Precautions and Warnings With Dorzolamide/Timolol
Dorzolamide/timolol could react negatively with epinephrine; therefore, people with a history of severe allergic reactions, who often need to use epinephrine to treat such problems, may not be able to use this eye drop. Precautions and warnings with dorzolamide/timolol also apply to women who are pregnant or breastfeeding, as well as people with certain conditions affecting the heart, lungs, liver, or kidneys.
What Should I Tell My Healthcare Provider?You should talk with your healthcare provider prior to using dorzolamide/timolol (Cosopt®) if you have:
- Liver disease, such as liver failure, cirrhosis, or hepatitis
- Kidney disease, such as kidney failure (renal failure)
- Chronic obstructive pulmonary disease (COPD)
- Myasthenia gravis
- Heart failure
- Had a recent heart attack
- A slow heart rate (bradycardia)
- Heart block
- An upcoming surgery
- Any allergies, including to food, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant
Make sure to tell your healthcare provider about any other medications you are taking, including prescription and nonprescription medicines, vitamins, and herbal supplements.
Specific Dorzolamide/Timolol Precautions and WarningsWarnings and precautions to be aware of prior to using this product include the following:
- Dorzolamide/timolol contains a sulfonamide ("sulfa" drug) and can cause serious reactions in people allergic to such medications.
- Even though dorzolamide/timolol is an eye drop, a significant amount of the medication may be absorbed into the bloodstream. Therefore, most of the usual warnings and precautions with other carbonic anhydrase inhibitors or beta blockers also apply to dorzolamide/timolol.
- This medication may worsen allergic reactions and may make epinephrine (one of the standard treatments for life-threatening allergic reactions) less effective. If you have a history of severe allergic reactions, this product may not be the best choice for you.
- Like all beta blockers, dorzolamide/timolol can worsen heart failure in some situations. If you have congestive heart failure, your healthcare provider may need to monitor you very closely while you use dorzolamide/timolol. Let your healthcare provider know immediately if your heart failure symptoms seem to become worse.
- Beta blockers can worsen breathing problems like asthma or COPD. In many cases, dorzolamide/timolol is not recommended for people with such lung problems.
- This medication may worsen myasthenia gravis symptoms or may even cause this condition. Let your healthcare provider know if you develop symptoms of this problem, such as muscle weakness, double vision, or a droopy eyelid.
- If you will be having surgery, make sure your surgeon and anesthesiologist know you take dorzolamide/timolol, as it may affect the choice of medications used during the surgery.
- Beta blockers can mask some of the symptoms of low blood sugar (hypoglycemia), particularly the "racing heart" feeling. This can cause serious problems for people with diabetes, who need to be able to sense that they have low blood sugar in order to correct it before it becomes life-threatening. Some beta blockers may also worsen low blood sugar, although it is not known if this is a concern with dorzolamide/timolol.
- Beta blockers can mask some of the symptoms of an overactive thyroid (hyperthyroidism).
- Dorzolamide/timolol can potentially interact with a number of other medications (see Drug Interactions With Dorzolamide/Timolol).
- This product has not been adequately studied in people with liver or kidney problems. Dorzolamide/timolol is not recommended for people with severe kidney problems and should be used with caution in people with liver problems.
- If you wear soft contact lenses, be sure to remove them before each dorzolamide/timolol dosage and wait at least 15 minutes before reinserting them. Dorzolamide/timolol contains a preservative (benzalkonium chloride) that can bind to soft contact lenses.
- If you will be having eye surgery or develop any other eye problems or conditions (such as an infection), check with your healthcare provider about whether you should continue to use this medication.
- If you use other eye drops, be sure to separate your dose of dorzolamide/timolol from that of the other drops by at least 10 minutes.
- Dorzolamide/timolol is considered a pregnancy Category C medication. This means that it may not be safe for use during pregnancy, although the full risks are not currently known (see Cosopt and Pregnancy).
- At least one of the active ingredients in this product passes through breast milk. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Cosopt and Breastfeeding).