2.1 General Dosing Recommendations

In patients 1 year of age or greater, apply one drop of either phenylephrine hydrochloride ophthalmic solution 2.5% or 10% every 3 to 5 minutes to the conjunctival fornix as required up to a maximum of 3 drops per eye per day.

In order to obtain a greater degree of mydriasis, phenylephrine hydrochloride ophthalmic solution 10% may be needed.

2.2 Dosing in Pediatric Patients Less Than 1 Year of Age

In pediatric patients less than 1 year of age, one drop of phenylephrine hydrochloride ophthalmic solution 2.5% should be instilled at 3 to 5 minute intervals up to a maximum of 3 drops per eye.

4.1 Cardiac and Endocrine Disease

Phenylephrine hydrochloride ophthalmic solution 10% is contraindicated in patients with hypertension or thyrotoxicosis. Phenylephrine hydrochloride ophthalmic solution 2.5% should be used in these patients.

4.2 Pediatric Patients Less Than 1 Year of Age

Phenylephrine hydrochloride ophthalmic solution 10% is contraindicated in pediatric patients less than 1 year of age due to the increased risk of systemic toxicity. Phenylephrine hydrochloride ophthalmic solution 2.5% should be used in these patients [See Dosage and Administration (2.2)].

5.1 Topical Ophthalmic Use Only

Phenylephrine hydrochloride ophthalmic solution 2.5% and 10% is not indicated for injection.

5.2 Cardiovascular Reactions

There have been reports of serious cardiovascular reactions, including ventricular arrhythmias and myocardial infarctions, in patients using phenylephrine 10%. These episodes, some fatal, have usually occurred in patients with pre-existing cardiovascular diseases. Phenylephrine Hydrochloride Ophthalmic Solution, USP 2.5% should be used in these patients.

5.3 Elevation of Blood Pressure

A significant elevation in blood pressure is not common but has been reported following conjunctival instillation of recommended doses of phenylephrine 10%. The risk is less with phenylephrine 2.5%. Caution should be exercised with the use of phenylephrine 10% in pediatric patients less than 5 years of age and patients with hyperthyroidism, or cardiovascular disease. The post-treatment blood pressure of patients with cardiac and endocrine diseases and any patients who develop symptoms should be carefully monitored.

5.4 Rebound Miosis

Rebound miosis has been reported one day after receiving phenylephrine hydrochloride ophthalmic solution, and re-instillation of the drug produced a lesser mydriatic effect.

6.1 Ocular Adverse Reactions

Eye pain and stinging on instillation, temporary blurred vision and photophobia, and conjunctival sensitization may occur.

6.2 Systemic Adverse Reactions

A marked increase in blood pressure has been reported particularly, but not limited to low weight premature neonates, infants and hypertensive patients.

Cardiovascular effects which have been seen primarily in hypertensive patients following topical ocular use of phenylephrine hydrochloride ophthalmic solution 10% include marked increase in blood pressure, syncope, myocardial infarction, tachycardia, arrhythmia and subarachnoid hemorrhage [See Warnings and Precautions (5.2 and 5.3)].

7.1 Agents That May Exaggerate Pressor Responses

Concomitant use of phenylephrine and atropine may enhance the pressor effects and induce tachycardia in some patients. Phenylephrine may potentiate the cardiovascular depressant effects of some inhalation anesthetic agents.

8.1 Pregnancy

Animal reproduction studies have not been conducted with topical phenylephrine. It is also not known whether phenylephrine can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Phenylephrine hydrochloride should be given to a pregnant woman only if clearly needed.

8.3 Nursing Mothers

It is not known whether this drug is excreted in human breast milk. Because many drugs are excreted in human milk, caution should be exercised when phenylephrine hydrochloride ophthalmic solution 2.5% and 10% is administered to a nursing woman.

8.4 Pediatric Use

Phenylephrine hydrochloride ophthalmic solution 10% is contraindicated in pediatric patients less than 1 year of age [See Contraindications (4.2)].

8.5 Geriatric Use

No overall differences in safety and effectiveness have been observed between elderly and younger adult patients.

12.1 Mechanism of Action

Phenylephrine hydrochloride is an α-1 adrenergic agonist drug that is used in ophthalmology mainly for its mydriatic effect. After topical application to the conjunctiva, phenylephrine acts directly on α-adrenergic receptors in the eye, producing contraction of the dilator muscle of the pupil and constriction of the arterioles in the conjunctiva.

12.2 Pharmacodynamics

Maximal mydriasis occurs in 20 to 90 minutes with recovery after 3 to 8 hours.

Systemic absorption of sufficient quantities of phenylephrine may lead to systemic α-adrenergic effects, such as rise in blood pressure which may be accompanied by a reflex atropine-sensitive bradycardia.

12.3 Pharmacokinetics

The systemic exposure following topical administration of phenylephrine hydrochloride ophthalmic solution has not been studied. A higher systemic absorption is expected for the 10% solution than the 2.5% solution and when the corneal barrier function is compromised.