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

Abstract

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.

Effectiveness of Dorzolamide–Timolol (COSOPT) in Patients Who Were Treatment Naive for Open-Angle Glaucoma or Ocular Hypertension: The COSOPT First-Line Study

“…These findings are compatible with those reported by other authors who have shown equal efficacy of these 2 treatment regimens. [34][35][36] With respect to tolerability and safety, the profile and incidence of AEs observed in the present study were similar to those reported in randomized clinical trials, with local ocular reactions such as eye irritation and pain being the most common side effects followed by bitter taste. 24,33 As with other topical ophthalmic agents, systemic absorption of DT may occur and AEs associated with systemic administration of either active component may be expected.…”

“…33 Fechtner et al reported a mean change of À7.5 mmHg at 3 months of treatment from an untreated baseline value of 25.7 mmHg in patients treated with DT. 34,35 The mean reduction in IOP reported in the present study is higher than that observed in these randomized clinical trials and this may be attributed to the selection of patient with elevated IOP or with more advanced disease. At the end of 12 weeks of treatment, the effectiveness of the fixed combination of DT was similar to that observed for the patients who required treatment with latanoprost between 6 and 12 weeks.…”

Comparison of the efficacy of latanoprost versus dorzolamide/timolol fixed combination therapy in patients with pseudoexfoliative glaucoma according to glaucoma stage

“…Furthermore, in the staging of glaucoma, a variety of structural and functional testing methods are performed (18,20) . Many research groups have studied and compared the efficacy of CAI+β blocker fixed-dose combination therapy and PGAs inpatients with POAG (21)(22)(23)(24) . However, the IOP-lowering effects of these drugs may differ between PXG and POAG (4) , and only a few studies have compared PGA with CAI+β blocker fixed-dose combination therapy in PXG, none of which analyzed the influence of glaucoma stage on the IOP-lowering effect (25,26) .…”