Naphazoline + Zinc Sulfate

Approved Indications:

• Ocular Irritation and Redness Relief:
• Temporary relief of eye redness and minor irritation caused by exposure to wind, dust, smoke, chlorinated water, or prolonged screen time.
• Allergic Conjunctivitis:
• Reduces ocular itching, redness, burning, and watery discharge due to allergies from pollen, pet dander, mold, or dust.
• Non-infectious Conjunctival Congestion:
• Used to alleviate conjunctival hyperemia due to fatigue, lack of sleep, or minor chemical exposure.

Clinically Accepted Off-Label Uses:

• Supportive Management in Mild Viral Conjunctivitis:
• Provides symptomatic relief from eye redness and irritation (as an adjunct to viral eye care).
• Post-operative Minor Eye Irritation:
• Occasionally used post-eye surgery to reduce surface discomfort (under specialist direction).

Note: Not intended to treat eye infections (bacterial, fungal, or viral), nor for long-term use.

Route of Administration: Ophthalmic (eye drops)

Adults and Children ≥6 years:

• Instill 1–2 drops into the affected eye(s) every 3–4 hours as needed.
• Maximum: 4 times daily.
• Duration: Do not use for more than 72 consecutive hours without medical supervision.

Children <6 years:

• Use only under medical supervision due to increased risk of systemic absorption and CNS depression.

Elderly:

• Use with caution; increased sensitivity to systemic vasoconstrictive effects is possible.

Renal and Hepatic Impairment:

• No dosage adjustment required for ophthalmic use.
• Caution advised in severe renal or hepatic disease due to possible systemic absorption.

Administration Instructions:

• Wash hands before use. Tilt head back, pull down the lower eyelid, and apply drops to the conjunctival sac.
• Avoid touching the dropper tip to any surface.
• Apply gentle pressure to the inner corner of the eye (nasolacrimal duct) for 1–2 minutes to minimize systemic absorption.
• Remove contact lenses before application; wait at least 15 minutes before reinsertion.

Naphazoline is a sympathomimetic amine that acts as a selective alpha-adrenergic agonist, primarily on alpha-1 receptors in the conjunctival arterioles. It induces vasoconstriction of dilated blood vessels in the eye, thereby reducing redness and swelling.
Zinc Sulfate works as a mild astringent and anti-irritant, stabilizing cell membranes of the conjunctiva and reducing ocular discomfort caused by allergens or irritants. Together, they provide quick and effective relief from redness, itching, and irritation of non-infectious origin.

• Absorption:
• Naphazoline may be minimally absorbed through the conjunctival mucosa and nasolacrimal drainage into systemic circulation.
• Zinc Sulfate has negligible systemic absorption when applied topically.
• Onset of Action:
• Typically within 5 minutes of instillation.
• Duration of Action:
• Usually 4 to 6 hours after a single application.
• Distribution & Protein Binding:
• Limited systemic distribution due to low absorption.
• Metabolism:
• Naphazoline is metabolized hepatically after systemic absorption.
• Excretion:
• Primarily via urine (minimal quantities).
• No active metabolites relevant to therapeutic effect.

• Pregnancy:
• FDA Pregnancy Category C (naphazoline):
  No adequate human studies. Use only if potential benefit justifies the potential risk to the fetus.
• Zinc sulfate is generally safe at trace levels.
• Lactation:
• It is unknown if naphazoline is excreted into human milk.
• Caution is advised when used in nursing mothers. Use only under physician guidance.

• Primary Class: Ocular Decongestant + Astringent
• Components:
• Naphazoline: Alpha-adrenergic vasoconstrictor
• Zinc Sulfate: Trace element with astringent and soothing properties

• Hypersensitivity to naphazoline, zinc sulfate, or formulation components
• Narrow-angle glaucoma
• Severe ocular pain, blurred vision, or photophobia (requires medical evaluation)
• Children under 6 years (unless specifically directed by a physician)
• Patients taking monoamine oxidase inhibitors (MAOIs) or within 14 days of stopping such therapy

• Rebound Congestion (Rebound Hyperemia):
• Prolonged use may lead to worsening redness due to vascular dependency.
• Systemic Vasoconstrictive Effects:
• Risk of hypertension, bradycardia, or CNS depression, especially in young children or elderly patients.
• Ocular Dryness or Irritation:
• May cause transient burning, dryness, or stinging.
• Contact Lens Users:
• Should remove lenses before use. Preservatives may discolor or damage soft contact lenses.
• Short-Term Use Only:
• Limit to 3 days of consecutive use to avoid complications.
• Use in Glaucoma:
• Contraindicated in angle-closure glaucoma due to risk of elevated intraocular pressure.

Common:

• Ocular burning or stinging upon instillation
• Temporary blurred vision
• Dry or irritated eyes
• Mild headache

Less Common but Serious:

• Rebound redness after prolonged use
• Palpitations, hypertension, bradycardia (especially in overdose or pediatric misuse)
• CNS depression (in infants or overuse): lethargy, hypotonia, hypothermia
• Allergic reactions: conjunctival swelling, eyelid edema, rash

• MAO Inhibitors (e.g., phenelzine, tranylcypromine):
• May cause severe hypertensive crisis when combined with naphazoline.
• Tricyclic Antidepressants (e.g., amitriptyline):
• May potentiate vasopressor response of naphazoline.
• Antihypertensives or Beta-blockers:
• Additive effects possible if systemic absorption occurs.
• CNS Depressants (e.g., sedatives, alcohol):
• May enhance sedative effect of systemic naphazoline (though rare with topical use).
• Enzyme Involvement:
• Naphazoline undergoes hepatic metabolism; not a significant CYP450 substrate.

• Usage Limitation:
• Eye care guidelines emphasize short-term use (≤72 hours) to prevent rebound congestion.
• Label Warnings Enhanced:
• Updated labels highlight caution in children, elderly, and patients with glaucoma.
• Global Regulatory Trends (FDA, EMA):
• Emphasize need for supervised use in pediatric groups and patients with comorbidities due to systemic absorption risks.

• Recommended Temperature: Store at 15°C to 30°C (59°F to 86°F)
• Humidity & Light: Protect from excessive heat and light
• Do Not Freeze
• Handling Precautions:
• Do not touch dropper tip to any surface to avoid contamination
• Discard solution if cloudy, discolored, or expired
• Use within 28 days of opening (check manufacturer's label for specific expiry after opening)