A multicenter study comparing dorzolamide and pilocarpine as adjunctive therapy to timolol: patient preference and impact on daily life.

Background: A multicenter, 4-week, two-period crossover study, comparing 2% dorzolamide three times daily to 2% pilocarpine four times daily as adjunctive therapy to 0.5% timolol twice daily, was conducted on 81 patients with elevated intraocular pressure (IOP). The treatments were evaluated for patient preference, tolerability, impact on daily life, IOP control, and visual-field changes.

Methods: The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference, as well as the perception of side effects and activity limitations resulting from the study medications. IOP measurements and visual-field examinations were obtained at baseline and at the end of each crossover period.

Results: Of the 77 patients who participated in both periods, 63 (82%) preferred dorzolamide. Patients who expressed a preference preferred dorzolamide over pilocarpine by a ratio of more than 10:1. Patients reported less interference with their daily life because of side effects and activity limitations while receiving dorzolamide than while receiving pilocarpine. Dorzolamide and pilocarpine were comparably effective in lowering IOP (16% to 17%). Also, significantly more patients reported adverse experiences and discontinued therapy as a result of adverse experiences while receiving pilocarpine than while receiving dorzolamide.

Conclusion: The results of this multicenter study support those of two previous single-center studies; these results show that dorzolamide was greatly preferred over pilocarpine and had better tolerability and less adverse impact on patients' daily lives than pilocarpine.