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Phenylephrine (Ophthalmic)



(fen il EF rin)

Index Terms

  • Phenylephrine HCl
  • Phenylephrine Hydrochloride

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Solution, Ophthalmic, as hydrochloride:

Altafrin: 2.5% (15 mL); 10% (5 mL) [contains benzalkonium chloride]

Mydfrin: 2.5% (3 mL [DSC], 5 mL [DSC]) [contains benzalkonium chloride, edetate disodium]

Neofrin: 2.5% (15 mL [DSC]) [contains benzalkonium chloride, edetate disodium, sodium bisulfite]

Neofrin: 10% (5 mL [DSC]) [contains benzalkonium chloride]

Generic: 2.5% (2 mL, 3 mL, 5 mL, 15 mL); 10% (5 mL)

Solution, Ophthalmic, as hydrochloride [preservative free]:

Generic: 2.5% (1 ea)

Brand Names: U.S.

  • Altafrin
  • Mydfrin [DSC]
  • Neofrin [DSC]

Pharmacologic Category

  • Alpha-Adrenergic Agonist
  • Ophthalmic Agent, Antiglaucoma
  • Ophthalmic Agent, Mydriatic


Potent, direct-acting alpha-adrenergic agonist with virtually no beta-adrenergic activity; produces local vasoconstriction


Minimal systemic absorption (Kumar, 1986)

Onset of Action

Mydriasis: 15 minutes; maximal mydriasis: 20 to 90 minutes; time to recovery: 3 to 8 hours

Time to Peak

Plasma: ≤20 minutes (Kumar, 1986)

Use: Labeled Indications

Mydriasis: To dilate the pupils


2.5% solution: There are no contraindications listed in the manufacturer’s labeling.

10% solution: Hypertension; thyrotoxicosis; infants younger than 1 year

Documentation of allergenic cross-reactivity for ophthalmic decongestants is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Dosing: Adult

Mydriasis: Ophthalmic: 2.5% or 10% solution: Instill 1 drop every 3 to 5 minutes as needed (maximum dose: 3 drops per eye). If necessary, dose may be repeated.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Mydriasis: Ophthalmic:

Infants: 2.5% solution: Instill 1 drop every 3 to 5 minutes as needed (maximum dose: 3 drops per eye)

Children and Adolescents: 2.5% or 10% solution: Refer to adult dosing

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.


Ophthalmic: Wash hands before and after application. For topical ophthalmic use only; to avoid contamination, do not touch dropper tip to eyelids or other surfaces when placing drops in eyes. Solution should be applied to the conjunctival fornix unless otherwise directed. Protect eyes from bright illumination while pupils are dilated.


Ophthalmic solution: 2.5% and 10%: Refer to product labeling. Some products are labeled to store at room temperature; others should be stored under refrigeration at 2˚C to 8˚C (36˚F to 46˚F). Do not use solution if brown or contains a precipitate.

Drug Interactions

Alpha1-Blockers: May diminish the vasoconstricting effect of Alpha1-Agonists. Similarly, Alpha1-Agonists may antagonize Alpha1-Blocker vasodilation. Monitor therapy

AtoMOXetine: May enhance the hypertensive effect of Sympathomimetics. AtoMOXetine may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Cannabinoid-Containing Products: May enhance the tachycardic effect of Sympathomimetics. Exceptions: Cannabidiol. Monitor therapy

Doxofylline: Sympathomimetics may enhance the adverse/toxic effect of Doxofylline. Monitor therapy

Ergot Derivatives: May enhance the hypertensive effect of Alpha1-Agonists. Ergot Derivatives may enhance the vasoconstricting effect of Alpha1-Agonists. Exceptions: Ergoloid Mesylates; Nicergoline. Avoid combination

Iobenguane I 123: Sympathomimetics may diminish the therapeutic effect of Iobenguane I 123. Avoid combination

Linezolid: May enhance the hypertensive effect of Sympathomimetics. Management: Reduce initial doses of sympathomimetic agents, and closely monitor for enhanced pressor response, in patients receiving linezolid. Specific dose adjustment recommendations are not presently available. Consider therapy modification

MAO Inhibitors: May enhance the hypertensive effect of Alpha1-Agonists. While linezolid is expected to interact via this mechanism, management recommendations differ from other monoamine oxidase inhibitors. Refer to linezolid specific monographs for details. Exceptions: Linezolid; Tedizolid. Avoid combination

Sympathomimetics: May enhance the adverse/toxic effect of other Sympathomimetics. Monitor therapy

Tedizolid: May enhance the hypertensive effect of Sympathomimetics. Tedizolid may enhance the tachycardic effect of Sympathomimetics. Monitor therapy

Tricyclic Antidepressants: May enhance the vasopressor effect of Alpha1-Agonists. Tricyclic Antidepressants may diminish the vasopressor effect of Alpha1-Agonists. Monitor therapy

Adverse Reactions

Frequency not defined. Systemic effects are rare at normal dosages.

Ophthalmic: Burning sensation of eyes, eye irritation, miosis (rebound), visual disturbance, vitreous opacity (transient)

<1% (Limited to important or life-threatening): Cardiac arrhythmia, hypertension, myocardial infarction, subarachnoid hemorrhage, syncope


Concerns related to adverse effects:

• Cardiovascular events: Although rare, ventricular arrhythmias and myocardial infarction (including fatalities) have been reported with use of the 10% solution. Patients with preexisting cardiovascular disease may be at increased risk; consider use of 2.5% solution in these patients.

• Hypertension: Significant blood pressure elevation has been reported with the 10% solution; risk is less with 2.5% solution. Use caution when using 10% solution in children <5 years of age, patients with hyperthyroidism or patients with cardiovascular disease. Carefully monitor posttreatment blood pressure in patients with endocrine or cardiac diseases, or any patient who develops symptoms during treatment.

• Rebound miosis: Has been reported 1 day after treatment; reinstallation of the drug produced a lesser mydriatic effect.

Special populations:

• Pediatrics: The 10% should NOT be used in infants <1 year of age (2.5% solution should be used). Use caution when using 10% solution in children <5 years of age.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Other warnings/precautions:

• Appropriate use: For ophthalmic use only; not for injection.

• Sulfites: Some products contain sulfites which may cause allergic reactions in susceptible individuals.

Pregnancy Risk Factor


Pregnancy Considerations

Animal reproduction studies have not been conducted; therefore, the manufacturer classifies phenylephrine ophthalmic as pregnancy category C. When administered intravenously, phenylephrine crosses the placenta (refer to the Phenylephrine (Systemic) monograph for details). The amount of phenylephrine available systemically following ophthalmic application is generally less in comparison to oral or IV doses.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience stinging, floaters, enlarged pupils, or sensitivity to light. Have patient report immediately to prescriber vision changes, eye pain, or severe eye irritation (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.