Key takeaways
Dorzolamide (Trusopt) and dorzolamide/timolol (Cosopt) are both medications used to treat high eye pressure in people with open-angle glaucoma or ocular hypertension but there are some differences. They both contain dorzolamide, a carbonic anhydrase inhibitor, which helps lower the amount of fluid in the eye. However, dorzolamide/timolol (Cosopt) also includes timolol, a beta blocker, which provides an additional mechanism to reduce eye pressure. Dorzolamide is typically used as a single medication and is applied as one drop in the affected eye(s) three times a day, while dorzolamide/timolol (Cosopt) is a combination medication used twice a day. Dorzolamide is only available as a generic, whereas dorzolamide/timolol (Cosopt) is available in both brand and generic forms, including a preservative-free option. Common side effects of both medications include burning or stinging in the eye, bluryr vision and bitter taste. Dorzolamide/timolol (Cosopt) may not be suitable for people with asthma or heart problems due to the presence of timolol, which can affect breathing and heart function.
