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Other drug names: A-Am An-Az B C-Ch Ci-Cz D-Dh Di-Dz E F G H I-J K-L M-Mh Mi-Mz N-Nh Ni-Nz O P-Pl Pm-Pz Q-R S-Sn So-Sz T-To Tp-Tz U-V W-Z 0-9   

Dorzolamide and Timolol (Ophthalmic)

Brand Names

In the U.S.-

  • Cosopt


  • Antiglaucoma agent, ophthalmic


Dorzolamide (dor-ZOLE-a-mide) and timolol ( TYE-moe-lole) combination medicine contains a carbonic anhydrase inhibitor (dorzolamide) and a beta-adrenergic blocking agent (timolol). It is used in the eye to treat increased pressure in the eye caused by open-angle glaucoma and a condition called hypertension of the eye.

This medicine is available only with your doctor's prescription, in the following dosage form:

  • Ophthalmic solution (eye drops) (U.S.)

Before Using This Medicine

In deciding to use a medicine, the risks of using the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For ophthalmic dorzolamide and timolol, the following should be considered:

Allergies- Tell your doctor if you have ever had any unusual or allergic reaction to carbonic anhydrase inhibitors (either ophthalmic or systemic), such as acetazolamide, brinzolamide, dichlorphenamide, dorzolamide, or methazolamide.

In addition, tell your doctor if you have ever had any unusual or allergic reaction to any of the beta-adrenergic blocking agents (either ophthalmic or systemic), such as acebutolol, atenolol, betaxolol, bisoprolol, carteolol, labetalol, levobunolol, metipranolol, metoprolol, nadolol, oxprenolol, penbutolol, pindolol, propranolol, sotalol, or timolol.

Also, tell your doctor if you have ever had any unusual or allergic reaction to sulfonamides (sulfa drugs) or thiazide diuretics (a type of water pill).

Furthermore, tell your health care professional if you are allergic to any other substances, such as benzalkonium chloride or other preservatives.

Pregnancy- This medicine has not been studied in pregnant women. However, studies in animals given very high doses of this medicine by mouth have shown that this medicine causes birth defects or other problems. Before using this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.

Breast-feeding- Although it is not known whether dorzolamide passes into the breast milk, timolol has been found to pass into the breast milk and it is possible that it could cause unwanted effects in nursing babies. Mothers who are using this medicine and who wish to breast-feed should discuss this with their doctor.

Children- Studies on this medicine have been done only in adult patients, and there is no specific information comparing use of this medicine in children with use in other age groups.

Older adults- Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of this medicine in the elderly with use in other age groups.

Other medicines- Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are using this medicine, it is especially important that your health care professional know if you are taking any of the following:

  • Beta-adrenergic blocking agents you take by mouth (acebutolol [e.g., Sectral], atenolol [e.g., Tenormin], betaxolol [e.g., Kerlone], bisoprolol [e.g., Zebeta], carteolol [e.g., Cartrol], labetalol [e.g., Normodyne], metoprolol [e.g., Lopressor], nadolol [e.g., Corgard], oxprenolol [e.g., Trasicor], penbutolol [e.g., Levatol], pindolol [e.g., Visken], propranolol [e.g., Inderal], sotalol [e.g., Sotacor], timolol [e.g., Blocadren])-The effects of both the timolol in the ophthalmic dorzolamide and timolol combination and the systemic beta-adrenergic blocking agents may be increased
  • Calcium channel blocking agents (bepridil [e.g, Vascar], diltiazem [e.g., Cardizem], felodipine [e.g., Plendil], flunarizine [e.g., Sibelium], isradipine [e.g., DynaCirc], nicardipine [e.g., Cardene], nifedipine [e.g., Procardia], nimodipine [e.g., Nimotop], verapamil [e.g., Calan] or
  • Digitalis glycosides (heart medicine) when used together with calcium channel blocking agents-Unwanted effects on the heart may be increased
  • Carbonic anhydrase inhibitor****“type glaucoma medicine you take by mouth (for example, acetazolamide [e.g., Diamox], dichlorphenamide [e.g., Daranide], or methazolamide [e.g., Neptazane])-Effects of these medicines on the body may be increased
  • Quinidine (e.g., Cardioquin) or
  • Reserpine (e.g., Serpasil) and other catecholamine-depleting medicines-Effects of the ophthalmic dorzolamide and timolol combination may be increased, possibly leading to slow heartbeat, low blood pressure, and fainting

Other medical problems- The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
  • Allergy, history of-Severity and duration of allergic reactions to other substances may be increased
  • Asthma or
  • Bronchitis or
  • Emphysema or
  • Lung problems, other-This medicine can increase trouble in breathing
  • Bradycardia (unusually slow heartbeat) or
  • Heart problems, other-There is a risk of further decreased heart function
  • Diabetes mellitus (sugar diabetes) or
  • Hypoglycemia-If your blood sugar becomes too low, this medicine may cover up some of the symptoms
  • Kidney disease, severe-Effects of this medicine may be increased because of its slower removal from the body
  • Myasthenia gravis-This medicine may make this condition worse
  • Overactive thyroid-This medicine may cover up fast heartbeat, which is a sign of overactive thyroid

Proper Use of This Medicine

To use:

  • The bottle is only partially full to provide proper drop control.
  • First, wash your hands. Tilt the head back and, pressing your finger gently on the skin just beneath the lower eyelid, pull the lower eyelid away from the eye to make a space. Drop the medicine into this space. Let go of the eyelid and gently close the eyes. Do not blink. Keep the eyes closed and apply pressure to the inner corner of the eye with your finger for 1 or 2 minutes to allow the medicine to be absorbed by the eye.
  • Immediately after using the eye drops, wash your hands to remove any medicine that may be on them.
  • To keep the medicine as germ-free as possible, do not touch the applicator tip to any surface (including the eye) . Also, keep the container tightly closed. Serious damage to the eye and possible loss of vision may result from using contaminated eye drops.

Use this medicine only as directed by your doctor . Do not use more of it and do not use it more often than your doctor ordered. To do so may increase the chance of too much medicine being absorbed into the body and the chance of side effects.

If your doctor ordered two different eye drops to be used together, wait at least 10 minutes between the times you apply the medicines. This will help to keep the second medicine from ****œwashing out" the first one.


The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

  • For ophthalmic dosage form (eye drops):
    • For glaucoma or hypertension of the eye:
      • Adults-Use 1 drop of the medicine in the affected eye(s) two times a day.
      • Children-Use and dose must be determined by your doctor.

Missed dose-

If you miss a dose of this medicine, use it as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


To store this medicine:

  • Keep out of the reach of children.
  • Store away from heat and direct light.
  • Keep the medicine from freezing.
  • Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

It is important that your doctor check your progress at regular visits to make sure that this medicine is working properly and is not causing unwanted effects.

If itching, redness, swelling, or other signs of eye or eyelid irritation occur, stop using this medicine and check with your doctor . These signs may mean that you are allergic to this medicine.

Before you have any kind of surgery, dental treatment, or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine . This medicine contains an ophthalmic beta-adrenergic blocking agent. Using an ophthalmic beta-adrenergic blocking agent during this time may cause an increased risk of side effects.

It is very important that you check with your doctor if you get an injury or infection in your eye or if you are scheduled to have eye surgery. Your doctor will tell you whether to keep using the same container of eye drops or whether you should start using a fresh bottle of eye drops.

For diabetic patients :

  • This medicine may cover up some signs of hypoglycemia (low blood sugar) . If you notice a change in the results of your blood or urine sugar tests or if you have any questions, check with your doctor.

This medicine contains benzalkonium chloride, which may be absorbed by contact lenses. Take soft contact lenses out before using this medicine. Lenses may be put back in 15 minutes after using the medicine.

Side Effects of This Medicine

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

  • More common
    • Blurred vision;  feeling of something in eye;  itching of the eye;  redness of eye and lining of eyelid;  sensitivity of eyes to light 

  • Less common
    • Back, abdominal, or stomach pain;  change in vision;  coughing, shortness of breath, troubled breathing, tightness in chest, or wheezing;  discharge from eye;  dizziness;  eye or eyelid pain, swelling, discomfort, or irritation;  increased blood pressure;  increased frequency of urination or painful urination;  itching of eyelid ;  seeing flashes or sparks of light;  seeing floating spots before the eyes;  swelling of lining of eyelid;  tiny bumps on lining of eyelid 

  • Rare
    • Blood in urine;  chest pain;  diarrhea;  lightheadedness or fainting ;  headache or weakness, severe and sudden;  mental depression;  nausea or vomiting ;  pain, numbness, tingling, or burning feeling in hands or feet;  skin rash;  slow heartbeat;  unusual tiredness or weakness 

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

  • More common
    • Bitter, sour, or unusual taste;  burning or stinging of the eye (when medicine is applied) 

  • Less common
    • Cold- or flu-like symptoms;  crusting or scales on eyelid;  dryness of eyes;  headache;  indigestion or upset stomach ;  sore throat;  stuffy or runny nose;  tearing of eye 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

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Last updated: Tue, 06 Jan 2009 00:20:03 GMT