Brimonidine (Alphagan P) Side Effects

Possible side effects of brimonidine are listed below. Tell your doctor if these side effects are severe or do not go away in a few days.

• Temporary eye irritation (redness, itching, burning, or stinging)
• Blurred vision
• Eye dryness
• Watery eyes
• Swelling or redness of the eyelids
• Sensitivity to light
• Drowsiness
• Headache
• Sleep difficulties
• Dry mouth
• Heartburn
• Flu-like symptoms or cold symptoms (runny nose, sore throat, cough, pain or pressure in the face)

Rarely, brimonidine can cause more serious side effects. Seek immediate medical help if you have the following serious symptoms:

• Skin rash, hives, itching
• Difficulty breathing
• Visual field defect (blind spot)
• Seeing flashes of light or specks
• Dizziness
• Nausea
• Fainting

The above list may not include all the potential adverse effects of brimonidine. Contact your healthcare professional if the side effects are unusual or severe or they do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Brimonidine (Alphagan P) Overdose: In case of accidental oral ingestion of brimonidine, contact your doctor immediately. You can also call the National Poison Control Center at 1-800-222-1222. Call 911 if a person cannot be awakened, has trouble breathing, has collapsed, or has had a seizure. 

Systemic exposure to brimonidine can result in hypotension (low blood pressure) in adults. Treatment for an oral overdose includes supportive and symptomatic therapy. In infants with congenital glaucoma, brimonidine tartrate ophthalmic solution can cause respiratory depression, slowed heart rate, low blood pressure, low body temperature, low muscle tone, pale skin, drowsiness, lethargy, and coma. This medication is contraindicated (not for use) in pediatric patients below 2 years of age.

Source: FDA