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Generic name: dorzolamide hydrochloride and timolol maleate

What is Cosopt?

Cosopt is an eyedrop. It contains dorzolamide hydrochloride, which is an ophthalmic carbonic anhydrase inhibiting drug. It also contains timolol maleate, which is a beta-blocking drug. Both drugs work to lower pressure in the eye, but in different ways.

Cosopt is a medicine for lowering pressure in the eye in people with open-angle glaucoma or ocular hypertension. It is used when a beta-blocker eyedrop alone is not adequate to control eye pressure.

What should I know about high pressure in the eye?

People with open-angle glaucoma or ocular hypertension have pressures in one or both of their eye(s) that are too high for them.

High pressure in the eye may damage the optic nerve. This may lead to loss of vision and possible blindness. There generally are few symptoms that you can feel to tell you whether you have high pressure within your eye. Your doctor needs to examine your eyes to determine this. If you have high pressure in your eye, you will need your pressure checked and your eyes examined regularly.

Who should not take Cosopt?

Do not use Cosopt if you have:

  • or have ever had asthma,
  • severe lung problems (such as chronic obstructive pulmonary disease),
  • heart problems, including slow or irregular heartbeat or heart failure,
  • allergies to any of its ingredients. See the ingredients list at the end of the guide.

If you are not sure whether you should use Cosopt, contact your doctor or pharmacist.

What should I tell my healthcare provider before taking Cosopt?

Tell your doctor:

  • if you are pregnant or plan to become pregnant,
  • if you are breast-feeding or intend to breast-feed,
  • about any medical problems you have now or had in the past, especially heart problems or breathing problems including asthma,
  • if you now have or had in the past kidney or liver problems,
  • if you have diabetes, thyroid disease or muscle weakness,
  • about all medicines that you are taking or plan to take, including those you can get without a prescription,
  • about any allergies including allergies to any medications, especially sulfa drugs,
  • if you develop an eye infection, develop a red or swollen eye or eyelid, receive an eye injury, have eye surgery, or develop new or worsening eye symptoms,
  • if you plan on having any type of surgery.

How should I take Cosopt?

Cosopt is an eyedrop. The usual dose is one drop in the morning and one drop in the evening. Your doctor will tell you if just one or both eyes are to be treated.

If you are using Cosopt with another eyedrop, the eyedrops should be used at least 5 minutes apart. It is very important to use your medication exactly as directed by your doctor. If you stop using your medicine, contact your doctor immediately.

COSOPT contains a preservative called benzalkonium chloride. This preservative may be absorbed by soft contact lenses. Contact lenses should be removed before using Cosopt. The lenses can be placed back into your eyes 15 minutes after using the eyedrops.

Do not allow the tip of the bottle to touch the eye or areas around the eye. The bottle may become contaminated with bacteria. This can cause eye infections leading to serious damage to the eye, even loss of vision. Keep the tip of the bottle away from contact with any surface to avoid contamination.

Can I use Cosopt with other medicines?

Tell your doctor or pharmacist about all drugs that you are using or plan to use. This includes other eyedrops and drugs obtained without a prescription. This is particularly important if you are taking medicine to lower blood pressure or to treat heart disease, medicines to treat diabetes, or if you are taking large doses of aspirin.

Ask your doctor's advice about taking Cosopt if you are also using:

  • oral carbonic anhydrase inhibitors (for example, acetazolamide, Diamox)
  • oral beta-blockers (for example, propranolol, Inderal)
  • calcium antagonists (for example, nifedipine, Procardia)
  • catecholamine-depleting drugs (for example, reserpine)
  • digitalis in combination with calcium antagonists (for example, Lanoxin with Procardia)
  • quinidine (for example, Cardioquin)
  • clonidine (for example, Catapres)
  • injectable epinephrine (for example, EpiPen)
  • certain antidepressants (for example, Prozac)

Your doctor or pharmacist can tell you if any of the drugs you are using are in the above list.

What are the possible side effects of Cosopt?

Any medicine may have unintended or undesirable effects. These are called side effects. Side effects may not occur, but if they do occur, you may need medical attention. The most common side effects you may experience are:

  • eye symptoms such as burning and stinging, redness of the eye(s), blurred vision, tearing or itching.
  • a bitter, sour or unusual taste after putting in your eyedrops.

Other side effects may occur rarely, and some of these may be serious. Tell your doctor right away if your experience:

  • shortness of breath
  • visual changes
  • an irregular heartbeat and/or a slowing of your heart rate
  • severe skin reactions

The above list is not a complete list of side effects reported with Cosopt. Your doctor can discuss with you a more complete list of side effects. Please tell your doctor [or pharmacist] promptly about any of these or any other unusual symptom.

What should I do in case of an overdose?

If you swallow the contents of the bottle, contact your doctor immediately. Among other effects, you may feel light-headed, have difficulty breathing, or feel your heart rate has slowed.

General information about the safe and effective use of Cosopt

Do not use Cosopt for a condition for which it was not prescribed. Do not give Cosopt to other people, even if they have the same condition you have. It may harm them.

How should I store Cosopt?

  • Keep your medicine in a safe place where children cannot reach it.
  • Store Cosopt at room temperature 20° to 25°C (68° to 77°F) [see USP Controlled Room Temperature].
  • Protect the bottle from light.
  • Do not use your medicine after the expiration date on the bottle.

What are the ingredients in Cosopt?

Active ingredients: dorzolamide hydrochloride, timolol maleate.

Inactive ingredients: sodium citrate, hydroxyethylcellulose, sodium hydroxide, mannitol, water for injection and benzalkonium chloride added as a preservative.

Source: National Library of Medicine. Last updated January 31, 2018.