2 Drugs Used To Treat Glaucoma

Epinephrine & Apraclonidine

Epinephrine: Epinephrine is an agonist drug used to control glaucoma. Some of the brand names it is sold under include Epifrin, Epinal, Epitrate, Eppy, and Glaucon. It is a nonselective medication because it acts on more than one area in the eye; it affects aqueous flow, trabecular outflow, and uveascleral outflow. Chemically, epinephrine is identical to the hormone adrenaline, which is secreted by the adrenal gland and is known to control glaucoma. Secretions of this fluid are extremely complex, and the mystery of its manufacture and diffusion still remain to be unraveled.

Epinephrine medications work well at reducing IOP, but may create one or two problems. After a period of use, or at times immediately after you instill the drop, your eye may become red. This is because epinephrine dilates the blood vessels in the eye. The redness is harmless, but most people object to walking around with a red eye. If your eye begins to itch and/or hurt, you may be having an allergic reaction to the medication.

Scientists have found that if epinephrine is combined with another drug, dipivefrin, better results can be obtained. This combination is sold under the brand name Propine. Because Propine penetrates the cornea and reaches the interior of the eye more rapidly, some of the troublesome effects of epinephrine are averted. But not for long. The body catches on and the reactions against the drug begin to reappear. Unlike the miotics, Propine dilates the pupil, which helps to counteract somewhat the pupil-constricting properties of the miotics such as pilocarpine and carbachol. It also constricts the blood vessels on the surface of the eye, which enhances the whiteness of your sclera, giving your eye a beautiful appearance.

Epinephrine can cause blurred vision if you wear soft contact lenses, because it stains the lenses. Propine is said to avert this problem, possibly because of its rapid penetration into the eye. People with heart problems and/or high blood pressure should use any drugs in the epinephrine family with caution, for systemic side effects can include acute hypertension (high blood pressure), arrhythmia (irregular heartbeat), and angina (chest pains). If you already have any of these problems, the drug can worsen them.

Apraclonidine: Apraclonidine (lopidine) is another agonist drug used in the treatment of glaucoma. The mechanism of how it works is not completely established, but researchers believe it predominantly reduces the formation of aqueous humor. Originally, apraclonidine was used to counteract the temporary spikes in IOP that can occur directly following laser treatment. Heartened by its effect on intraocular pressure, ophthalmologists lobbied the U.S. Food and Drug Administration (FDA) to approve its use in the general treatment of glaucoma, and 1995, apraclonidine joined the list of medications prescribed for lowering IOP.

As with any medication, there can be side effects. Possible side effects of apraclonidine include dilation of the pupil, burning, discomfort, a foreign-body sensation, dryness, itching, blurred or dimmed vision, a generalized allergic response, and tiny hemorrhages in the conjunctiva.

Systemically, it can cause abdominal pain, diarrhea, stomach discomfort, and vomiting. People with some forms of severe cardiovascular disease are advised against taking this medication because it lowers blood pressure. Some patients have complained of insomnia, dream disturbances, irritability, and decreased libido. Others have cited dry mouth, nasal burning or dryness, headache, heaviness or burning in the chest, clammy or sweaty palms, body heat, shortness of breath, fatigue, and pain in the extremities. In some patients, this drug apparently loses its effectiveness after several months' use.