Cosopt: Agent for Glaucoma

If your doctor has diagnosed you with elevated intraocular pressure recently, you may be wondering how the pressure and pain can be decreased. There is a solution, which is a prescription medication known as Cosopt. Cosopt is also known as Dorzolamide Hydrochloride with Timolol Maleate.

Dorzolamide and Timolol are useful in the treatment of conditions where there is an excessive amount of aqueous humour in the eye causing increased pressure within the eye (raised intraocular pressure) in patients with open-angle glaucoma or ocular hyper-tension who are insufficiently responsive to beta-blockers. If you have been prescribed Cosopt, to use it, you must instill one drop of Cosopt in the affected eye(s) twice a day. If more than one topical ophthalmic drug is being used, the drugs need to be administered at least ten minutes apart. Before you instill, make sure you are in a lying down position with your head tilted backward. Look up at the ceiling, and hold the dropper above your eye. (Don't let the dropper touch your eye) Drop the Cosopt solution inside the lower lid, and then release the lid...keeping the eye open for at least thirty seconds. Then apply pressure to the inside corner of your eye for at least one minute.

How does Cosopt work? Well, Dorzolamide is part of a group of medicines known as carbonic anhydrase inhibitors. These medicines in Cosopt prevent the action of an enzyme in the body called carbonic anhydrase. Timolol belongs to the beta-blockers group. These medicines stop beta-receptors in the heart, lungs and other areas of the body. Carbonic anhydrase is typically responsible for the production of a salt (bicarbonate) in the human body. Bicarbonate is needed for the production of the watery liquid (aqueous humour) that fills the back of the eye. While Dorzolamide blocks the manufacturing of bicarbonate, it also ceases the production of aqueous humour. When Timolol is instilled as eye drops, it takes effect on receptors in the blood vessels of the eye and causes them to narrow (constrict). This decreases the amount of watery liquid (aqueous humour) which passes out of the blood vessels into the eyeball itself. Timolol also blocks the area of the eye which frequently fabricates aqueous humour.

It's best to avoid using Cosopt with other topical or systemic carbonic anahydrase inhibitors or beta-blocking agents. Additive effects may occur, and if you are a contact lens wearer, you may be negatively affected, so please consult your doctor if you are using contacts or using any other topical eye-related medicines. (Never instill Cosopt in your eyes when wearing your contact lenses! Remove them first! Lenses may be worn again fifteen minutes after instilling Cosopt.)

If you are a patient with a history of bronchia asthma, severe chronic obstructive pulmonary disease, sinus bradychardia, second or third degree atrioventricular block, overt cardiac failure, cardiogenic shock, or hyper-sensitive to beta-blockers or sulfonamides, be aware that using Cosopt may not be the best choice for you. If you notice any sign of cardiac failure, discontinue use right away. If you are using any beta-blockers at the moment, using Cosopt may increase the risk of general anesthesia, so temporarily stop using Cosopt before surgery. Signs of hypoglycemia may be lessened by using Cosopt. If you are a patient with diabetes mellitus and are taking insulin or oral hypoglycemic agents, use Cosopt with extreme caution. Also, be careful if you're a patient with hepatic or renal impairment (kidney failure). If you abruptly stop using beta-blockers, and you happen to have hyperthyroidism, thyrotoxicosos may occur. Thyrotoxicosos is when your thyroid gives you, and you may need to have your thyroids removed if this were to happen.

Now for the fun part: side effects. Inevitably, Cosopt may cause unwanted side effects, which include strange tastes in the mouth and burning in the eye. Some people also experience blurred vision, eye itching, and superficial punctuate keratitis (death of cells on surface of cornea).

With correct and regular use, your uncomfortable ocular symptoms should diminish. If you miss a dose, take it as soon as you remember, and keep Cosopt away from children.