IDOXURIDINE (IDU)

IDOXURIDINE (IDU)
(eye-dox-yoor'i-deen)
Dendrid, Herplex Liquifilm
Classifications: antiviral;
Therapeutic: antiviral
Prototype: Acyclovir
Pregnancy Category: C

Availability

0.1% ophthalmic solution

Action

Topical antiviral agent. Pyrimidine nucleoside structurally related to thymidine, a nucleic acid essential for synthesis of viral DNA. Antiviral activity is primarily due to inhibition of viral replication.

Therapeutic Effect

Inhibits growth of herpes simplex types I and II, varicella-zoster, vaccinia, cytomegalovirus, and small animal viruses containing DNA.

Uses

Herpes simplex keratitis as single agent or conjunctively with a corticosteroid.

Unlabeled Uses

Cutaneous herpes simplex.

Contraindications

Hypersensitivity to idoxuridine, iodine or iodine-containing preparations, or any components in the formulation, pregnancy (category C), lactation.

Cautious Use

Corticosteroid therapy.

Route & Dosage

Herpes Simplex Keratitis
Adult/Child: Topical 1 drop in conjunctival sac hourly during the day and q2h at night until improvement occurs, then decrease to q2h during the day and q4h at night

Administration

Topical

Prevent the possibility of systemic absorption by applying light finger pressure to head of lacrimal duct for 1 min when eyedrop is instilled.
Follow manufacturer's directions regarding storage. Decomposed idoxuridine not only has reduced antiviral activity but also may be toxic.
Store ophthalmic solution refrigerated at 2°–8° C (36°–46° F) in a tight, light-resistant container unless otherwise directed.

Adverse Effects (≥1%)

Body as a Whole: Sensitization, systemic absorption (stomatitis, anorexia, nausea, vomiting, alopecia, leukopenia, thrombocytopenia, iodism, hepatotoxicity). Special Senses: Local irritation, pain, burning, lacrimation, pruritus, inflammation, or edema of eyes, lids, and surrounding face; follicular conjunctivitis, photophobia; corneal ulceration and swelling; delayed healing, small defects in corneal epithelium (local overdosage).

Interactions

Drug: Boric acid-containing solutions may cause precipitation.

Pharmacokinetics

Absorption: Poorly absorbed from eye tissues. Distribution: Crosses placenta. Metabolism: In liver.

Nursing Implications

Assessment & Drug Effects

Monitor for therapeutic effectiveness. Epithelial infections usually improve within 7–8 d. If patient continues to improve, therapy is generally continued ≤21 d.
Supervise patients closely by ophthalmologist.

Patient & Family Education

Learn proper technique for eye drop instillation.
Do not exceed the recommended frequency and duration of therapy.
Wear sunglasses if photosensitivity is troublesome.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

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