Comparison of the efficacy and tolerability of preservative-free and preservative-containing formulations of the dorzolamide/timolol fixed combination (COSOPT™) in patients with elevated intraocular pressure in a randomized clinical trial.

BACKGROUND: The aim of this study was to compare the efficacy and tolerability of preservative-free (PF) and preservative-containing (PC) formulations of the dorzolamide/timolol fixed combination (COSOPT™) in patients with elevated intraocular pressure (IOP). METHODS: A parallel, randomized, double-masked study was conducted. After a 3-week run-in on timolol, patients with ocular hypertension, as confirmed by an IOP ≥22 mmHg, were randomized 1:1 to receive PF or PC dorzolamide/timolol twice daily for 12 weeks. IOP was measured at hour 0 (drug trough) and hour 2 (drug peak) at baseline (last day of 3-week timolol run-in), and weeks 2, 6 and 12. RESULTS: A total of 261 patients were randomized. Mean baseline IOPs were 23.7 mmHg for both treatments at hour 0 and 21.2 mmHg for PF dorzolamide/timolol and 21.4 mmHg for PC dorzolamide/timolol at hour 2. At all study time points (trough and peak at weeks 2, 6, and 12), the difference between treatments in mean change from baseline IOP was <0.5 mmHg. The 95% confidence intervals for the estimated treatment difference (PF minus PC) in mean change from baseline IOP at week 12 was -0.86 to 0.23 mmHg for trough (primary endpoint) and -0.39 to 0.67 mmHg for peak (secondary endpoint). The most common adverse events were ocular burning/stinging, reported by 16.0% and 21.5% of patients receiving PF and PC dorzolamide/timolol respectively, and taste perversion, reported by 3.1% and 5.4% of patients receiving PF and PC dorzolamide/timolol respectively. CONCLUSIONS: In patients with elevated IOP, PF and PC dorzolamide/timolol were equivalent in efficacy for change in trough and peak IOP, and had generally similar tolerability.

A randomized trial assessing dorzolamide in patients with glaucoma who are younger than 6 years.

OBJECTIVE: To evaluate dorzolamide hydrochloride in patients younger than 6 years who have an elevated intraocular pressure or glaucoma. DESIGN: A 3-month, controlled, randomized, double-masked, multicenter, clinical trial. Patients were randomized to 2% dorzolamide 3 times daily or timolol maleate gel-forming solution (0.25% for patients <2 years and 0.5% for patients > or =2 but <6 years) once daily plus placebo twice daily. If the intraocular pressure was not controlled through monotherapy, younger patients received concomitant dorzolamide 3 times daily and 0.25% timolol gel-forming solution once daily and older patients received a fixed combination of 2% dorzolamide and 0.5% timolol twice daily. The primary safety variable was the proportion of patients who discontinued therapy for a drug-related adverse experience. Intraocular pressure reduction was a secondary measure. RESULTS: One younger patient (1.8%) of 56 randomized to dorzolamide discontinued concomitant therapy because of bradycardia. Two older patients (3.0%) of 66 discontinued dorzolamide because of ocular adverse experiences. The most frequent ocular adverse experiences were discharge and ocular hyperemia (younger cohort) and ocular hyperemia and burning/stinging (older cohort). At week 12, the mean change in intraocular pressure for dorzolamide was statistically significant from baseline (-7.3 mm Hg [-20.6%] and -7.1 mm Hg [-23.3%]) in the younger and older cohorts, respectively; P<.001 for both. CONCLUSION: Dorzolamide was generally well tolerated and demonstrated efficacy for up to 3 months in patients younger than 6 years.

Efficacy of the dorzolamide/timolol fixed combination versus latanoprost in the treatment of ocular hypertension or glaucoma: combined analysis of pooled data from two large randomized observer and patient-masked studies.

In previous analyses of primary efficacy data from two randomized clinical trials, standard dosing regimens of the dorzolamide/timolol fixed combination (COSOPT) and latanoprost (XALATAN) were shown to have equivalent efficacy with regard to reduction in mean daytime diurnal intraocular pressure (IOP). We performed additional post hoc analyses of pooled data from these studies to compare further the efficacy of the two treatments. The studies used identical 3-month, parallel group, randomized, observer-masked and patient-masked, multicenter designs. Patients with a baseline IOP > or = 24 mm Hg were randomized to either the 2% dorzolamide/0.5% timolol combination eye drops twice daily (n = 273) or 0.005% latanoprost eye drops once daily (n = 271). The IOP measurements were made at 8 AM, 10 AM, 2 PM, and 4 PM at the baseline visit and then on each of the 3 monthly assessment days. The following measures were analyzed on a post hoc basis: 1) percentages of patients meeting target levels of IOP reduction; 2) mean IOP reduction in those patients with high IOP (> or =30 mmHg) at baseline; 3) mean IOP at each of the assessment time points during a day. A total of 259 patients in the dorzolamide/timolol group and 268 patients in the latanoprost group were included in the efficacy analysis. At 3 months, both treatments showed similar efficacy with regard to the percentages of patients who achieved target levels of IOP reduction (e.g., 40% IOP reduction in 15% of dorzolamide/timolol combination patients and 13% of latanoprost patients), mean IOP reduction in those patients with high IOP at baseline (dorzolamide/ timolol combination, 12.5 mmHg, latanoprost, 12.6 mmHg), and mean IOP at each time point during the day. By the measures used in this analysis, the dorzolamide/timolol combination and latanoprost were equally effective at lowering IOP in patients with ocular hypertension or glaucoma.

Efficacy and tolerability of the dorzolamide 2%/timolol 0.5% combination (COSOPT) versus 0.005% (XALATAN) in the treatment of ocular hypertension or glaucoma: results from two randomized clinical trials.

PURPOSE: To compare the efficacy of the fixed dorzolamide 2%/timolol 0.5% combination (COSOPT) versus latanoprost 0.005% (XALATAN). METHODS: Two 3-month, parallel group, randomized, observer-masked and patient-masked, multicentre, clinical trials were performed in patients with ocular hypertension or open-angle glaucoma. Study 1 (n=256) was conducted in the United States and Study 2 (n=288) was conducted in Europe/Israel. Patients could be included whether or not they were currently taking ocular hypotensive therapy, and regardless of the effectiveness of any previous therapy. Patients were washed out from their usual ocular hypotensive medications and then those with a baseline intraocular pressure (IOP) >/= 24 mmHg were randomized to either the dorzolamide/timolol combination eye drops twice daily or latanoprost eye drops once daily in both eyes. Efficacy was assessed by daytime diurnal IOP (the mean of measurements made at 0800, 1000, 1400 and 1600 h). RESULTS: At baseline, the mean daytime diurnal IOP was 26.1 mmHg in the dorzolamide/timolol combination group versus 25.6 mmHg in the latanoprost group in Study 1, and 25.3 mmHg in the dorzolamide/timolol combination group versus 24.7 mmHg in the latanoprost group in Study 2. After 3 months, the mean daytime diurnal IOP was 18.9 mmHg for the dorzolamide/timolol combination versus 18.4 mmHg for latanoprost in Study 1, and 17.4 mmHg for the dorzolamide/timolol combination versus 17.5 for latanoprost in Study 2. The difference between treatments in mean IOP change at 3 months was -0.04 mmHg [95% confidence interval (CI) -0.85, 0.77] in Study 1, and -0.57 mmHg (95% CI -1.31, 0.16) in Study 2. The probability that the true difference lay between -1.5 and 1.5 mmHg, the predefined bounds for equivalence, was >0.950 in both studies. Both treatments were well tolerated over 3 months, although ocular stinging occurred more frequently with the dorzolamide/timolol combination. CONCLUSIONS: The dorzolamide/timolol combination and latanoprost were equally effective at lowering IOP.