← Search & browse all drugs
RESPIRATORY SYSTEM › NASAL PREPARATIONS › DECONGESTANTS AND OTHER NASAL PREPARATIONS FOR TOPICAL USE › Sympathomimetics, plain
phenylephrine
R01AA04
Forms & Strengths
- Nasal spray: 0.125%, 0.25%, 0.5%, 1%
- Nasal drops: 0.125%, 0.25%, 1%
- Ophthalmic solution: 2.5%, 10%
- Injection: 10 mg/mL
Adult Dosing
- Nasal decongestant: 2-3 sprays or drops of 0.25%-0.5% solution in each nostril every 4 hours as needed
- Mydriasis: 1 drop of 2.5% or 10% ophthalmic solution into conjunctival sac
- Hypotension (IV): 50-250 mcg bolus or 20-100 mcg/min continuous infusion, titrated to effect
Pediatric Dosing
- Nasal decongestant (Children 6-12 years): 2-3 drops of 0.25% solution in each nostril every 4 hours as needed
- Nasal decongestant (Children 2-6 years): Use only as directed by a physician (typically 0.125% solution)
- Ophthalmic (Infants): 2.5% solution preferred; 10% generally contraindicated due to systemic toxicity risks
Indications
- Nasal congestion associated with rhinitis, sinusitis, and common cold
- Mydriasis for ophthalmic diagnostic procedures and surgeries
- Treatment of hypotension, particularly during anesthesia or associated with vasodilation
Mechanism of Action
- Direct-acting sympathomimetic amine
- Potent alpha-1 adrenergic receptor agonist
- Causes vasoconstriction of arterioles in nasal mucosa, conjunctiva, and systemic vasculature, leading to decreased congestion, mydriasis, and increased blood pressure
Contraindications
- Hypersensitivity to phenylephrine or any component of the formulation
- Severe hypertension
- Ventricular tachycardia
- Narrow-angle glaucoma (ophthalmic use)
Adverse Reactions
- Transient stinging or burning (nasal/ophthalmic)
- Rebound congestion (rhinitis medicamentosa) with prolonged nasal use
- Hypertension
- Reflex bradycardia
- Arrhythmias
- Blurred vision and increased intraocular pressure (ophthalmic)
Drug Interactions
- Monoamine oxidase inhibitors (MAOIs): May cause severe hypertensive crisis; avoid concurrent use or within 14 days
- Vasopressor agents and ergot alkaloids: Potentiates vasoconstrictive and hypertensive effects
- Beta-blockers: May antagonize cardiac effects or lead to severe hypertension due to unopposed alpha-1 vasoconstriction
- Tricyclic antidepressants: May potentiate pressor response of phenylephrine
Curated Content: Needs Vetting Before Put to Clinical Use