title: Timolol hemihydrate vs timolol maleate to treat ocular hypertension and open-angle glaucoma.
abstract: OBJECTIVE
  We compared the therapeutic efficacy and safety of timolol hemihydrate to timolol maleate in patients with ocular hypertension and chronic open-angle glaucoma.
  
  
  METHODS
  We conducted this three-month study as a multicentered, masked, parallel group comparison. Both the 0.25% and 0.5% concentrations were evaluated against similar concentrations of timolol maleate. Dosing was twice daily. An open-label, nine-month study followed the masked portion of the protocol, in which all patients received either 0.25% or 0.5% timolol hemihydrate. A total of 371 patients were included in both the 0.25% and 0.5% studies.
  
  
  RESULTS
  We found statistically similar intraocular pressures with both the 0.25% (18.3 and 18.6 mm Hg for the hemihydrate and maleate groups, respectively) and 0.5% (19.9 and 19.5 mm Hg for the hemihydrate and maleate groups, respectively) concentrations of timolol hemihydrate and timolol maleate after three months of masked treatment. Likewise, peak intraocular effect at two hours after taking the medication was statistically similar between medicines at both concentrations. Likewise, both ocular and systemic safety were similar between the maleate and hemihydrate preparations at both concentrations. In the nine-month open-label protocol, therapeutic efficacy (19.9 and 19.1 mm Hg for the 0.25% and 0.5% concentrations, respectively) and safety of timolol hemihydrate were similar to effect and safety of the three-month protocol.
  
  
  CONCLUSIONS
  This study suggests that timolol hemihydrate had an ocular hypotensive efficacy and safety profile statistically equivalent to that of timolol maleate for up to three months of therapy. Timolol hemihydrate showed efficacy and safety similar to that observed within the first three months, for up to one year of therapy.
authors.affiliation: Clayton Eye Center, Morrow, Georgia, USA.
authors.forename: H B
authors.initials: HB
authors.lastname: DuBiner
authors.forename: R
authors.initials: R
authors.lastname: Hill
authors.forename: H
authors.initials: H
authors.lastname: Kaufman
authors.forename: E U
authors.initials: EU
authors.lastname: Keates
authors.forename: T J
authors.initials: TJ
authors.lastname: Zimmerman
authors.forename: A I
authors.initials: AI
authors.lastname: Mandell
authors.forename: T K
authors.initials: TK
authors.lastname: Mundorf
authors.forename: R L
authors.initials: RL
authors.lastname: Bahr
authors.forename: L W
authors.initials: LW
authors.lastname: Schwartz
authors.forename: A W
authors.initials: AW
authors.lastname: Towey
authors.forename: L M
authors.initials: LM
authors.lastname: Hurvitz
authors.forename: R J
authors.initials: RJ
authors.lastname: Starita
authors.forename: J W
authors.initials: JW
authors.lastname: Sassani
authors.forename: A
authors.initials: A
authors.lastname: Ropo
authors.forename: R
authors.initials: R
authors.lastname: Gunn
authors.forename: W C
authors.initials: WC
authors.lastname: Stewart
mesh_terms: D000293:Adolescent; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001794:Blood Pressure; D002908:Chronic Disease; D004311:Double-Blind Method; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006339:Heart Rate; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy*; D009883:Ophthalmic Solutions; D012449:Safety; D013999:Timolol / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: D000319:Adrenergic beta-Antagonists; D009883:Ophthalmic Solutions; D013999:Timolol