PlainMeds provides educational information only. This is not medical advice. Always consult your doctor or pharmacist.

Prescription medication · Alpha-2 Agonist (Ophthalmic)

brimonidine ophthalmic

Also sold as Alphagan P. Alphagan P eye drops are used to lower high pressure inside your eye.

Data updated 2026-05-15

1
InteractionFew interactions
99% less
Generic vs brandHuge savings
$37.34
Brand price (NADAC)

What the data shows

brimonidine ophthalmic (Alphagan P) is a prescription Alpha-2 Agonist (Ophthalmic), whose generic costs a fraction of the brand (about 99% less).

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

brimonidine ophthalmic (Alphagan P) is a prescription Alpha-2 Agonist (Ophthalmic). Alphagan P eye drops are used to lower high pressure inside your eye.

Alphagan P eye drops help lower pressure in the eye. It is used for people with open-angle glaucoma or ocular hypertension.

Drug Pricing (NADAC)

Brand Price

$37.34/unit

Generic Price

$0.46/unit

Generic Savings

99%

Generic Available

Yes (20 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

View Alternatives → Compare with Another Drug →

What it does

Alphagan P eye drops are used to lower high pressure inside your eye.

Common side effects

Allergic conjunctivitis (eye allergy), Eye redness, Eye itching

Key warnings

Alphagan P may worsen problems caused by poor blood flow.

The sections below are summarized in plain English from brimonidine ophthalmic's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Alphagan P is an alpha-2 adrenergic agonist. It works by decreasing the amount of fluid your eye makes. It also helps increase the amount of fluid that drains from your eye, which lowers eye pressure.

How to Take It

Use one drop of Alphagan P in the affected eye(s) three times a day. Space each dose about 8 hours apart. If you use other eye drops, wait at least 5 minutes before using them. This will help each medicine work correctly.

This is a plain-language summary of brimonidine ophthalmic's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.

Pregnancy & Breastfeeding

It is not known if Alphagan P will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. It is not known if Alphagan P passes into breast milk. Talk to your doctor before breastfeeding.

This is a plain-language summary of brimonidine ophthalmic's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.

Missed Dose

If you miss a dose, use it as soon as you remember. Then, continue with your regular schedule.

This is a plain-language summary of brimonidine ophthalmic's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.

Storage

Store Alphagan P at room temperature, between 59°F and 77°F.

Serious Warnings

Alphagan P may worsen problems caused by poor blood flow. Use caution if you have depression, problems with blood flow to your brain or heart, Raynaud’s phenomenon, low blood pressure when standing up, or thromboangiitis obliterans. Do not touch the tip of the container to your eye or any other surface. This can cause the solution to become contaminated and lead to serious eye damage and vision loss.

Known Drug Interactions

( 7.2 ) Tricyclic antidepressants may potentially blunt the hypotensive effect of systemic clonidine. 7.3 Tricyclic Antidepressants Tricyclic antidepressants have been reported to blunt the hypotensive effect of systemic clonidine.

Mechanism: Both medications work in a similar way to lower blood pressure, which may cause an additive effect when used together.

What to do: Your healthcare provider should monitor your blood pressure closely if you are using both of these medications.

This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.

Common Questions

Can I use Alphagan P if I am under 2 years old?
No, you should not use Alphagan P if you are younger than 2 years old.
What should I do if my eyes get irritated after using Alphagan P?
Tell your doctor if you have eye irritation, redness, itching, or other eye problems.
Can Alphagan P affect my blood pressure?
Yes, Alphagan P can sometimes lower blood pressure. Talk to your doctor if you have concerns.
Can I use Alphagan P with other eye drops?
Yes, but wait at least 5 minutes between using Alphagan P and other eye drops.
What if the Alphagan P solution changes color?
The solution should be clear with a greenish-yellow color. If it changes color or becomes cloudy, do not use it.
Can I drive after using Alphagan P?
Alphagan P may cause drowsiness or blurred vision in some people. Be careful driving or operating machinery until you know how this medicine affects you.
What should I do if I accidentally swallow Alphagan P?
Seek medical attention immediately or call a poison control center.
Can I wear contact lenses while using Alphagan P?
Ask your doctor if you can wear contact lenses while using Alphagan P.
Is it okay to share my Alphagan P eye drops with someone else?
No, never share your eye drops with anyone else, even if they have the same condition.
What should I do if I experience an allergic reaction to Alphagan P?
Stop using Alphagan P and seek immediate medical attention if you have signs of an allergic reaction, such as rash, itching, swelling, or trouble breathing.
What are the common side effects of brimonidine ophthalmic?
The most commonly reported side effects of brimonidine ophthalmic include Allergic conjunctivitis (eye allergy), Eye redness, Eye itching, Burning sensation in the eye, Small bumps on the conjunctiva (conjunctival folliculosis). Always consult your healthcare provider about potential side effects.
Does brimonidine ophthalmic interact with other medications?
Yes, brimonidine ophthalmic has 1 known drug interactions. Notable interactions include clonidine. Always inform your doctor about all medications you are taking.
What drug class is brimonidine ophthalmic?
brimonidine ophthalmic belongs to the Alpha-2 Agonist (Ophthalmic) drug class. It requires a prescription (Rx). Alphagan P eye drops are used to lower high pressure inside your eye.
Is there a generic version of brimonidine ophthalmic?
Yes, generic brimonidine ophthalmic is available from 20 manufacturers. The generic costs $0.46 per unit compared to $37.34 for the brand version, saving approximately 99%. Pricing is based on NADAC (National Average Drug Acquisition Cost) data from CMS.
Is brimonidine ophthalmic safe during pregnancy?
It is not known if Alphagan P will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant. Always consult your healthcare provider before using any medication during pregnancy or breastfeeding.

Related Medications in Alpha-2 Agonist (Ophthalmic)

Other drugs grouped near brimonidine ophthalmic - same-class peers and common alternatives.

Compare brimonidine ophthalmic vs aflibercept side-by-side →

Medication Guides

Save on brimonidine ophthalmic

Compare prices and find discounts at pharmacies near you. Free coupons can save up to 80% on prescriptions.

Disclosure: This link may earn us a commission at no extra cost to you. See our terms.

What the FDA Data Shows for brimonidine ophthalmic

The FDA label for brimonidine ophthalmic (sold under brand names such as Alphagan P) classifies it as a prescription-only medication in the Alpha-2 Agonist (Ophthalmic) class. Alphagan P eye drops are used to lower high pressure inside your eye. Official labeling lists 8 commonly reported side effects, including Allergic conjunctivitis (eye allergy), Eye redness, Eye itching.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. Voluntary reports accumulate over the lifetime of a drug and reflect wide-ranging clinical use. The database also lists 1 documented drug interaction derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.46 versus $37.34 for the brand - a 99% generic savings.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC).

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.

Last updated: September 18, 2025

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.

All federal data sources used on this page