This article is more than 5 years old. Information may no longer be current.
Brimonidine tartrate shows promise for treating glaucoma
Click Here to Manage Email Alerts
WAILEA, Hawaii—According to two researchers, an investigational drug may lower IOP by decreasing aqueous production and increasing uveoscleral outflow. Allergan Pharmaceuticals' brimonidine tartrate has been in clinical trials since the late 1980s and may be an alternative to the only currently available alpha-2 agonist, apraclonidine (Iopidine, Alcon).
"The advantage of this drug over apraclonidine is that it is more selective for the alpha-2 receptor," said Joel S. Schuman, MD, associate professor at Tufts University School of Medicine, director of glaucoma service at the New England Eye Center in Boston and principal investigator in Boston for many of the brimonidine studies.
Schuman also said brimonidine has fewer side effects than apraclonidine, specifically in terms of allergies. "With apraclonidine, there have been reports of early and late allergies, with rates running as high as 30% to 50%," he said. "With brimonidine, we are seeing about a 10% allergy rate in 1-year studies."
Brimonidine tartrate may also be applicable for chronic use. "In 1-year studies, there appears to be no tachyphylaxis," Schuman told his colleagues at the Hawaii '96 meeting, which was sponsored by the New England Eye Center, Tufts University School of Medicine and Ocular Surgery News.
Moreover, the drug appears to be an additive to miotics and carbonic anhydrase inhibitors.
Patient compliance is also enhanced because brimonidine can be administered twice a day compared with three times a day for apraclonidine.
According to Jorge A. Alvarado, MD, professor of ophthalmology at the University of California San Francisco, "This medication is unusual in that it is supposed to not only decrease aqueous humor production but also increase uveoscleral outflow. So it is working in both sites, and that may make it a potent new medication."
"It may be a good first- or second-line drug," Schuman added. Two 1-year studies comparing it to the gold-standard timolol found that brimonidine caused less burning and stinging: 24% vs. 41%.
However, "There were some alpha-agonist side effects such as dry mouth," Schuman said. "Dry mouth was somewhat more prevalent with the brimonidine than with timolol, 30% vs. 15%."
Supporting literature also notes that some patients complain of headaches, fatigue and drowsiness with the alpha-agonists. "In the studies, however, we found an equal incidence of headaches with brimonidine and timolol, about 19%," Schuman said. Fatigue and drowsiness rates were only slightly higher with brimonidine, 16% vs. 14%.
"Brimonidine is the second generation of alpha-2 agonists available for clinical use in eye care," Schuman said. "Like most second-generation compounds, brimonidine appears to have advantages over its predecessors."