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Medically reviewed by Last updated on Jun 4, 2020.


(na ta MYE sin)

Index Terms

  • Pimaricin

Dosage Forms

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

Suspension, Ophthalmic:

Natacyn: 5% (15 mL)

Brand Names: U.S.

  • Natacyn

Pharmacologic Category

  • Antifungal Agent, Ophthalmic


Binds to sterol in fungal cell membrane and changes the cell wall permeability allowing for a reduction of cellular contents


Ophthalmic: Systemic, not expected; Gastrointestinal: Poor


Adheres to cornea, retained in conjunctival fornices; does not produce effective intraocular fluid concentrations

Use: Labeled Indications

Ocular fungal infections: Treatment of fungal blepharitis, conjunctivitis, and keratitis caused by susceptible organisms, including Fusarium solani keratitis.


Hypersensitivity to natamycin or any component of the formulation

Dosing: Adult

Fungal keratitis: Ophthalmic: Instill 1 drop in conjunctival sac every 1 to 2 hours, after 3 to 4 days reduce to one drop 6 to 8 times daily; usual course of therapy is 2 to 3 weeks or until resolution of active fungal keratitis (may be useful to gradually reduce dosage at 4- to 7-day intervals to assure elimination of organism)

Fungal blepharitis or conjunctivitis: Ophthalmic: Instill 1 drop in conjunctival sac 4 to 6 times daily

Dosing: Geriatric

Refer to adult dosing.


Ophthalmic: For topical ophthalmic use only. Shake well before using. Wash hands before and after use. Do not touch tip of applicator to eye or other surfaces.


Store at 2°C to 24°C (36°F to 75°F); do not freeze. Protect from excessive heat and light.

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.

Postmarketing and/or case reports: Allergic reaction, chest pain, corneal opacity, dyspnea, eye discomfort, edema, hyperemia, irritation and/or pain, foreign body sensation, parasthesia, tearing, vision changes


Disease-related concerns:

• Epithelial ulceration: Suspension may adhere to epithelial ulcers; retention of the suspension in the fornices occurs regularly.

Special populations:

• Contact lens wearers: Contains benzalkonium chloride, which may be absorbed by soft contact lenses; remove lenses prior to administration. Contact lenses should not be worn during treatment of ophthalmologic infections (including fungal blepharitis, conjunctivitis, and keratitis).

Other warnings/precautions:

• Appropriate use: For topical ophthalmic use only. Failure to improve (keratitis) after 7 to 10 days of administration suggests infection caused by a microorganism not susceptible to natamycin; efficacy as a single agent in fungal endophthalmitis has not been established.

Pregnancy Considerations

Animal reproduction studies have not been conducted.

Patient Education

What is this drug used for?

• It is used to treat eye infections.

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.