Overview
Naphazoline is a topical ophthalmic vasoconstrictor used for temporary relief of ocular redness and irritation. It works by constricting conjunctival blood vessels to reduce redness and soothe minor eye discomfort. This medication is available over-the-counter for short-term symptomatic relief.
Mechanism of Action
Naphazoline is a direct-acting sympathomimetic amine that stimulates alpha-adrenergic receptors in the conjunctival blood vessels, causing vasoconstriction. This reduces blood flow to the ocular surface, decreasing redness and providing temporary relief from minor eye irritation.
Indications
- Temporary relief of burning and irritation due to eye dryness
- Relief of redness due to minor eye irritations
Common Doses
- 0.012% solution (typical OTC strength)
- 0.1% solution (prescription strength in some formulations)
Dosage
Instill 1-2 drops in the affected eye(s) up to 4 times daily. Tightly screw cap after each use to maintain sterility.
Contraindications
- Hypersensitivity to naphazoline or any component of the formulation
- Narrow-angle glaucoma (requires medical consultation before use)
Side Effects
- Temporary stinging or burning upon instillation
- Pupillary dilation (mydriasis)
- Blurred vision
- Rebound hyperemia with prolonged use
- Headache
- Increased intraocular pressure in susceptible individuals
Interactions
- Potential additive effects with other sympathomimetic agents
- May interfere with monoamine oxidase inhibitors (MAOIs)
- Concurrent use with other ophthalmic medications may alter absorption
Counseling Points
- Use only as directed - do not exceed 4 times daily
- Wait at least 5 minutes before reinserting contact lenses
- Do not use if solution becomes discolored or cloudy
- Symptoms should improve within minutes; discontinue if no improvement after 72 hours
- Store at room temperature and protect from light
- Keep out of reach of children