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(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


Increases cell membrane permeability in susceptible fungi


Ophthalmic: Systemic, <2%; Gastrointestinal: Poor


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

Use: Labeled Indications

Treatment of blepharitis, conjunctivitis, and keratitis caused by susceptible fungi (Aspergillus, Candida, Cephalosporium, Fusarium, and Penicillium)


Hypersensitivity to natamycin or any component of the formulation


Adults: Ophthalmic:

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

Fungal blepharitis or conjunctivitis: Instill 1 drop in conjunctival sac every 4-6 hours

Dosage adjustment in renal impairment: No dosage adjustment provided in manufacturer’s labeling. However, dosage adjustment unlikely due to low systemic absorption.

Dosage adjustment in hepatic impairment: No dosage adjustment provided in manufacturer’s labeling. However, dosage adjustment unlikely due to low systemic absorption.


Ophthalmic: Shake well before using, do not touch dropper to eye.


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

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: Contact lens should not be worn if signs/symptoms of fungal blepharitis, conjunctivitis, and/or keratitis are present. Contains benzalkonium chloride which may be absorbed by contact lenses; remove contact lens prior to administration and wait 15 minutes before reinserting.

Other warnings/precautions:

• Appropriate use: For topical eye use only. Failure to improve (keratitis) after 7-10 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 Risk Factor


Pregnancy Considerations

Animal reproduction studies have not been conducted.

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?)

• Have patient report immediately to prescriber vision changes, ophthalmalgia, 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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