Discontinuation rates of topical glaucoma medications in a managed care population

Background: Rates of medication discontinuation reflect factors including effectiveness, tolerability, cost, and dosing frequency. Discontinuation data can be useful to physicians and health plan managers as they compare various glaucoma medications. Objective: To compare rates of discontinuation of therapy in patients initially prescribed monotherapy with a topical glaucoma medication. Methods: Members of a managed care plan who filled at least 1 prescription for latanoprost, timolol, or brimonidine during a 30-month period were eligible to participate in this study. Prescription refill records for all glaucoma agents used in the plan were extracted for the study period. Rates of discontinuation of initial glaucoma therapy were compared using Cox regression methods; Kaplan-Meier survival curves were generated. Results: A total of 72,744 prescriptions were eligible, of which 48,491 were for study drugs. Latanoprost was the most frequently dispensed therapy (accounting for 49.7% of study drugs), followed by timolol (30.6%), and brimonidine (19.6%). After inclusion and exclusion criteria were applied, 2283 patients were included in analyses. Latanoprost-treated patients were significantly less likely to discontinue medication than were those treated with timolol or brimonidine. Kaplan-Meier survival curves confirmed that latanoprost-treated patients exhibited the greatest persistency with therapy. Conclusion: In this managed care setting, rates of discontinuation in patients initially treated with latanoprost were lower than those of patients receiving comparator drugs.