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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: dorzolamide (dor ZOLE a mide)
Brand name(s): TRUSOPT
GENERIC: not available FAMILY: Drugs for Glaucoma
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: dorzolamide and timolol (dor ZOLE a mide and TIM oh lole)
Brand name(s): COSOPT
GENERIC: not available FAMILY: Drugs for Glaucoma
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

These drugs caused fetal harm in animal studies, including malformation of the spine and delayed bone formation. Use during pregnancy only for clear medical reasons. Tell your doctor if you are pregnant or thinking of becoming pregnant before you take this drug.

Breast-feeding Warning

These drugs are excreted in human milk and caused delays in development of pups in animal studies. Because of the potential for serious adverse effects in nursing infants, you should not take these drugs while nursing.

Facts About This Drug [top]

Dorzolamide (TRUSOPT) is used to treat glaucoma, especially open-angle glaucoma, and to lower pressure in the eye. This medication is also used in certain eye surgeries. Excess pressure in the eye can damage the optic nerve and cause loss of vision. Dorzolamide blocks the enzyme carbonic anhydrase, as does the oral drug acetazolamide (DIAMOX). Carbonic anhydrase is present in the eyes, kidney, lungs and stomach. Dorzolamide belongs to the family of sulfa drugs.

The usual dose of...

Dorzolamide (TRUSOPT) is used to treat glaucoma, especially open-angle glaucoma, and to lower pressure in the eye. This medication is also used in certain eye surgeries. Excess pressure in the eye can damage the optic nerve and cause loss of vision. Dorzolamide blocks the enzyme carbonic anhydrase, as does the oral drug acetazolamide (DIAMOX). Carbonic anhydrase is present in the eyes, kidney, lungs and stomach. Dorzolamide belongs to the family of sulfa drugs.

The usual dose of dorzolamide is one drop in the affected eye or eyes, three times daily. Some people may be able to use the drug twice daily.[1] Drugs for glaucoma usually work more quickly in people with light-colored eyes than in people with dark eyes.[1] Bitter taste is a common adverse effect to dorzolamide. If the container becomes contaminated, your eye can be damaged, or you may even suffer loss of vision. Dorzolamide does not lower pressure in the eye as much as acetazolamide or timolol.[2],[3] Adverse effects are generally less likely than with oral acetazolamide. However, dorzolamide, like other eye drops, is absorbed throughout your body. Any adverse effect of sulfas or carbonic anhydrase inhibitors could occur with dorzolamide. These include rare but sometimes fatal severe allergic reactions, blood disorders and bone marrow depression.

People who are allergic to sulfa drugs should not use dorzolamide. Dorzolamide has not been studied in people with liver problems. It is not recommended for people with narrow-angle glaucoma, kidney disease, or people who wear soft contacts. Dorzolamide is also not recommended for women who are pregnant or nursing. Information about dorzolamide, particularly effects after use for more than one year, remains limited. If you stop taking dorzolamide, some of the drug may remain in your body for a few months.[1]

Timolol has two forms for different uses: BLOCADREN tablets for the heart and TIMOPTIC eye drops for the eyes, specifically for treating glaucoma.

The dorzolamide and timolol combination (COSOPT) is a product used to lower pressure in the eye when treatment with a single anti-glaucoma drug has failed to accomplish this objective.[4],[5] This combination drug is as effective as applying each drug separately; however, it costs more than buying them individually. Additionally, this combination choice is far from ideal. Studies comparing brimonidine (ALPHAGAN) and dorzolamide for use as combination drugs with timolol found that brimonidine is a significantly more effective second agent than dorzolamide for further lowering eye pressure in timolol users.[6],[7]

In June 2010, the FDA issued labeling changes to the product package inserts of dorzolamide and dorzolamide with timolol highlighting safety information. The changes state that topical dorzolamide is absorbed systemically (in the body), and adverse effects, including severe skin reactions, can occur with the topical administration.[8]

The following is true for dorzolamide alone. See analogous information for timolol.

Before You Use This Drug [top]

Do not use if you have or have had:

  • allergy to dorzolamide

Tell your doctor if you have or have had:

  • pregnancy or are breast-feeding[1]
  • liver disorder
  • kidney disorder

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

The following is true for dorzolamide alone. See analogous information for timolol.

When You Use This Drug [top]

  • If using more than one eye drug: Wait 10 minutes between the use of two different eye preparations to prevent “washing out” of the first one.
  • Be careful, since blurred vision can occur temporarily. Check with your doctor if blurred vision continues.
  • Check with your doctor if you have itching, redness, or swelling of eye or eyelid.
  • Eyes can be sensitive to sunlight or bright light; wear sunglasses and avoid exposure to bright light.

The following is true for dorzolamide alone. See analogous information for timolol.

How to Use This Drug [top]

  • Prevent the container from becoming contaminated. Avoid letting the tip of the container touch your eye, hands, or any other object.
  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

The following is true for dorzolamide alone. See analogous information for timolol.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

acetazolamide, DIAMOX, dichlorphenamide, methazolamide, quinidine, TOPAMAX, topiramate.

For dorzolamide with timolol, the preceding apply, plus arbutamide, DELTASONE, prednisone.

Other possible drug interactions are: cholinesterase inhibitors, such as ambenonium (MYTELASE), edrophonium (TENSILON), neostigmine (PROSTIGMIN), or pyridostigmine (MESTINON). The effect of these drugs (often used in myasthenia gravis) may be lowered by dorzolamide.[1] When taken with diuretics there can be a greater loss of potassium.[1] Use with phenytoin (DILANTIN) may aggravate osteoporosis.[1] Salicylic acid (SALSALATE) taken with dorzolamide can lead to acidosis.[1] Also, the preservative in dorzolamide drops (benzalkonium chloride) can interact with soft contact lenses.

The following is true for dorzolamide alone. See analogous information for timolol.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • blood in urine
  • eye pain, tearing, and blurred vision
  • itching, redness, swelling, or other signs of eye or eyelid irritation
  • nausea or vomiting
  • pain in side, back, or abdomen
  • skin rash

Call your doctor if these symptoms continue:

  • bitter or metallic taste
  • blurred vision
  • burning, stinging, or discomfort when medicine is applied
  • dryness of eyes
  • feeling of something in eye
  • headache
  • nausea
  • sensitivity of eyes to light
  • tearing of eye
  • unusual tiredness or weakness

last reviewed January 31, 2021