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Medically reviewed by Last updated on Jul 14, 2020.


(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

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:

• Change in taste

• Eye irritation

• Eye pain

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 or eyelid swelling

• Dizziness

• Passing out

• Fast heartbeat

• Abnormal heartbeat

• Sweating a lot

• Stevens-Johnson syndrome/toxic epidermal necrolysis like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in mouth, throat, nose, or eyes

• 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.