Combigan (brimonidine tartrate/timolol maleate) is a prescription drug used to treat raised pressure in the eye. Combigan can cause side effects that range from mild to serious. Examples include eye itching, burning, and stinging.

Specifically, Combigan is used in adults and some children to treat:

The active ingredients in Combigan are brimonidine tartrate and timolol maleate. (An active ingredient is what makes a drug work.) The drug comes as an eye drop.

Keep reading to learn about the common, mild, and serious side effects that Combigan can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during their Combigan treatment. Examples of the drug’s more commonly reported side effects include:

  • eye burning, stinging, or itching*
  • eye redness due to widened blood vessels on the eye surface
  • eye inflammation from allergies
  • enlarged follicles (small growths) on the inside of the eyelid and the membrane lining the eye

These side effects are only a few of those possible, and not everyone will experience them. Read the following sections to learn more about side effects.

* To learn more about this side effect, see the Side effects explainedsection below.

Mild side effects have been reported with Combigan. These include:

  • eye burning, stinging, or itching*
  • eye redness due to widened blood vessels on the eye surface
  • eye inflammation from allergies
  • enlarged follicles (small growths) on the inside of the eyelid and the membrane lining the eye
  • eyelid swelling, inflammation (redness or discoloration, heat, pain), or itching
  • eye discharge
  • eye watering
  • eye dryness
  • superficial punctate keratitis (small breaks on the cornea, which is the front of the eye)
  • eye irritation, as if something is in the eye
  • visual disturbance, such as blurry vision
  • headache
  • dry mouth
  • sleepiness*
  • weakness
  • mild allergic reaction*

In most cases, these side effects should be temporary. And some may be managed easily. But if you have symptoms that are ongoing or bothersome, talk with your doctor or pharmacist. And do not stop using Combigan unless your doctor recommends it.

Combigan may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

* To learn more about this side effect, see the Side effects explainedsection below.

Serious side effects have been reported with Combigan, but they weren’t common. These include:

If you develop serious side effects while using Combigan, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the Side effects explainedsection below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Combigan, visit MedWatch.

Combigan is used to treat glaucoma and ocular hypertension in children ages 2 years and older.

The following side effects were reported more commonly in children than in adults in the drug’s studies.

  • reduced alertness
  • sleepiness*

For more information about potential side effects of Combigan in children, talk with your doctor or pharmacist.

* To learn more about this side effect, see the “Side effects explained” section below.

Get answers to some frequently asked questions about Combigan’s side effects.

Does Combigan cause long-term side effects?

It’s possible. Long-term side effects include those that may start at any time while you’re using a drug, even if you’ve used it for a long time. They also include side effects that may not go away, even after you stop using the drug.

Examples of long-term side effects reported in Combigan’s studies include heart failure. Even though Combigan is used in your eye, it can be absorbed into your bloodstream through your eye and affect your heart. Heart failure can develop in some people who use Combigan for a long period of time.

Symptoms of heart failure can include:

  • shortness of breath
  • tiredness
  • swelling of your lower legs or feet
  • sudden weight gain

If you have these symptoms while using Combigan, contact your doctor right away. They’ll likely have you stop using Combigan.

Talk with your doctor to learn more about possible side effects of Combigan and how long they may last.

Can Combigan cause kidney side effects?

It’s not likely. Your kidneys help remove Combigan from your body, among other functions. But kidney side effects weren’t reported in studies of Combigan. Also, kidney side effects haven’t been reported with either brimonidine tartrate or timolol maleate when used separately. (These are the active ingredients in Combigan, which make the drug work.)

If you’re concerned about possible kidney side effects from Combigan, talk with your doctor or pharmacist.

Learn more about some of the side effects Combigan may cause.

Eye burning, stinging, or itching

Eye burning, stinging, and itching were common side effects reported in studies of Combigan. You may have these side effects if the drops irritate your eye when you administer them. These feelings usually wear off after a few minutes.

Eye burning, stinging, or itching also can be symptoms of other Combigan side effects. These include eye inflammation from allergies. They also include superficial punctate keratitis (small breaks on the cornea, which is the front of the eye). With these side effects, you’ll typically also have a painful, red, watery eye and sensitivity to light.

Eye burning, stinging, or itching also can occur if you get an eye infection while using Combigan. This can happen if the bottle of eye drops becomes contaminated with germs that then get in your eye. With an eye infection, your eye typically will be red, sticky, and painful.

What might help

When using Combigan, it’s important that you do not let the tip of the bottle touch your eye, skin, or any other surface. If it does, it could pick up germs that could contaminate the eye drops. This can cause eye infections.

After using the eye drops, always cover the bottle with the cap. Do not use the drops if the solution becomes cloudy or changes color. You should not use the eye drops after the expiration date printed on the bottle. And you should not use the eye drops for more than 28 days after opening the bottle.

If you’re using Combigan and have eye burning, stinging, or itching that’s bothersome or doesn’t go away, talk with your doctor. They may be able to recommend ways to make this treatment more comfortable.

But watch for other symptoms that occur along with eye burning, stinging, or itching. These include eye pain, redness, or a watery or sticky discharge. If you have these, contact your doctor right away. Your doctor will likely have you stop using Combigan. They also may prescribe other medication to treat your symptoms.

Sleepiness

Sleepiness was an uncommon side effect reported in adults in studies of Combigan. But this side effect was commonly reported in children using Combigan, especially in children ages 2–6 years.

Although Combigan is used in your eye, it can enter your bloodstream through your eye. From there, it can reach your brain and cause sleepiness. Feeling sleepy can make it dangerous to do activities such as driving or operating machinery.

What might help

When using Combigan, you should not drive or operate machinery until you know how the medication affects you. Do these activities only when you’re sure you can do so safely.

If you have bothersome sleepiness while using Combigan, talk with your doctor. Your doctor may recommend switching to a different treatment that doesn’t cause this side effect.

Allergic reaction

Like most drugs, Combigan can cause an allergic reaction in some people.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin (usually in your eyelids, lips, hands, or feet)
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an oral antihistamine, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Combigan, they’ll decide whether you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Combigan, they may have you switch to a different treatment.

Keeping track of side effects

During your Combigan treatment, consider making notes about any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were using when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Combigan affects you. They can then use this information to adjust your treatment plan if needed.

Below is important information you should consider before using Combigan.

Warnings

Combigan can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether Combigan is a good treatment option for you.

Talk with your doctor about your health history before you use Combigan. Be sure to tell them if any of the following factors apply to you:

Alcohol and Combigan

No interactions between alcohol and Combigan are known. But alcohol and Combigan can cause some similar side effects. These include low blood pressure, headache, sleepiness, and blurry vision. So you may have an increased risk of these side effects if you drink alcohol while using Combigan.

If you have questions about consuming alcohol during Combigan treatment, talk with your doctor or pharmacist.

Pregnancy and breastfeeding with Combigan

Before starting Combigan treatment, it’s important to talk with your doctor if you’re pregnant, breastfeeding, or planning either.

Pregnancy

It’s not known whether it’s safe to use Combigan during pregnancy. If you’re pregnant or planning to become pregnant, talk with your doctor before starting treatment with Combigan.

Breastfeeding

Combigan is not safe to use while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor about your options.

Like most drugs, Combigan can cause a number of side effects that range from mild to serious. Some are temporary and go away after a few days to weeks. Others may be longer lasting. If you have questions about side effects that Combigan can cause, talk with your doctor.

Examples of questions to help get you started include:

  • Do my other conditions or medications raise my risk of side effects with Combigan?
  • Will I need any monitoring for side effects while using Combigan?
  • Do other medications that could treat my condition have similar side effects?

To learn more about Combigan, see these articles:

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.