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Abstract #6466 Published in IGR 3-2
Efficacy of brimonidine 0.2% and dorzolamide 2% as adjunctive therapy to beta-blockers in adult patients with glaucoma or ocular hypertension
Simmons STClinical Therapeutics 2001; 23: 604-619
BACKGROUND: The alpha-adrenergic agonist brimonidine and the carbonic anhydrase inhibitor dorzolamide have been studied both as monotherapy and in combination with beta-blockers in the treatment of glaucoma and ocular hypertension; however, a Medline™ literature search failed to reveal any clinical studies directly comparing these two agents as adjunctive therapy. OBJECTIVE: The purpose of this study was to compare the intraocular pressure (IOP)-lowering efficacy of brimonidine and dorzolamide as adjunctive therapy to beta-blockers in adult patients with glaucoma or ocular hypertension. METHODS: In a prospective, investigator-masked, multicenter, parallel-design clinical trial, adult patients whose IOP was inadequately controlled with topical beta-blocker therapy were randomly assigned to receive brimonidine 0.2% twice daily or dorzolamide 2% 3 times daily as adjunctive therapy for three months. Efficacy was determined by the reduction in lap from baseline. After one month of adjunctive treatment, patients who failed to meet a target 15% reduction in lap at peak drug effect were crossed over to the other study medication. RESULTS: A total of 106 patients were treated. Approximately 70% (74/106) of the patients were white, and 61.3% (65/106) had a diagnosis of open-angle glaucoma. Mean baseline IOP (i.e., with beta-blocker monotherapy) was comparable between treatment groups ((similar to) 21 mmHg). After one month of adjunctive treatment, the mean daily IOP) reduction was significantly greater with brimonidine (4.40 mmHg, 20.4%) than with dorzolamide (3.0 mmHg, 14.4%; p = 0.033). At peak drug effect at one month, the mean lap reduction was significantly greater in the brimonidine group (5.95 mmHg, 27.6%) than in the dorzolamide group (4.11 mmHg, 19.7%; p = 0.007). Significantly more patients treated with brimonidine (44/51, 86.3%) than with dorzolamide (29/47, 61.7%) achieved the target 15% reduction in IOP at one month (p = 0.005). At three months, the mean daily IOP reduction and the mean IOP reduction at peak drug effect were not significantly different in the two treatment groups. The mean daily IOP reduction was 4.98 mmHg in the brimonidine group and 3.15 mmHg in the dorzolamide group (p = 0. 092). At peak drug effect, the mean IOP reduction was 6.39 mmHg with brimonidine and 4.06 mmHg with dorzolamide. The incidence of adverse events leading to discontinuation was 9.3% (5/54) in the brimonidine group (depression, two cases; allergic conjunctivitis, one; dry mouth and tearing, one; dermatitis, one) and 9.8% (5/51) in the dorzolamide group (ocular burning and stinging, two cases ocular itch, one; gastrointestinal complaints, one; lack of tolerance for beta-blocker, one), with no significant difference between the groups. CONCLUSIONS: In this trial, brimonidine 0.2% twice daily produced greater mean decreases in IOP and was effective in more patients than dorzolamide 2% three times daily when used as adjunctive therapy to beta-blockers.
Dr S.T. Simmons, Glaucoma Consultants Capital Reg., 1240 New Scotland Road, Slingerlands, NY 12159-9222, USA
Classification:
11.3.3 Apraclonidine, brimonidine (Part of: 11 Medical treatment > 11.3 Adrenergic drugs)
11.5.2 Topical (Part of: 11 Medical treatment > 11.5 Carbonic anhydrase inhibitors)
