This medication is a combination of two different medications: brimonidine tartrate and timolol maleate

Use as prescribed by doctor

side effects that may occur include dry mouth; headache; itching, burning, stinging, redness, or dryness of the eye; blurred vision; feeling of something in the eye; or drowsiness. If COMBIGAN side effects continue or are bothersome, check with your doctor. CHECK WITH YOUR DOCTOR AS SOON AS POSSIBLE if you experience COMBIGAN side effects like dizziness, stomach discomfort, eyelid crusting, anxiety, palpitations, sensitivity to light, nasal dryness. If you notice other COMBIGAN side effects not listed above, contact your doctor, nurse, or pharmacist.

There may be an interaction between brimonidine tartrate - timolol maleate eye drops and any of the following:
alcohol
anaesthetics
barbiturates (e.g., butalbital, phenobarbital)
benzodiazepines (e.g., diazepam, lorazepam)
beta-adrenergic blockers (e.g., atenolol, metoprolol, propranolol)
calcium channel blockers (e.g., nifedipine, verapamil)
cardiac glycosides (e.g., digoxin)
catecholamine-depleting medications (e.g., guanethidine, reserpine)
clonidine
epinephrine
high blood pressure medications (e.g., losartan)
monoamine oxidase inhibitors (MAOIs; e.g., phenelzine, tranylcypromine)
opiate medications (e.g., codeine, hydrocodone, morphine)
quinidine
tricyclic antidepressants (e.g., amitriptyline, clomipramine)

If you suspect an overdose call the emergency department or your doctor immediately.

Do not double doses to make up for a missed one

used to reduce the pressure inside the eye for people with open-angle glaucoma or intraocular hypertension (increased pressure in the eye) for people who do not have a complete response to treatment with only one medication

Store in a cool dry place