SAN FRANCISCO, California — The first fixed-dose combination medication for glaucoma without a beta blocker lowers intraocular pressure by as much as 30%, results of a new clinical trial show.
The Alcon Laboratories combination, already under review by the US Food and Drug Administration, consists of brinzolamide 1% (Azopt) and brimonidine 0.2% (Alphagan).
This combination "could be important for patients with asthma and those with low pulse rates who can't take a beta blocker," said lead investigator Jess Whitson, MD, from the University of Texas Southwestern Medical Center in Dallas.
He presented the results here at the American Glaucoma Society 23rd Annual Meeting.
In this double-masked randomized study of 650 patients with open-angle glaucoma or ocular hypertension, investigators compared the efficacy and safety of the combination with each agent alone.
Patients attended a follow-up visit 2 weeks, 6 weeks, and 3 months after the initiation of treatment. During each clinic visit, the researchers checked intraocular pressure 4 times — at 8 AM, 10 AM, 3 PM, and 5 PM.
The investigators found that the combination was significantly more effective for lowering intraocular pressure than either of its constituent drugs alone (P ≤ .005).
Although all study participants experienced significant reductions in eye pressure at 3 months, those in the combination group benefited the most.
Table. Reduction in Intraocular Pressure at 3 Months
|Treatment||Baseline (%)||3 Months(%)|
Of the 143 patients who experienced at least 1 treatment-related adverse event, 26.2% were in the combination group, 18.8% were in the brinzolamide group, and 17.4% were in the brimonidine group.
The most common adverse effects in the combination group were eye irritation (5.4%), blurred vision (4.5%), and eye allergy (4.5%).
Fixed-dose combination glaucoma medications reduce exposure to preservatives, Dr. Whitson pointed out, and these are thought to produce adverse effects such as dry eye.
In addition to convenience, combination medications offer the advantage of a reduced risk for a washout effect, which is seen when 2 different medication drops are taken one after another, he added.
"This study shows us that the combination medication has an effect and that it's better than either of the agents taken alone," said Anne Coleman, MD, from the University of California at Los Angeles.
Yet she noted that it would have been helpful to know whether the combination medication is more effective than taking both medications individually.
"A combination medication does have the advantage of convenience. When patients have to put more than 1 set of drops into their eyes each day, compliance goes down," Dr. Coleman told Medscape Medical News.
She noted that because it doesn't contain a beta blocker, the combination drug might be a good alternative for some patients. Unlike medications with a beta blocker, these drops would not be expected to worsen asthma, induce an asthma attack, or exacerbate depression, she explained.
"The drops are absorbed into the body," she said, "so you have to consider their effect on the whole person systemically."
Dr. Whitson told Medscape Medical News he is not sure how long the regulatory process will take for this new agent.
Dr. Whitson reports being on the speaker's bureau for Alcon Laboratories, Allergan, and Merck. Dr. Coleman has disclosed no relevant financial relationships.
American Glaucoma Society (AGS) 23rd Annual Meeting: Abstract 91. Presented March 2, 2013.
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Cite this: New Glaucoma Drug Combo Lowers Eye Pressure - Medscape - Mar 22, 2013.