Eyes Home > Side Effects of Dorzolamide/Timolol
Although most side effects of dorzolamide/timolol are often mild and easily treated (common reactions include redness, itching, or burning in the eye), there are some potentially serious reactions to be aware of. People with certain allergies or medical conditions may be more likely to experience side effects than others, so make sure your healthcare provider knows about all medical conditions you have when prescribing this drug.
An Introduction to Dorzolamide/Timolol Side EffectsJust like any medicine, dorzolamide/timolol (Cosopt®) can cause side effects. However, not everyone who uses the medication will have problems. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or are treated easily by you or your healthcare provider.
(This article covers many, but not all, of the possible dorzolamide/timolol side effects. Your healthcare provider can discuss a more complete list with you.)
Serious Side Effects of Dorzolamide/TimololSome dorzolamide/timolol side effects, while occurring infrequently, are potentially serious and should be reported immediately to your healthcare provider. Dorzolamide, one of the active ingredients, is a sulfonamide drug and therefore has the potential to cause severe allergic reactions. Be sure to let your healthcare provider know immediately if you develop any signs or symptoms of an allergic reaction, such as:
- An unexplained rash or hives
- Unexplained swelling, especially of the mouth, lips, or throat
- Wheezing or difficulty breathing.
Timolol, the other active ingredient, is a beta blocker that can cause serious, although rare, side effects, such as:
- A slow heart rate (bradycardia)
- Low blood pressure (hypotension)
- Worsening of asthma or chronic obstructive pulmonary disease (COPD)
- Heart attacks or strokes
- Signs of myasthenia gravis, such as muscle weakness, droopy eyelids, and double vision
- Signs of heart failure, such as:
- Water retention
- Swelling in the hands or feet
- Rapid weight gain (see Timolol and Weight Gain)
- Difficulty breathing
- Shortness of breath.
Of course, any eye drop can cause problems (such as an eye infection) if it is contaminated, so be sure to avoid touching the tip of the dropper to any surface, including the surface of the eye. Report any signs of an eye infection (such as severe pain, swelling, or redness) to your healthcare provider right away.