Glaucoma Medicines Available In Combination Form
Leading Glaucoma Medicines Now Available In Combination Form To Help Preserve Eyesight
COSOPT® (dorzolamide hydrochloride - timolol maleate ophthalmic solution), the first eyedrop that combines two leading glaucoma medications to dramatically reduce the fluid pressure within the eye known as intraocular pressure (IOP), will become available in New Zealand from 1 April 2002. Physicians worldwide have already prescribed more than 11.7 million patient months of therapy with COSOPT.
In an agreement announced today by PHARMAC, COSOPT will be fully subsidised for patients from 1 April 2002. On the same date, access to a currently listed Merck Sharp & Dohme (MSD) product TRUSOPT® (dorzolamide ophthalmic solution) will be widened and two other MSD ophthalmic medicines, TIMPILO® (timolol maleate) and TIMOPTOL-XE® (timolol maleate gel-forming eye drops) will also move from being part-funded to being fully-funded by PHARMAC.
Glaucoma is a leading cause of blindness around the world. Patients with glaucoma usually have elevated IOP, which can damage the optic nerve and cause loss of vision.
COSOPT is indicated for the treatment of elevated IOP in patients with ocular hypertension, open-angle glaucoma, pseudoexfoliative glaucoma, or other secondary open angle glaucomas when concomitant therapy is appropriate. Primary open angle glaucoma is the most common type of glaucoma and results when an unexplained buildup of aqueous humor (the clear fluid in the eye) causes increased IOP.
ophthalmic solution is a combination of dorzolamide
hydrochloride 2% (TRUSOPT®), a topical carbonic anhydrase
inhibitor, and timolol maleate 0.5% (TIMOPTOL ®), an
ophthalmic beta blocker -- both components reduce the
buildup of aqueous humor. “After administering COSOPT, we
saw a dramatic reduction in IOP,” said Alain Bron, MD, Head
of the Department of Ophthalmology, University Hospital,
Dijon, France. Dr. Bron added that, “we saw this result
without an increase in side effects.”
Studies show superior results over monotherapy
Clinical studies provide strong evidence of the IOP lowering effects of COSOPT. In one clinical trial, 335 patients with increased IOP in both eyes received either COSOPT or one of its components. After three months of therapy, the average IOP measured two hours after treatment was nearly 33 percent lower for patients on COSOPT, compared to 20 percent lower for patients on dorzolamide and 23 percent lower for patients taking timolol. The IOP lowering effect of COSOPT was statistically significantly greater (p<0.001) than that of either of its two components. Furthermore, the study found that COSOPT was well tolerated.
“Combination therapies may provide important benefits for patients, particularly for the many elderly glaucoma patients,” said Ingrid Adamsons, MD, Director Clinical Research, Ophthalmology. at Merck Research Laboratories. “Patient confusion may be reduced when one eyedropper takes the place of two. It also eliminates the chance of washing out the first drop when the second medication is applied.”
directions in glaucoma treatment
New research increasingly suggests that factors independent of IOP may contribute to progressive vision loss. Clinical studies are now underway, investigating reduced blood flow in the retina and optic nerve as possible contributors to glaucoma.
Based on these investigations, reducing IOP and enhancing ocular blood flow may prove effective as a dual means for controlling glaucoma. Preliminary studies indicate that COSOPT may enhance blood flow. Dorzolamide is a selective inhibitor of carbonic anyhdrase isoenzyme II and may promote blood vessel dilation, thereby increasing the blood supply to the eye.
Glaucoma: a major cause of blindness
Open angle glaucoma affects approximately one to more than three percent of the elderly population aged 55 years and older according to large population studies in England, Wales and the Netherlands. Statistics in the United States show that open angle glaucoma is a leading cause of blindness, with one million people unaware of their condition. Although primary open angle glaucoma has no known cause, individuals at risk for glaucoma include those older than age 60, people of African descent, those with diabetes, and those who have a family history of the condition.
Important new dispenser for accurate
In response to the need for improved delivery of eyedrops, COSOPT and TRUSOPT will be available in a new dispenser, the OCUMETER PLUS. The larger bottle is designed for ease of handling and precision control for single-drop dosing.
COSOPT was first made available in 1998, and is currently available in 61 countries worldwide. COSOPT is a product of Merck Sharp & Dohme (MSD). The medicine is contraindicated in patients with bronchial asthma or a history of bronchial asthma, or severe chronic obstructive pulmonary disease; sinus bradycardia, second or thrid degree atrioventricular block, overt cardiac failure, cardiogenic shock; hypersensitvity to any component of this product.
During clinical studies, the most frequently reported adverse events associated with the use of COSOPT were burning and/or stinging of the eyes and changes in taste. Approximately 2.4 percent of patients discontinued therapy as a result of adverse events.
Merck Sharp & Dohme
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