Objective: To compare the safety and intraocular pressure (IOP)-lowering effects of brimonidine-purite 0.1% with the marketed formulation of brimonidine-purite 0.15% (Alphagan P 0.15%) when used twice daily (BID) by patients with glaucoma or ocular hypertension previously treated with brimonidine-purite 0.15% for at least 6 weeks.
Methods: In a 12-month, randomized, double-masked, multicenter, parallel group, non-inferiority study, patients with glaucoma or ocular hypertension who were treated with brimonidine-purite 0.15% BID were randomly assigned to continue brimonidine-purite 0.15% (n=102) or to administer brimonidine-purite 0.1% (n=105) BID for 12 months. IOP was measured at approximately 8 a.m. (hour 0) and 10 a.m. (hour 2).
Main outcome measures: Mean change from baseline IOP and adverse events.
Results: Demographics and baseline characteristics were similar between treatment groups. Treated-baseline mean IOPs at both timepoints were similar between groups (p > or = 0.606). Brimonidine-purite 0.1% provided IOP-lowering that was non-inferior to brimonidine-purite 0.15% at each of the 12 follow-up timepoints, and there were no statistically significant between-group differences at any timepoint. The most commonly reported adverse event was conjunctival hyperemia (13.5% for brimonidine-purite 0.1%; 10.8% for brimonidine-purite 0.15%). No significant differences in the incidence of adverse events were noted between the two formulations.
Conclusions: Brimonidine-purite 0.1% BID is as effective as brimonidine-purite 0.15% BID in lowering IOP in patients with glaucoma or ocular hypertension who were previously treated with brimonidine-purite 0.15%, and both formulations are well tolerated. Limitations of the study include enrollment of only patients who were already on treatment with brimonidine-purite 0.15%. The 0.1% formulation of brimonidine-purite allows for decreased exposure to brimonidine while providing an IOP-lowering effect comparable to that of the 0.15% formulation. Clinical trial registered at clinicaltrials.gov; identifier: NCT00168363.