EMEDASTINE DIFUMARATE

EMEDASTINE DIFUMARATE

(em-e-das'teen di-foom'a-rate)

Emadine
Classifications: eye preparation; antihistamine, ocular; h₁-receptor antagonist;
Therapeutic:ocular antihistamine
Pregnancy Category: B

Availability

0.05% ophthalmic solution

Action

Emedastine is a selective antagonist at H₁-receptors. It blocks H₁-receptors and inhibits histamine-stimulated vascular permeability in the conjunctiva. As a result, emedastine relieves the ocular pruritus associated with allergic conjunctivitis.

Therapeutic Effect

Relieves ocular pruritus related to allergic response to histamine.

Uses

Temporary relief of seasonal allergic conjunctivitis.

Contraindications

Hypersensitivity to emedastine.

Cautious Use

Hypersensitivity to other antihistamines, soft contact lenses; pregnancy (category B), lactation. Safety and efficacy in children <3 y are not established.

Route & Dosage

Allergic Conjunctivitis
Adult: Ophthalmic 1 drop in affected eye q.i.d.

Administration

Instillation

Wash hands before and after use.
Shake well before using. Apply drops in the center of the lower conjunctional sac. Do not touch eyelids with dropper.
Gently close eyes for 1–2 min after installation of drops.
Wait 10 min after installation of drug before inserting soft lenses into eyes
Store in a tightly closed bottle. Protect the solution from light.
Do not use if discolored.

Adverse Effects (≥1%)

CNS: Headache. Special Senses: Ocular irritation, mild transient stinging and burning, conjunctival congestion, eyelid edema, eye pain, photophobia, abnormal lacrimation.

Interactions

Drug: No clinically significant interactions established.

Pharmacokinetics

Absorption: Minimal. Half-Life: 3–4 h.

Nursing Implications

Assessment & Drug Effects

Monitor for S&S of hypersensitivity to the drug (see Appendix F).
Evaluate safety of engaging in hazardous activities since drowsiness is a potential adverse effect.

Patient & Family Education

Learn potential adverse responses to emedastine.
Eye drops contain benzalkonium chloride, which may damage soft contact lenses. After instillation of drops, wait 10 min before inserting these contact lens into the eye.
Contact your physician if symptoms do not start to improve in 2 or 3 d.

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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