NAFALANT EYE DROPS

Indications

• Nasal congestion
• Allergic rhinitis
• Ocular redness and irritation
• Sinusitis

Dosage

Children: Refer to the BNF for Children for specific dosing information.

Adults: Refer to the BNF for specific dosing information.

Mechanism of action

Naphazoline is a vasoconstrictor that functions by stimulating alpha adrenergic receptors in arterioles, leading to decreased congestion at the site of administration. It causes the release of norepinephrine in sympathetic nerves, which binds to alpha adrenergic receptors and causes vasoconstriction. Additionally, naphazoline is a mild beta adrenergic receptor agonist, potentially resulting in rebound vasodilation after the alpha adrenergic stimulation has ceased. Its norepinephrine release triggers a negative feedback loop that reduces norepinephrine production, which can contribute to rhinitis medicamentosa upon cessation after prolonged use.

Pharmacodynamics

Naphazoline is a sympathomimetic alpha adrenergic agonist that acts to vasoconstrict nasal or ocular arterioles, resulting in reduced congestion at the site of administration. This property makes it effective in managing symptoms of nasal congestion and eye irritation.

Pharmacokinetics

The pharmacokinetics of naphazoline are characterized by its local action at the site of administration, with rapid onset of action. It undergoes systemic absorption; however, detailed pharmacokinetic parameters such as half-life, distribution volume, and elimination routes are not well documented in the provided sources.

Adverse effects

• Burning or stinging sensation in the nose or eyes
• Rebound congestion
• Increased blood pressure
• Tachycardia
• Headache
• Nausea

Precautions

• Use with caution in patients with cardiovascular disease
• Caution in patients with hypertension or hyperthyroidism
• Avoid prolonged use to prevent rhinitis medicamentosa

Pregnancy

Naphazoline should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Caution is advised when using naphazoline while breastfeeding.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Nasal spray
• Eye drops

Mechanism of action

Naphazoline is a vasoconstrictor that functions by stimulating alpha adrenergic receptors in arterioles leading to decreased congestion at the site of administration. Naphazoline causes the release of norepinephrine in sympathetic nerves. Norepinephrine binds to alpha adrenergic receptors and causes vasoconstriction. Naphazoline is also a mild beta adrenergic receptor agonist, which can cause rebound vasodilation after the alpha adrenergic stimulation has ended. Naphazoline's release of norepinephrine also triggers a negative feedback loop which decreases production of norepinephrine, which can lead to rhinitis medicamentosa after long term use when naphazoline is stopped.

Pharmacodynamics

Naphazoline is a sympathomimetic alpha adrenergic agonist that acts to vasoconstrict nasal or ocular arterioles, resulting in reduced congestion at the site of administration.