Phenylephrine is an alpha-1 agonist.  It has a variety of uses, depending on the route of application.  Pseudoephedrine is another med in this class but is used less in practice and is tightly regulated.

Mechanism of Action

It is a direct-acting sympathomimetic that selectively stimulates alpha-1 adrenergic receptors.

Nasal congestion: Alpha-1 agonists stimulate alpha receptors in the respiratory tract, causing constriction of blood vessels and shrinkage of swollen nasal mucous membranes, thus increasing airway patency and reducing nasal congestion.

For ophthalmic uses, ointment used to facilitate mydriasis and to vasoconstrict conjunctival blood vessels.

Indications for Use

Numerous uses depending on the route. It elevates blood pressure due to vasoconstriction of veins and arteries resulting in raised arterial pressure, thereby used for septic shock and anesthesia.  It may also be used as a decongestant for sympathomimetic relief in upper respiratory infections.  For ophthalmic application, it is used for mydriasis and to vasoconstrict conjunctival blood vessels.  Used in topical application for hemorrhoid relief.

Nursing Considerations

Pseudoephedrine has had recent limitations placed on its use because it is a common ingredient in the illicit manufacturing of the drug methamphetamine. Pharmacies now require individuals to provide identification to purchase pseudoephedrine and must track the number of purchases. As a result, most over-the-counter decongestants now contain phenylephrine.

Monitor for elevated blood pressure, urinary retention, nervousness, or difficulty sleeping.

Do not administer within 2 hours of bedtime due to risk of insomnia.

Pediatrics: There is limited data on whether pseudoephedrine can be used in children under the age of 4 years old, so it should be avoided.

Older adult: It is safe to use in older adult populations, and typically no dosage adjustments are required for renal or liver dysfunction, depending on comorbidities and cardiovascular effects.

Cautions: Phenylephrine and pseudoephedrine both should be used cautiously in clients with glaucoma, hypertension, or an enlarged prostate gland.

Drug interactions:

• contraindicated in clients taking monoamine oxidase inhibitors (MAOIs), an antidepressant, due to hypertensive effects.

Client Teaching

• Clients should be instructed to take medication as prescribed and be careful not to double-dose.
• If they experience nervousness, breathing difficulties, or heart rate changes, they should notify their healthcare provider.
• This med has numerous drug Interactions, ensure to consult with your prescriber if there is any change in your medications.

Phenylephrine Medication Card

Because information about medication is constantly changing, nurses should always consult evidence-based resources to review current recommendations before administering specific medication.

Downloadable file (.docx): Phenylephrine and Pseudoephedrine Medication Card

Interactive Activity