with a penicillin antibiotic to treat endocarditis (infection of the heart). Gentamicin kills bacteria (bactericidal) by inhibiting the synthesis of bacterial proteins. Gentamicin irreversibly binds to the 30S ribosomal subunits. This binding interferes with the formation of messenger RNA (mRNA) and the subsequent formation of nonfunctional proteins and the eventual death of susceptible bacteria. Gentamicin was approved by the US Food and Drug Administration (FDA) in 1966.

What brand names are available for gentamicin?

Gentamicin Injection, Garamycin

Is gentamicin available as a generic drug?


Do I need a prescription for gentamicin?


What are the side effects of gentamicin?

Side effects associated with gentamicin use are:

What is the dosage for gentamicin?

The dose of gentamicin is usually based on body weight. Total daily dose and duration of treatment depend on the condition or infection being treated. Dose adjustment is necessary for patients who have impaired kidney function. Doses are adjusted to target peak and trough levels.

  • Usual dosage ranges for IM or IV:
  • Conventional dosing: Administer 1 to 2.5 mg/kg/dose every 8-12 hours.
  • Once daily dosing: Administer 4 to 7 mg/kg/day.

Which drugs or supplements interact with gentamicin?

Gentamicin may decrease the effectiveness of the BCG and typhoid vaccine.

Cephalosporins, amphotericin B (Amphocin), cisplatin (Platinol), colistimethate, cyclosporine (Sandimmune), loop diuretics, mannitol (Osmitrol), and vancomycin (Vancocin) may increase the risk of experiencing kidney related side effects of gentamicin.

Nonsteroidal anti-inflammatory agents (NSAIDs) may decrease the kidney excretion or clearance of gentamicin. Examples of NSAIDs are:

Neuromuscular blocking agents may increase the risk of experiencing breathing problems by depressing the activity of respiratory muscles when given with gentamicin.

Loop diuretics such as furosemide (Lasix), bumetanide (Bumex), and torsemide (Demadex) may increase the ototoxicity (hearing impairment) associated with gentamicin treatment.

Is gentamicin safe to take if I’m pregnant or breastfeeding?

Gentamicin is excreted into human milk. Due to the lack of safety data, gentamicin should be used cautiously in nursing mothers. The benefits of breastfeeding, potential risk of infant drug exposure, and risk of inadequately or untreated infection should all be considered when deciding if gentamicin should be used in females who are breastfeeding.

What else should I know about gentamicin?

What preparations of gentamicin are available?

Gentamicin sulfate solution for injection: 10, 40 mg/ml

How should I keep gentamicin stored?

Gentamicin is usually given as an injection at the hospital, clinic, or doctor’s office. Patient’s using gentamicin solution at home should check with their healthcare provider on details regarding the proper storage of their medication.

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Medically Reviewed on 3/18/2019


Medically reviewed by John P. Cunha, DO, FACOEP; Board Certified Emergency Medicine


FDA Prescribing Information.