gentamicin sulfate at a glance
Medicine class
Aminoglycoside antibiotic
Main role
Serious susceptible bacterial infections; selected superficial eye and ear infections
Systemic administration
Given by a healthcare professional into a vein, by infusion or, for suitable formulations, into a muscle
Important monitoring
Blood concentrations, kidney function and signs of hearing or balance damage
What is gentamicin sulfate used for?
Licensed uses vary by formulation and product. Selected UK products cover:
Serious susceptible infections, including complicated urinary, hospital-acquired respiratory, intra-abdominal, bloodstream, burn, skin, soft-tissue and surgical infections.
Bronchopulmonary infection associated with cystic fibrosis and bacterial endocarditis.
Superficial susceptible bacterial infections of the eye or ear.
Prevention of infection following eye or ear trauma.
How does gentamicin sulfate work?
Gentamicin enters susceptible bacteria and binds irreversibly to the 30S ribosomal subunit. This disrupts bacterial protein production and usually kills the organism; it does not treat viral or fungal infections.
gentamicin sulfate preparations and strengths
Solution for infusion
Route: Intravenous
Strengths: 1 mg/mL, 3 mg/mL
Ear drops
Route: Otic
Strengths: 0.3%, 0.3% w/v
How to take gentamicin sulfate
Systemic gentamicin is prepared and administered by trained healthcare staff. Eye or ear drops should be used only in the site prescribed, without touching the dropper tip.
Remove contact lenses while an eye infection is being treated. Benzalkonium-containing drops can discolour soft lenses; wait before reinserting them as directed in the leaflet.
Do not use gentamicin ear drops if the eardrum is known or suspected to be perforated.
Eye drops can temporarily blur vision; do not drive or operate machinery until vision is clear.
Systemic formulations should not be mixed with other medicines unless compatibility has been confirmed.
gentamicin sulfate side effects
Common or expected effects
- Temporary blurred vision, burning, stinging, itching or irritation with eye or ear drops
- Nausea, vomiting or mouth soreness with systemic treatment
- Injection-site discomfort or local sensitivity
Get urgent medical advice
- Kidney injury, sometimes noticed as reduced urine output
- Inner-ear damage causing tinnitus, hearing loss, vertigo or impaired balance; hearing loss can be irreversible
- Severe allergic reaction
- Neuromuscular blockade, weakness or breathing impairment
- Severe skin reactions with blistering or peeling
- Severe or bloody diarrhoea, particularly when gentamicin is combined with other antibiotics
gentamicin sulfate in pregnancy
Available evidence does not show an increased risk of major birth defects after early aminoglycoside exposure, but pregnancy data remain limited. Systemic gentamicin crosses the placenta and is generally reserved for serious infections when a specialist considers it essential and suitable alternatives are unavailable. Eye and ear preparations have much lower systemic exposure, but should still be reviewed by the prescriber.
gentamicin sulfate while breastfeeding
Gentamicin can pass into breast milk, but absorption by a healthy infant's gut is expected to be low. Product-specific assessment is important, particularly if the mother has impaired kidney function or the infant has significant gastrointestinal inflammation. Discuss systemic or topical treatment with the prescriber responsible for the parent and baby.
gentamicin sulfate interactions
Check all prescribed, over-the-counter and hospital medicines because some combinations increase toxicity or neuromuscular effects.
Other aminoglycosides, vancomycin, amphotericin B, ciclosporin, cisplatin or polymyxins
Combining nephrotoxic medicines can increase kidney injury; avoidance or closer renal monitoring may be required.
Loop diuretics such as furosemide or ethacrynic acid
May increase the risk of hearing and balance toxicity.
Common questions about gentamicin sulfate
Answers are fully visible for fast scanning and source review.
Why are blood tests needed with gentamicin sulfate?
They check kidney function and measure gentamicin concentrations, helping clinicians limit toxicity while maintaining appropriate exposure.
Can gentamicin sulfate damage hearing?
Yes. It can damage the inner ear, causing tinnitus, hearing loss, dizziness or balance problems; hearing loss may be permanent.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.