The dorzolamide/timolol combination versus timolol plus pilocarpine: patient preference and impact on daily life. United States Patient Preference Study Group. International Patient Preference Study Group.

PURPOSE: To compare the 2.0% dorzolamide/0.5% timolol fixed combination (COSOPT; Merck & Co., Whitehouse Station, NJ) to 0.5% timolol plus 2.0% pilocarpine given concomitantly, and to determine patient preference, tolerability, and impact on daily life in patients with elevated intraocular pressure (IOP).

METHODS: Two multi-center, randomized, cross-over, observer masked studies were conducted, one in the United States (97 patients) and one in Europe (93 patients). The Comparison of Ophthalmic Medications for Tolerability questionnaire was used to assess patient preference and perception of side effects and activity limitations resulting from study medications. Intraocular pressure was measured before and 2 hours after the morning dose of study medication (hour 0 and hour 2).

RESULTS: In both studies, among patients with a preference, the combination was preterred to timolol plus pilocarpine by a ratio of 4 to 1. The most commonly cited reason for this preference was side effects. Patients in both studies also reported that the combination interfered significantly less with daily life in terms of side effects and activity limitations. They also reported missing significantly fewer doses of study medication while taking the combination and being significantly more satisfied with it. The efficacy of these two treatments was not significantly different, based on IOP measurements at hour 0 and 2 hours after administration. Patients reported significantly more adverse events while receiving timolol plus pilocarpine in both studies, and in the U.S. study, significantly more patients discontinued therapy while receiving timolol plus pilocarpine than while receiving the combination.

CONCLUSION: Compared with timolol plus pilocarpine, patients preferred the combination of 2% dorzolamide/0.5% timolol, and reported less interference in daily activities, better tolerability, and better compliance with therapy.