Phenylephrine
Phenylephrine is a selective alpha-1 adrenergic receptor agonist that causes vasoconstriction, increasing blood pressure and reducing nasal congestion. It is used both in hospital settings as a vasopressor to treat hypotension and in over-the-counter products for temporary relief of nasal or eye symptoms.
Phenylephrine is a vasoconstrictor medication used to raise blood pressure during surgery or sepsis, and to relieve nasal or ocular congestion.
Key facts at a glance
- ATC
- C01CA06
- RxNorm
- unknown
- Generic
- Phenylephrine
- Class
- atc-c01
- Brands
- Wal-Dryl-D, Wal-Four, Wal-Phed PE, Dallergy Reformulated Nov 2011, Sudo-Tab, Nasopen PE, Biorphen, Omidria, Vazculep, Wal-Dryl PE, RectiCare Advance Cream, Benadryl Allergy Plus Congestion, Neo-Synephrine, Mydfrin, Ventuss
- Availability
- otc
- Pregnancy
- C
- Lactation
- caution
- Half-life (h)
- 2
- Onset (min)
- 10
- Duration (h)
- 4
- Routes
- oral, rectal, ophthalmic, topical, nasal
- Forms
- tablet, capsule, nasal spray, nasal drop, ophthalmic drop, topical cream, suppository
- Regions
- United States, Canada, United Kingdom, Australia, New Zealand
- Monitoring
- blood pressure, heart rate
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 10mg every 4 hours as needed
- Maximum
- consult physician
- Frequency
- every 4 hours (max 60mg/24h)
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 5mg every 4 hours as needed
- Maximum
- consult physician
- Frequency
- every 4 hours (max 30mg/24h)
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 10mg every 4 hours as needed
- Maximum
- consult physician
- Frequency
- every 4 hours (max 60mg/24h)
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
7 groupspregnancy
first trimesteruse lowest effective dose
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring recommended
Use with caution and monitor for adverse effects.
pregnancy
third trimesteravoid prolonged use
use only if clearly needed, avoid near delivery
monitor uterine blood flow and fetal heart rate
Use with caution and monitor for adverse effects.
lactation
breastfeedingavoid high doses
use with caution, monitor infant for irritability or sleep changes
observe infant for adverse effects
Use with caution and monitor for adverse effects.
geriatric
elderlystart with lowest dose
use with caution due to increased cardiovascular sensitivity
monitor blood pressure and heart rate
Use with caution and monitor for adverse effects.
pediatric_age
children under 12weight-based dosing, avoid adult formulations
use pediatric-specific formulations, avoid in children under 2 years
monitor for irritability, insomnia, and cardiovascular effects
Use with caution and monitor for adverse effects.
renal_impairment
severe renal impairmentreduce dose or avoid
use with caution, may require dose adjustment
monitor renal function and blood pressure
Use with caution and monitor for adverse effects.
hepatic_impairment
severe hepatic impairmentuse with caution
use lower doses, monitor response
monitor blood pressure and hepatic function
Use with caution and monitor for adverse effects.
Statistics and clinical data
Commonly prescribed since
General prescribing information
Drug class
Drug class information
Common uses
Common therapeutic uses
Mechanism of action
Pharmacological mechanism
Treatment of hypotension during anesthesia or shock states, nasal congestion from colds or allergies, and ocular procedures requiring pupil dilation. Also used for supraventricular tachycardia when vagal maneuvers are insufficient.
Acts primarily on alpha-1 adrenergic receptors in blood vessel walls, causing smooth muscle contraction and vasoconstriction. This increases systemic vascular resistance and blood pressure. In nasal formulations, it shrinks swollen mucous membranes to relieve congestion.
Use with caution in patients with cardiovascular disease, hypertension, or thyroid disorders. Avoid in patients taking MAO inhibitors due to risk of severe hypertensive crisis. May cause rebound congestion with prolonged nasal use. Monitor blood pressure closely during IV administration.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy