← Search & browse all drugs

phenylephrine

S01GA05

Forms & Strengths

Ophthalmic Solution: 2.5%
Ophthalmic Solution: 10%

Adult Dosing

Vasoconstriction and mydriasis: Instill 1 drop of 2.5% or 10% solution into the conjunctival sac.
Uveitis management: Instill 1 drop of 2.5% or 10% solution up to TID as needed.

Pediatric Dosing

Infants and Children: 2.5% ophthalmic solution only (10% is generally contraindicated due to systemic toxicity risks).
Mydriasis for examination: 1 drop of 2.5% solution prior to procedure.

Indications

Production of mydriasis for diagnostic ophthalmic procedures
Vasoconstriction and decongestion of conjunctival membranes
Management of posterior synechiae in uveitis

Mechanism of Action

Direct-acting alpha-1 adrenergic receptor agonist
Stimulation of dilator pupillae muscle contraction resulting in mydriasis
Constriction of conjunctival arterioles reducing vascular congestion

Contraindications

Angle-closure glaucoma
Hypersensitivity to phenylephrine or any component
10% concentration contraindicated in infants, the elderly, and patients with severe cardiovascular disease, aneurysm, or poorly controlled hypertension

Adverse Reactions

Transient stinging and burning upon instillation
Blurred vision
Increased intraocular pressure
Systemic cardiovascular effects (hypertension, tachycardia, arrhythmias, subarachnoid hemorrhage, particularly with 10% solution)

Drug Interactions

Monoamine oxidase inhibitors (MAOIs): May precipitate severe hypertensive crisis
Tricyclic antidepressants (TCAs): May potentiate pressor response
Atropine and other anticholinergics: May enhance pressor effects and increase intraocular pressure
Beta-blockers (ophthalmic): May cause acute blood pressure changes when combined with systemic absorption

Curated Content: Needs Vetting Before Put to Clinical Use