An Open Label Prospective Randomized Trial to Compare The Efficacy Tolerability and Cost Effectiveness of Brand Name Versus Two Different Generic Drug of Fixed Combination Dorzolamide 2% and Timolol 0.5% in The Treatment of Primary Open Angle Glaucoma

Abstract

Purpose: To compare the efficacy tolerability and cost effectiveness of brand name versus two different generic drug of fixed combination dorzolamide 2% and timolol 0.5% in the treatment of primary open angle glaucoma.Methods: Sixty-six eyes of 66 patients with newly diagnosed, open-angle glaucoma were included in this prospective, examiner masked, randomized study. All patients underwent routine ophthalmic examinations at baseline and 6 months of treatment. After initial examination, patients were randomly divided into three groups and prescribed to use fixed combination treatment of dorzolamide/timolol (D/T) brand name and two different generic name drops. Retrobulbar blood flow was assessed with color Doppler imaging (CDI). At end-of-treatment assessments, patients were requested to fill in a questionnaire based on "the Comparison of Ophthalmic Medications for Tolerability".Results: Intraocular pressure (IOP) and CDI measurements were similar at baseline. Compared to baseline, the brand name drop had a better resistive index lowering effect than two other generic drugs, however the difference was not statistically significant (p=0.056). Brand name D/T fixed combination provided greater significant mean IOP reductions from baseline than two other generic name drops (p=0.001). There were no statistically significant differences in the IOP lowering effect between generic drops (p=0.562). Tolerability was similar between groups. Generic bottles failed to last a month for 80% patients. Conclusions: Brand name product of D/T fixed combination is exactly more effective in IOP reduction and seems to be having a better lowering effect on resistive index, even a statistically significant result was not found.