Iridina Due (Naphazoline Hydrochloride)

Naphazoline Hydrochloride is used as an ocular decongestant to address conditions characterized by conjunctival hyperemia.

• Ocular redness: provides rapid reduction of visible redness in the white of the eye.
• Conjunctival hyperemia: alleviates redness caused by minor irritation or allergic response.
• Post‑procedural eye redness: helps diminish transient redness after minor eye procedures.

• Naphazoline Hydrochloride acts as a selective alpha‑adrenergic receptor agonist on the smooth muscle of conjunctival blood vessels. Activation of α1‑adrenergic receptors induces vasoconstriction, decreasing blood flow to the ocular surface. The reduced perfusion limits extravasation of blood into the conjunctiva, thereby diminishing the appearance of redness while providing temporary relief without affecting intra‑ocular pressure.

Topical ocular administration of Naphazoline Hydrochloride may be associated with a range of local and systemic reactions.

Common Side Effects

• Burning sensation: mild stinging upon instillation.
• Stinging or itching: transient discomfort in the eye.
• Dryness: temporary reduction of tear film.
• Blurred vision: short‑lasting visual disturbance.
• Pupil dilation: mild mydriasis in sensitive individuals.

Serious or Rare Side Effects

• Elevated intra‑ocular pressure: possible increase in glaucoma patients.
• Allergic reaction: redness, swelling, or rash around the eye.
• Systemic hypertension: rare rise in blood pressure after excessive use.
• Corneal ulceration: severe ocular surface damage with prolonged misuse.

When using Iridina Due, several precautions should be observed to ensure safety and effectiveness.

• Contraindication: avoid use in patients with narrow‑angle glaucoma.
• Frequency: limit application to no more than one drop per eye every 4–6 hours, not exceeding four doses per day.
• Duration: do not use continuously for more than three consecutive days without medical advice.
• Contact lens wearers: remove lenses before instillation and wait several minutes before reinserting.
• Systemic conditions: use cautiously in individuals with hypertension or cardiovascular disease.
• Store at room temperature: keep in the original container, protect from moisture and light.

Naphazoline Hydrochloride can interact with other ophthalmic or systemic agents.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): may potentiate hypertensive response.
• Other ocular decongestants: combined use can cause excessive vasoconstriction and rebound redness.

Moderate Interactions (Monitor Closely)

• Antihypertensive medications: monitor blood pressure if systemic absorption occurs.
• Non‑steroidal anti‑inflammatory eye drops: may increase risk of ocular irritation.
• Beta‑blocker eye drops: observe for additive effects on intra‑ocular pressure.