title: A short term study of the additive effect of timolol and brimonidine on intraocular pressure.
abstract: OBJECTIVE
  To evaluate the additive ocular hypotensive effect of the combination of brimonidine and timolol on intraocular pressure (IOP) reduction in patients with glaucoma.
  
  
  METHODS
  This was a prospective, randomized, double-masked, crossover study in 20 patients with primary open angle glaucoma (POAG) on therapy receiving timolol maleate 0.5% twice daily, with IOP greater than or equal to 22 mmHg in one eye. The treatment period was 3 weeks and during this period timolol + brimonidine or timolol + placebo were applied topically twice daily and IOP, blood pressure, heart rate and pupil size were measured.
  
  
  RESULTS
  Combined therapy (timolol + brimonidine) had clinically significant IOP-lowering effect during the treatment period P << 0.01). The mean diurnal IOP was significantly reduced by an average of 5.1-5.9 mmHg (21.2-24.5%) compared with baseline value. The timolol + placebo combination had no clinically significant IOP-lowering effect (P > 0.05). No clinically significant side effects were observed during the treatment of both groups.
  
  
  CONCLUSIONS
  This study showed that the combination of topically applied brimonidine and timolol cause a marked and sustained IOP reduction.
authors.affiliation: Department of Ophthalmology, Cumhuriyet University School of Medicine Sivas, Turkey. kemalarici@hotmail.com
authors.forename: M K
authors.initials: MK
authors.lastname: Arici
authors.forename: M
authors.initials: M
authors.lastname: Sayici
authors.forename: Mi
authors.initials: M
authors.lastname: Toker
authors.forename: H
authors.initials: H
authors.lastname: Erdoğan
authors.forename: A
authors.initials: A
authors.lastname: Topalkara
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000627:therapeutic use*; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects; D000068438:Brimonidine Tartrate; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011810:Quinoxalines / Q000627:therapeutic use*; D013999:Timolol / Q000627:therapeutic use*
chemical_list: D000316:Adrenergic alpha-Agonists; D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D011810:Quinoxalines; D000068438:Brimonidine Tartrate; D013999:Timolol