NATAMYCIN (na-ta-mye'sin)
Natacyn Classifications: antifungal agent; Therapeutic: antifungal Prototype: Amphotericin B Pregnancy Category: C
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Availability
5% suspension
Action
Mechanism of action simulates that of amphotericin B and nystatin by binding to sterols in the fungal cell membrane resulting
in cell death of fungi.
Therapeutic Effect
Effective against many yeasts and filamentous fungi including Candida, Aspergillus, Cephalosporium, Fusarium, and Penicillium. Limited activity in vivo against Trichomonas vaginalis.
Uses
Blepharitis, conjunctivitis, and keratitis caused by susceptible fungi. Drug of choice for Fusarium solani keratitis.
Unlabeled Uses
Oral, cutaneous, and vaginal candidiasis; intranasal treatment of pulmonary aspergillosis.
Contraindications
Concomitant administration of a corticosteroid.
Cautious Use
Pregnancy (category C) or lactation. Safety and efficacy in children are not established.
Route & Dosage
Fungal Keratitis Adult: Ophthalmic 1 drop in conjunctival sac of infected eye q12h for 34 d, then decrease to 1 drop q68h, then gradually
decrease to 1 drop q47d
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Administration
Instillation
- Wash hands thoroughly before and after treatment. Infection is easily transferred from infected to noninfected eye and to
other individuals.
- Shake well before using.
- Store at 2°24° C (36°75° F).
Adverse Effects (≥1%)
Special Senses: Blurred vision, photophobia, eye pain. Uneven adherence of suspension to epithelial ulcerations or in fornices.
Interactions
Drug: No clinically significant interactions established.
Pharmacokinetics
Absorption: Drug adheres to ulcerated surface of the cornea and is retained in conjunctival fornices. Does not appear to be systemically
absorbed.
Nursing Implications
Assessment & Drug Effects
- Inspect eye for response and tolerance at least twice weekly.
- Note: Lack of improvement in keratitis within 710 d suggests that causative organisms may not be susceptible to natamycin.
Reevaluation is indicated and possibly a change in therapy.
Patient & Family Education
- Learn appropriate technique for application of eye drops.
- Expect temporary light sensitivity. Be prepared to wear sunglasses outdoors after drug administration and perhaps for a
few hours indoors.
- Return to ophthalmologist for reevaluation of eye problem if you experience symptoms of conjunctivitis: pain, discharge,
itching, scratching "foreign body sensation," changes in vision.
- Do not share facecloths and hand towels; this will help prevent transmission of the fungal infection.