Abstract
Purpose: :
Compare the efficacy and tolerability of brimonidine tartrate–timolol maleate ophthalmic solution (Combigan®) with that of dorzolamide hydrochloride–timolol maleate ophthalmic solution (Cosopt®).
Methods: :
Single–center, investigator–masked, randomized, parallel–comparison of 40 patients. Enrolled patients were newly diagnosed or, in the opinion of the investigator, had IOP that was insufficiently controlled on a regimen of not more than 2 ocular hypotensive agents. If patients were using an ocular hypotensive lipid as 1 of those 2 medications, they continued on that lipid throughout the study and any other glaucoma medications were washed out. Patients were randomly assigned to instill either brimonidine/timolol or dorzolamide/timolol twice–daily for 3 months. Patients rated comfort, stinging, burning, and unusual taste on a scale of 1–5 (1–none and 5=severe). Study visits were at baseline, month 1 and month 3.
Results: :
In an interim analysis of 35 patients, patients reported that brimonidine/timolol was significantly more comfortable than dorzolamide/timolol (P=.004). Moreover, brimonidine/timolol patients reported significantly less burning (P<.001), stinging (P<.001), and unusual taste (P<.001) than dorzolamide/timolol patients. There was no significant difference in IOP at baseline (21.5 ± 4.7 mm Hg in brimonidine/timolol–treated patients and 21.3 ± 4.5 mm Hg in dorzolamide/timolol–treated patients, P=.897). The fixed combination of brimonidine/timolol provided statistically significant reductions in IOP at each follow–up visit (P<.001). Dorzolamide/timolol provided significant IOP–lowering at month 1 (P<.001) but not at month 3 (P=.067). At month 1, the mean IOP reduction in the brimonidine/timolol group was 5.4 ± 4.9 mm Hg (23.7%) compared with 4.4 ± 3.8 mm Hg (18.8%) in the dorzolamide/timolol group (P=.481). At the month 3 visit, brimonidine/timolol provided a mean IOP reduction of 5.6 ± 5.4 mm Hg (23.5%), compared with a mean IOP reduction of 2.9 ± 4.2 mm Hg (11.0%) provided by dorzolamide/timolol (P=.195). There were no statistically significant between–group differences in mean systolic or diastolic blood pressure (P>0.05) or heart rate (P>.423).
Conclusions: :
Brimonidine/timolol was significantly more comfortable and produced significantly less burning, stinging, and unusual taste than dorzolamide/timolol. Mean IOP–lowering was slightly greater with brimonidine/timolol than with dorzolamide/timolol.
Keywords: clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • intraocular pressure