THE EFFICACY OF APRACLONIDINE AS AN ADJUNCT TO TIMOLOL THERAPY

Objective: To compare the intraocular pressure (IOP) lowering efficacy of 0.5% and 1.0% apraclonidine hydrochloride when used adjunctively w ith 0.5% timolol maleate in 129 patients. Design: A multicenter, rando mized, double-masked clinical trial. Adult patients of either sex diag nosed as having either open-angle glaucoma or ocular hypertension were enrolled in the study, Patients using only 0.5% timolol maleate twice daily for at least 4 weeks and who had 8 AM IOPs of at least 22 mm Hg and no greater than 30 mm Hg 12 hours after dosing were eligible for the study. After 8 AM baseline IOPs were obtained while patients were taking timolol only, they were then randomized to receive either 0.5% or 1.0% apraclonidine twice daily in addition to their timolol. Intrao cular pressures were measured at 8 AM (before morning dosing) and at 1 1 AM (3 hours after dosing) on days 14 and 90 and at 8 AM only on day 45. Results: Both concentrations of apraclonidine produced significant IOP reductions from baseline at all visits (P < .001). At 8 AM, after the nighttime dose, the additional mean IOP reduction from the timolo l baseline ranged from 2.5 to 3.3 mm Hg (10.3% to 13.6% reduction, res pectively). At 11 AM, 3 hours after the morning dose, the additional I OP reduction from the timolol baseline ranged from 4.7 to 5.2 mm Hg (2 0.0% to 21.7%, re spectively). No difference in IOP reduction was obse rved between the 0.5% and 1.0% apraclonidine concentrations and no los s of IOP efficacy was observed for either concentration for the durati on of the study. Sensitivity to 0.5% and 1.0% apraclonidine was observ ed in nine (13.8%) and 13 (20.3%) patients, respectively. Overall, the rapy was discontinued owing to ocular or nonocular side effects with 0 .5% and 1.0% apraclonidine in 14 (21.5%) and 16 (25%) patients, respec tively. Conclusions: We believe that 0.5% apraclonidine is equally eff ective as 1.0% apraclonidine when used twice daily as the first adjunc tive drug to timolol. The drug effect is maintained for at least 90 da ys.