Brimonidine-timolol reduces IOP more than dorzolamide-timolol

Curr Med Res Opin. 2009;25(7):1645-1653.

Fixed-combination brimonidine-timolol offered equal or greater IOP reduction compared with fixed-combination dorzolamide-timolol, a study showed.

"Both fixed-combination medications were safe and well-tolerated," the study authors said. "Brimonidine-timolol received higher ratings of ocular comfort than dorzolamide-timolol."

Investigators set out to assess the IOP-lowering potential and ocular tolerability of brimonidine-timolol and dorzolamide-timolol used alone or as an adjunct to a prostaglandin analogue in patients with glaucoma or ocular hypertension.

The study included data from two randomized, masked 3-month clinical trials conducted at 10 sites. Of 180 patients with open-angle glaucoma or ocular hypertension in need of IOP reduction, 101 patients received topical brimonidine-timolol twice daily as monotherapy or dorzolamide-timolol twice daily as monotherapy and 79 patients received fixed-combinations in conjunction with the prostaglandin analogues latanoprost, bimatoprost or travoprost.

Data showed no statistically significant differences in baseline IOP between the treatment groups. Investigators measured IOP at 10 a.m. at baseline, 1 month and 3 months.

At month 3, mean IOP reduction was 7.7 mm Hg (32.3%) among patients who received monotherapy brimonidine-timolol and 6.7 mm Hg (26.1%) among patients who received monotherapy dorzolamide-timolol (P = .040).

The mean reduction from baseline with prostaglandin analogues was 6.9 mm Hg among patients who received brimonidine-timolol and 5.2 mm Hg among those who received dorzolamide-timolol. The IOP reductions were 29.3% and 23.5%, respectively.

Further study is needed to compare the long-term efficacy and tolerability of the two fixed-combination therapies, the authors said.