Skip to main content

Gentamicin (Ophthalmic)

Medically reviewed by Last updated on Jul 11, 2020.


(jen ta MYE sin)

Index Terms

  • Gentamicin Sulfate

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Ointment, Ophthalmic:

Gentak: 0.3% (3.5 g) [contains methylparaben, propylparaben]

Generic: 0.3% (3.5 g [DSC])

Solution, Ophthalmic:

Generic: 0.3% (5 mL, 15 mL [DSC])

Brand Names: U.S.

  • Gentak

Pharmacologic Category

  • Antibiotic, Aminoglycoside
  • Antibiotic, Ophthalmic


Interferes with bacterial protein synthesis by binding to 30S ribosomal subunit resulting in a defective bacterial cell membrane


Ophthalmic drops: Systemic absorption: Undetected (<0.5 mcg/mL)

Use: Labeled Indications

Ophthalmic infections: Topical treatment of ocular bacterial infections, including conjunctivitis, keratitis, keratoconjunctivitis, corneal ulcers, blepharitis, blepharoconjunctivitis, acute meibomianitis, and dacryocystitis caused by Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Klebsiella aerogenes (formerly Enterobacter aerogenes), Escherichia coli, Haemophilus influenza, Klebsiella pneumonia, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Serratia marcescens.


Hypersensitivity to gentamicin or any component of the formulation

Dosing: Adult

Ophthalmic infections: Ophthalmic:

Ointment: Instill 1/2" (1.25 cm) 2 to 3 times daily

Solution: Instill 1 to 2 drops every 4 hours, up to 2 drops every hour for severe infections

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Ophthalmic infections: Infants, Children, and Adolescents: Ophthalmic:

Ointment: Instill 1/2 inch (1.25 cm) to affected eye(s) 2 to 3 times daily.

Solution: Instill 1 to 2 drops into affected eye(s) every 4 hours; up to 2 drops every hour for severe infections.


For topical ophthalmic use only; not for injection into the eye. Avoid contaminating tip of the solution container or ointment tube.


Store at controlled room temperature of 20°C to 25°C (68°F to 77°F).

Drug Interactions

There are no known significant interactions.

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.

>1%: Ophthalmic: Burning sensation of eyes, eye irritation

<1%, postmarketing, and/or case reports: Corneal ulcer, hallucination, hypersensitivity reaction, purpura, thrombocytopenia


Concerns related to adverse effects:

• Corneal healing: May delay corneal healing.

• Sensitization: Topical use has been associated with local sensitization (redness, irritation); discontinue if sensitization is noted.

• Superinfection: Prolonged use may result in fungal or bacterial superinfection; if purulent discharge, inflammation, or pain are increased, therapy should be re-evaluated.

Other warnings/precautions:

• Appropriate use: Not for injection into the eye.

• Long-term use: Not intended for long-term therapy.

Pregnancy Risk Factor C Pregnancy Considerations

Adverse events were observed following systemic administration of gentamicin in animal reproduction studies. The amount of gentamicin available systemically following application of the ophthalmic drops is below the limit of detection (<0.5 mcg/mL) (Trope 1979). In general, if ophthalmic agents are needed in pregnant women, the minimum effective dose should be used in combination with punctal occlusion to decrease systemic absorption (Samples 1988).

Patient Education

What is this drug used for?

• It is used to treat eye infections.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Burning

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Vision changes

• Eye pain

• Severe eye irritation

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.