A RANDOMIZED TRIAL IN PATIENTS INADEQUATELY CONTROLLED WITH TIMOLOL ALONE COMPARING THE DORZOLAMIDE-TIMOLOL COMBINATION TO MONOTHERAPY WITHTIMOLOL OR DORZOLAMIDE

Objective: To compare the dorzolamide-timolol fixed combination twice daily to its components, timolol maleate and dorzolamide hydrochloride , given in their usual monotherapy regimens in patients whose intraocu lar pressure (IOP) was not controlled on timolol twice daily alone. De signs: Parallel, randomized, double-masked, and active-controlled stud y. Participants: Enrolled were 253 patients from 22 sites throughout t he United States. Intervention: After a 3-week run-in of timolol (TIMO PTIC; Merck & Co., Inc., Whitehouse Station, NJ) twice daily, eligible patients received either the combination (COSOPT; Merck & Co., Inc., Whitehouse Station, NJ) twice daily (plus placebo to ensure masking), timolol twice daily (plus placebo to ensure masking), or dorzolamide ( TRUSOPT; Merck & Co. Inc., Whitehouse Station, NJ) three times daily f or 3 months. Main Outcome Measures: intraocular pressure taken at hour s 3 (trough) and 2 (peak) after week 2 and months 1, 2, and 3 was comp ared to baseline within each treatment group and between the combinati on and each component group. The safely profile of the combination was compared to each component. Results: The combination was numerically superior at all study timepoints and was statistically superior at all timepoints except for month 2, hour 0 for timolol, and month 2, hour 2 for dorzolamide. The safety profile of the combination reflected tho se of its two components. The number of patients reporting ocular or l ocal adverse experiences was greater for the combination (45%) and dor zolamide (45%) than for timolol (27%), with burning and/or stinging ey e being the most frequently reported, Conclusion: The dorzolamide-timo lol combination provides additional IOP lowering compared to either of its individual components and generally is well-tolerated.