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Medically reviewed by Last updated on Jul 15, 2019.


(gat i FLOKS a sin)

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Solution, Ophthalmic:

Zymaxid: 0.5% (2.5 mL) [contains benzalkonium chloride, edetate disodium]

Generic: 0.5% (2.5 mL)

Brand Names: U.S.

  • Zymaxid

Pharmacologic Category

  • Antibiotic, Fluoroquinolone
  • Antibiotic, Ophthalmic


Gatifloxacin is a DNA gyrase inhibitor, and also inhibits topoisomerase IV. DNA gyrase (topoisomerase II) is an essential bacterial enzyme that maintains the superhelical structure of DNA. DNA gyrase is required for DNA replication and transcription, DNA repair, recombination, and transposition; inhibition is bactericidal.


Ophthalmic: Not measurable (<5 ng/mL)

Use: Labeled Indications

Conjunctivitis: Treatment of bacterial conjunctivitis caused by Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mitis group, Streptococcus oralis, Streptococcus pneumoniae, and Haemophilus influenzae.

Off Label Uses

Bacterial keratitis

Data from a limited number of patients in two small randomized trials support the use of gatifloxacin in the treatment of bacterial keratitis [Parmar 2006], [Shah 2010]. Additional data may be necessary to further define the role of gatifloxacin for this condition.

Based on the American Academy of Ophthalmology Preferred Practice Pattern Guidelines for Bacterial Keratitis, gatifloxacin is an effective and recommended agent in the management of bacterial keratitis.


Hypersensitivity to gatifloxacin, other quinolones, or any component of the formulation

Dosing: Adult

Bacterial conjunctivitis: Ophthalmic:

Zymar [Canadian product]:

Days 1 and 2: Instill 1 drop into affected eye(s) every 2 hours while awake (maximum: 8 times/day).

Days 3 to 7: Instill 1 drop into affected eye(s) 4 times/day while awake.


Day 1: Instill 1 drop into affected eye(s) every 2 hours while awake (maximum: 8 times/day).

Days 2 to 7: Instill 1 drop into affected eye(s) 2 to 4 times/day while awake.

Bacterial keratitis (off-label use): Ophthalmic: Instill 1 drop into affected eye(s) every 1 hour around the clock until healing begins (usually 48 to 72 hours); dosing frequency is then gradually reduced until the ulcer is completely healed, at which point, treatment can be discontinued (Parmar 2006; Shah 2010). One suggested tapering regimen is as follows: Days 3 to 6: Instill 1 drop into affected eye(s) every 2 hours around the clock; Days 7 to 9: Instill 1 drop into affected eye(s) every 2 hours while awake; Day 9 and on: Instill 1 drop into affected eye(s) every 6 hours and continue at this frequency until complete healing of ulcer (Shah 2010). Note: For central or severe keratitis, a loading dose of instillation every 5 to 15 minutes for the first 30 to 60 minutes may be considered (AAO 2013).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Bacterial conjunctivitis: Ophthalmic: Children ≥1 year and Adolescents: Zymaxid: Day 1: Instill 1 drop into affected eye(s) every 2 hours while awake (maximum: 8 times/day). Days 2 to 7: Instill 1 drop into affected eye(s) 2 to 4 times/day while awake.


For topical ophthalmic use only; not for injection. Avoid touching tip of applicator to eye, fingers, or other surfaces.


Store between 15°C to 25°C (59°F to 77°F); protect from freezing.

Drug Interactions

There are no known significant interactions.

Adverse Reactions

1% to 10%:

Central nervous system: Headache

Endocrine & metabolic: Chemosis

Gastrointestinal: Dysgeusia

Ophthalmic: Conjunctival hemorrhage, conjunctival irritation, conjunctivitis (worsening), decreased visual acuity, dry eye syndrome, eye discharge, eye irritation, eye pain, eye redness, eyelid edema, increased lacrimation, keratitis, papillary conjunctivitis

<1%, postmarketing, and/or case reports: Anaphylaxis, angioedema (including facial edema, oral edema, pharyngeal edema), blepharitis, blurred vision, dyspnea, eye pruritus, hypersensitivity reaction (including allergic dermatitis, eye allergy), nausea, pruritus (including skin rash), Stevens-Johnson syndrome, swelling of eye (including corneal edema, conjunctival edema), urticaria


Concerns related to adverse effects:

• Hypersensitivity reactions: Hypersensitivity reactions, including anaphylactic reactions, angioedema (including pharyngeal, laryngeal, or facial edema), dyspnea, urticaria, and itching, have been reported (even following a single dose) with topical ophthalmic gatifloxacin. Rare cases of Stevens-Johnson syndrome were also reported. If an allergic reaction occurs, discontinue use.

• Superinfection: Prolonged use may result in fungal or bacterial superinfection. If superinfection is suspected, institute appropriate alternative therapy.

Special populations:

• Contact lens wearers: Contact lenses should not be worn during treatment of ophthalmic infections.

Dosage form specific issues:

• Appropriate use: For topical ophthalmic use only. Do not inject ophthalmic solution subconjunctivally or introduce directly into the anterior chamber of the eye (may cause corneal endothelial cell injury).

Pregnancy Considerations

Systemic concentrations of gatifloxacin following ophthalmic administration are below the limit of quantification. If ophthalmic agents are needed during pregnancy, the minimum effective dose should be used in combination with punctal occlusion for 3 to 5 minutes after application to decrease potential exposure to the fetus (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 change in taste. Have patient report immediately to prescriber vision changes, eye pain, severe eye irritation, signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes), or eye or eyelid edema (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 health care 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.

Further information

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