title: Duration of IOP reduction with travoprost BAK-free solution.
abstract: OBJECTIVE
  To compare the duration of action of travoprost ophthalmic solution 0.004% (Travatan Z) formulated without benzalkonium chloride (BAK) to travoprost ophthalmic solution 0.004% formulated with BAK (Travatan).
  
  
  METHODS
  This was a prospective, randomized, double-masked study. Patients with open-angle glaucoma or ocular hypertension were randomized to receive 2 weeks of once-daily therapy with travoprost BAK-free or travoprost with BAK. Patients received the last dose of medication on day 13 and then intraocular pressure (IOP) was assessed every 12 hours for 60 hours. Statistical analysis included change in IOP from baseline for each group and comparison of mean IOP between groups.
  
  
  RESULTS
  Of the 109 patients enrolled, 106 patients completed the study. Untreated mean baseline IOP at 8 AM was 26.9 mm Hg in the travoprost BAK-free group and 27.1 mm Hg in the travoprost with BAK group. At 12, 24, 36, 48, and 60 hours after the last dose, mean IOP in the travoprost BAK-free group was 18.7, 17.2, 19.5, 18.7, and 20.8 mm Hg, respectively; whereas mean IOP in the travoprost with BAK group was 18.5, 16.8, 19.7, 18.0, and 20.8 mm Hg, respectively. Mean IOP at all time points after the last dose of medication was >6 mm Hg lower than the 8 AM baseline in both groups. Between-group differences were within +/-0.6 mm Hg at all postdose time points. There were no statistically significant differences between the 2 treatment groups at baseline or at any postdose time point. Drug-related side effects were uncommon, mild in intensity, and comparable between groups.
  
  
  CONCLUSIONS
  Travoprost without BAK has similar IOP-lowering efficacy and safety compared with travoprost preserved with BAK. Both formulations of travoprost have a prolonged duration of action, with statistically and clinically significant reductions from baseline persisting up to 60 hours after the last dose.
authors.affiliation: Ophthalmology, Baylor College of Medicine, Houston, TX, USA. rgross@bcm.tmc.edu
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Gross
authors.forename: James H
authors.initials: JH
authors.lastname: Peace
authors.forename: Stephen E
authors.initials: SE
authors.lastname: Smith
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Walters
authors.forename: Harvey B
authors.initials: HB
authors.lastname: Dubiner
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Weiss
authors.forename: Katherine I
authors.initials: KI
authors.lastname: Ochsner
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000009:adverse effects; D001548:Benzalkonium Compounds / Q000008:administration & dosage* / Q000009:adverse effects; D003008:Cloprostenol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D004311:Double-Blind Method; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D009798:Ocular Hypertension / Q000188:drug therapy; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000009:adverse effects; D011310:Preservatives, Pharmaceutical / Q000008:administration & dosage* / Q000009:adverse effects; D011446:Prospective Studies; D013997:Time Factors; D014065:Tonometry, Ocular; D000069557:Travoprost
chemical_list: D000959:Antihypertensive Agents; D001548:Benzalkonium Compounds; D009883:Ophthalmic Solutions; D011310:Preservatives, Pharmaceutical; D003008:Cloprostenol; D000069557:Travoprost