title: The efficacy of apraclonidine as an adjunct to timolol therapy. Apraclonidine Adjunctive Therapy Study Group.
abstract: OBJECTIVE
  To compare the intraocular pressure (IOP) lowering efficacy of 0.5% and 1.0% apraclonidine hydrochloride when used adjunctively with 0.5% timolol maleate in 129 patients.
  
  
  METHODS
  A multicenter, randomized, double-masked clinical trial. Adult patients of either sex diagnosed 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. Intraocular pressures were measured at 8 AM (before morning dosing) and at 11 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 timolol baseline ranged from 2.5 to 3.3 mm Hg (10.3% to 13.6% reduction, respectively). At 11 AM, 3 hours after the morning dose, the additional IOP reduction from the timolol baseline ranged from 4.7 to 5.2 mm Hg (20.0% to 21.7%, respectively). No difference in IOP reduction was observed between the 0.5% and 1.0% apraclonidine concentrations and no loss of IOP efficacy was observed for either concentration for the duration of the study. Sensitivity to 0.5% and 1.0% apraclonidine was observed in nine (13.8%) and 13 (20.3%) patients, respectively. Overall, therapy was discontinued owing to ocular or nonocular side effects with 0.5% and 1.0% apraclonidine in 14 (21.5%) and 16 (25%) patients, respectively.
  
  
  CONCLUSIONS
  We believe that 0.5% apraclonidine is equally effective as 1.0% apraclonidine when used twice daily as the first adjunctive drug to timolol. The drug effect is maintained for at least 90 days.
authors.affiliation: Medical University of South Carolina, Charleston, USA.
authors.forename: W C
authors.initials: WC
authors.lastname: Stewart
authors.forename: R
authors.initials: R
authors.lastname: Ritch
authors.forename: D H
authors.initials: DH
authors.lastname: Shin
authors.forename: R P
authors.initials: RP
authors.lastname: Lehmann
authors.forename: C E
authors.initials: CE
authors.lastname: Shrader
authors.forename: E M
authors.initials: EM
authors.lastname: van Buskirk
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant; D003000:Clonidine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004357:Drug Synergism; D004361:Drug Tolerance; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D009883:Ophthalmic Solutions; D013999:Timolol / Q000627:therapeutic use*
chemical_list: D000316:Adrenergic alpha-Agonists; D009883:Ophthalmic Solutions; D013999:Timolol; C016986:apraclonidine; D003000:Clonidine