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CARDIOVASCULAR SYSTEM › CARDIAC THERAPY › CARDIAC STIMULANTS EXCL. CARDIAC GLYCOSIDES › Adrenergic and dopaminergic agents
phenylephrine
C01CA06
Forms & Strengths
- Injection: 10mg/mL
- Oral: 10mg, 15mg, 20mg, 30mg, 40mg tablets or capsules
- Topical: 0.12%, 0.25%, 0.5%, 1% ophthalmic solutions
- Nasal: 0.125%, 0.25%, 0.5%, 1% sprays
- Rectal: 10mg, 20mg suppositories
Adult Dosing
- Hypotension: 10mg IV bolus, repeat as needed
- Nasal decongestion: 0.125% to 1% nasal spray, 2-3 sprays per nostril
- Ophthalmic: 0.12% to 10% eye drops, 1-2 drops per eye
- Oral: 10-20mg every 4 hours
Pediatric Dosing
- Nasal decongestion (6-12 years): 0.125% nasal spray, 1-2 sprays per nostril
- Nasal decongestion (2-5 years): 0.125% nasal spray, 1 spray per nostril
- Ophthalmic: 0.12% to 1% eye drops, 1 drop per eye, adjust according to age and weight
Indications
- Vasopressor support in hypotension
- Nasal decongestion
- Ophthalmic for mydriasis
- Relief of sinus congestion
- Hemorrhoid treatment
Mechanism of Action
- Alpha-1 adrenergic receptor agonist
- Directly stimulates alpha-1 receptors
- Increases vascular smooth muscle contraction
- Causes vasoconstriction, increasing blood pressure
Contraindications
- Hypersensitivity to phenylephrine or other sympathomimetics
- Severe hypertension
- Coronary artery disease
- Cardiac arrhythmias
- Narrow-angle glaucoma
Adverse Reactions
- Hypertension
- Tachycardia
- Headache
- Nausea
- Vomiting
- Urinary retention
- Ocular irritation
Drug Interactions
- Tricyclic antidepressants: increased risk of hypertension
- MAOIs: increased risk of hypertensive crisis
- Beta blockers: increased risk of unopposed alpha-adrenergic stimulation
- Anesthetics: increased risk of arrhythmias
- Ergot alkaloids: increased risk of peripheral vasoconstriction
Curated Content: Needs Vetting Before Put to Clinical Use