Cosopt, Cosopt Pf

Introduction

Written by Patricia Weiser, PharmD
Medically reviewed by Melissa Badowski, PharmD, MPH, FCCP
Updated on July 26, 2023

Dorzolamide/timolol (dor ZOLE a mide and TYE moe lole) is a generic medication prescribed for glaucoma. Dorzolamide belongs to a group of drugs called carbonic anhydrase inhibitors, and timolol belongs to the beta-blocker group of drugs.

Specifically, the Food and Drug Administration (FDA) has approved dorzolamide/timolol to lower eye pressure in certain people with open-angle glaucoma or ocular hypertension.

Common questions about dorzolamide/timolol

Below you’ll find answers to a few commonly asked questions about dorzolamide/timolol.

What brand names are available for dorzolamide/timolol?

Dorzolamide/timolol is available as the brand-name drug Cosopt. Dorzolamide/timolol is a generic medication. Generic drugs usually cost less than brand-name drugs.

If you’d like to use the brand-name version of dorzolamide/timolol, talk with your doctor.

Is dorzolamide/timolol preservative-free?

No, dorzolamide/timolol eye drops aren’t preservative-free. They contain a preservative called benzalkonium chloride. This is to help prevent the growth of germs in the eye drop bottle, which you’ll reuse for each dose. Without the preservative, your eye drops can become contaminated. This can lead to eye infections. 

However, Cosopt PF is available as a brand-name and preservative-free version of dorzolamide/timolol eye drops. Cosopt PF comes in single-use containers that you use for one dose in one or both eyes and then discard.

Talk with your doctor if you’re interested in trying Cosopt PF instead of dorzolamide/timolol eye drops.

Note: If you wear soft contact lenses, these lenses can absorb benzalkonium chloride. To avoid this, you should remove your contacts before using dorzolamide/timolol eye drops. Wait 15 minutes after using the eye drops before reinserting your contact lenses.

How does dorzolamide/timolol work? And how long does it take to start working?

Dorzolamide/timolol is used to lower intraocular pressure (IOP), which is the pressure inside your eye. It works by reducing the amount of fluid made within your eye.

Dorzolamide/timolol starts working right away. Your eye doctor will check your IOP during eye exams throughout treatment. This is to determine how well the drug is working for you.

If you’d like to know more about this, talk with your doctor.

Interactions and warnings for dorzolamide/timolol

Below, you’ll find information about dorzolamide/timolol’s possible interactions and warnings.

Interactions of dorzolamide/timolol

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you use dorzolamide/timolol, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for dorzolamide/timolol” section below.

Warnings for dorzolamide/timolol

Some people should not use dorzolamide/timolol and others should use it cautiously.

Dorzolamide/timolol could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether dorzolamide/timolol is a safe option for you.

Ask your doctor about specific warnings for dorzolamide/timolol, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Dorzolamide/timolol can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to dorzolamide/timolol or any of its ingredients, your doctor will likely not prescribe dorzolamide/timolol. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to dorzolamide/timolol, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of dorzolamide/timolol

If you use dorzolamide/timolol, you should not use more dorzolamide/timolol than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve used too much dorzolamide/timolol, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and dorzolamide/timolol

Information about using dorzolamide/timolol while pregnant or breastfeeding is described below.

Dorzolamide/timolol and pregnancy

It’s unknown whether dorzolamide/timolol is safe to use during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before using this medication.

If you’re planning a pregnancy or can become pregnant, also talk with your doctor about glaucoma or ocular hypertension treatment options during pregnancy. Together, you can discuss the possible risks and benefits of your treatment options and decide whether you should use dorzolamide/timolol during pregnancy.

Dorzolamide/timolol and breastfeeding

It’s unknown whether dorzolamide/timolol should be used while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before using this medication.

Uses of dorzolamide/timolol

The Food and Drug Administration (FDA) approves prescription drugs such as dorzolamide/timolol for certain conditions. Approved uses for dorzolamide/timolol are described below.

Use for lowering eye pressure

Doctors may prescribe dorzolamide/timolol eye drops for lowering eye pressure. Eye pressure is also known as intraocular pressure (IOP), which is the pressure inside your eye. The drug is used for this purpose in certain adults and children ages 2 years and older. It’s usually prescribed as a long-term treatment.

Specifically, dorzolamide/timolol is used for this purpose in people with open-angle glaucoma or ocular hypertension. More specifically, the drug is usually prescribed for people who’ve already tried beta-blocker eye drops. Dorzolamide/timolol is prescribed after a beta-blocker eye drop hasn’t worked well enough.

With these conditions, the pressure inside your eye becomes too high. If untreated, this can lead to vision problems, such as vision loss. Your eye doctor can measure your eye pressure during eye exams.

Side effects of dorzolamide/timolol

Dorzolamide/timolol may cause mild or serious side effects. More common mild side effects of dorzolamide/timolol and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about dorzolamide/timolol’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for dorzolamide/timolol listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of dorzolamide/timolol are listed below.

This article doesn’t include all possible mild side effects of the drug. To learn more about dorzolamide/timolol’s side effects, refer to the prescribing information for dorzolamide/timolol listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Dorzolamide/timolol eye drops’ mild side effects include:

• a sour, bitter, or unusual taste in your mouth
• eye burning or stinging
• eye redness
• blurred vision
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for dorzolamide/timolol” section.

Serious side effects

Serious side effects of dorzolamide/timolol are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about dorzolamide/timolol’s side effects, refer to the prescribing information for dorzolamide/timolol listed in the “Resources” section.

With many drugs, serious side effects are possible but uncommon. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, dorzolamide/timolol’s serious side effects include:

• severe breathing problems
• heart failure
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for dorzolamide/timolol” section.

What to ask your doctor

Let your doctor know if you have questions about dorzolamide/timolol or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Should I continue using my other eye drops during treatment with dorzolamide/timolol?
• Should I administer another dose of dorzolamide/timolol if the drop runs out of my eye?
• Are there any tools I can safely use to help me administer eye drops?
• Is it safe for me to use dorzolamide/timolol if I have a sulfa allergy?

Resources

• Dorzolamide hydrochloride and timolol maleate — dorzolamide hydrochloride and timolol maleate solution/drops. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/efab039e-a69d-4306-8305-b1d27781cfe0/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks 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.