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Gentamicin (Ophthalmic)

Pronunciation

Pronunciation

(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:

Garamycin: 0.3% (3.5 g [DSC])

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

Generic: 0.3% (3.5 g)

Solution, Ophthalmic:

Garamycin: 0.3% (5 mL [DSC]) [contains benzalkonium chloride]

Generic: 0.3% (5 mL, 15 mL)

Brand Names: U.S.

  • Garamycin [DSC]
  • Gentak

Pharmacologic Category

  • Antibiotic, Aminoglycoside
  • Antibiotic, Ophthalmic

Pharmacology

Interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits resulting in a defective bacterial cell membrane

Absorption

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

Use: Labeled Indications

Treatment of ophthalmic infections caused by susceptible bacteria

Contraindications

Hypersensitivity to gentamicin, or other components of the formulation

Dosing: Adult

Ophthalmic infections: Ophthalmic:

Ointment: Instill 1/2” (1.25 cm) 2-3 times/day to every 3-4 hours

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

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Ophthalmic infections: Children: Refer to adult dosing.

Administration

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% (Limited to important or life-threatening): 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 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 punctual occlusion to decrease systemic absorption (Samples 1988).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience burning or stinging. Have patient report immediately to prescriber vision changes, eye pain, or severe eye irritation (HCAHPS).

• Educate patient about signs of a significant reaction (eg, 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. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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