THE EFFICACY AND SAFETY OF DORZOLAMIDE AS ADJUNCTIVE THERAPY TO TIMOLOL MALEATE GELLAN SOLUTION IN PATIENTS WITH ELEVATED INTRAOCULAR-PRESSURE

Purpose: Two parallel, randomized, double-masked, placebo-controlled s tudies were conducted to assess the efficacy and safety of 28 dorzolam ide hydrochloride as adjunctive therapy to 0.5% timolol maleate ophtha lmic gellan (gel-forming) solution in patients with elevated intraocul ar pressure (IOP) that was inadequately controlled with 0.5% timolol m aleate gellan solution alone. Methods: Both studies began with an open -label 2-week run-in period on 0.5% timolol maleate gellan solution on ce a day. The only variation in method between the two studies was the dosage of 2% dorzolamide. In one study, 202 patients received 0.5% ti molol maleate gellan solution once daily plus either 2% dorzolamide or placebo three times daily. In the other study, 181 patients received 0.5% timolol maleate gellan solution once daily plus either 2% dorzola mide or placebo twice daily. Results: After 85 days, additional mean p ercent reductions in IOP from baseline at morning trough for the group s receiving 2% dorzolamide three times daily and placebo three times d aily were 12.5% and 8.4%, respectively. Mean percent reductions for th e groups receiving 2% dorzolamide twice daily and placebo twice daily were 13.1% and 6.5%, respectively. Burning and/or stinging on instilla tion were the only adverse experiences that affected significantly mor e of the patients receiving 2% dorzolamide twice or three times daily than those receiving placebo. Conclusion: When administered concomitan tly with 0.5% timolol maleate gellan solution, 2% dorzolamide three ti mes daily or twice daily produced a statistically significant reductio n in IOP at morning trough and peak and was generally well tolerated.