Ocular Hypertension and Glaucoma
Brimonidine tartrate 0.15 and 0.2% ophthalmic solutions are used topically to reduce elevated intraocular pressure (IOP) in patients with open-angle glaucoma or ocular hypertension. Reduction in IOP may reduce or prevent glaucomatous visual field loss or optic nerve damage.
Controlled studies in patients with primary open-angle glaucoma or ocular hypertension have demonstrated that brimonidine tartrate 0.15% ophthalmic solution is therapeutically equivalent (i.e., in terms of the magnitude and duration of the hypotensive effect) to the 0.2% solution. In one 12-month clinical study, there were no substantial differences in IOP among patients treated with brimonidine tartrate 0.15 or 0.2% three times daily; the difference in mean IOP between the groups was less than 1 mm Hg at all evaluations during the 12-month period.
No clinical studies have been performed to date to compare the efficacy of brimonidine tartrate 0.15% with that of other ophthalmic drugs commonly used to reduce IOP in patients with open-angle glaucoma or ocular hypertension. However, in comparative clinical studies, efficacy of brimonidine tartrate 0.2% ophthalmic solution administered twice daily appeared to be similar to that of timolol 0.5% or betaxolol 0.25% administered twice daily.
During prolonged therapy with topical brimonidine tartrate 0.2%, the effect in reducing IOP generally was well maintained, but tolerance has been reported in some patients. (See Intraocular Pressure Monitoring under Warnings/Precautions: General Precautions, in Cautions.) The reduction in mean IOP has been maintained for up to 4 years after initial stabilization with the drug in some patients.
When used in conjunction with a topical β-adrenergic blocking agent (e.g., timolol), brimonidine may have an additive IOP-lowering effect. In clinical studies in patients receiving topical β-adrenergic blocking agents, the additive IOP-lowering effect of topical brimonidine tartrate 0.2% administered twice daily appeared to be comparable to that of topical pilocarpine hydrochloride 2% administered 3 times daily or topical apraclonidine 0.5% administered twice daily and more effective than topical dorzolamide 2% administered 3 times daily.