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])
Pharmacology
Mechanism of Action
Interferes with bacterial protein synthesis by binding to 30S ribosomal subunit resulting in a defective bacterial cell membrane
Pharmacokinetics/Pharmacodynamics
Absorption
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, Enterobacter aerogenes, Escherichia coli, Haemophilus influenza, Klebsiella pneumonia, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Serratia marcescens.
Contraindications
Hypersensitivity to gentamicin or any component of the formulation
Dosage and Administration
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: Ophthalmic:
Ointment: Instill 1/2 inch (1.25 cm) to affected eye(s) 2 to 3 times/day
Solution: Instill 1 to 2 drops into affected eye(s) every 4 hours; up to 2 drops every hour for severe infections
Administration
For topical ophthalmic use only; not for injection into the eye. Avoid contaminating tip of the solution container or ointment tube.
Storage
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
>1%: Ophthalmic: Burning sensation of eyes, eye irritation
<1%, postmarketing, and/or case reports: Corneal ulcer, hallucination, hypersensitivity reaction, purpura, thrombocytopenia
Warnings/Precautions
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
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.
Frequently reported side effects of this drug
- Burning
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Vision changes
- Eye pain
- Severe eye irritation
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of 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 brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
