title: Intraocular pressure over 24 hours after single-dose administration of latanoprost 0.005% in healthy volunteers. A randomized, double-masked, placebo controlled, cross-over single center study.
abstract: OBJECTIVE
  To measure the effect on intraocular pressure (IOP) over 24 hours after single-dose administration of latanoprost 0.005%.
  
  
  METHODS
  A randomized, double-masked placebo-controlled cross-over study was carried out. Twenty healthy volunteers were randomly assigned to receive a single drop of latanoprost 0.005% or placebo, with a 2-week wash-out period before switching therapy. After hospitalization, the IOP was measured repeatedly over 24 hours, and again after 36 and 48 hours.
  
  
  RESULTS
  The maximum IOP reduction for latanoprost occurred 12 hours after the dose with IOP 11.7+/-0.5 mmHg (least square mean+/-standard standard error of the mean [SEM]) for latanoprost and 13.5+/-0.5 mmHg for placebo. The difference of 1.8+/-0.6 mmHg was statistically significantly in favor of latanoprost (p=0.01; ANCOVA, confidence interval (CI) [-3.1; -0.5] mmHg). The average time to onset of action, defined as 50% of the maximal IOP reduction, was 6.0 hours for latanoprost. Latanoprost consistently reduced IOP over 24 hours after drop application with a difference in IOP reduction of 1.1+/-0.5 mmHg (p=0.03, CI [-2.1, 0.1]) at 24 hours. The corresponding IOP difference at 36 hours was 0.7+/-0.5 mmHg (p=0.20, CI [-1.7, 0.3]), and at 48 hours 0.8+/-0.5 mmHg (p=0.04, CI [-1.5, 0.0]).
  
  
  CONCLUSIONS
  Latanoprost applied as a single dose reduced IOP over 24 hours in healthy subjects compared with placebo. The IOP reduction was still present, however, less pronounced, 48 hours after drug application.
authors.affiliation: Department of Ophthalmology, Uppsala University Hospital, S-751 85 Uppsala, Sweden. Lill-Inger.Larsson@ogon.uu.se
authors.forename: L I
authors.initials: LI
authors.lastname: Larsson
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage*; D002940:Circadian Rhythm / Q000187:drug effects*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage*
chemical_list: D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost