24-hour control of intraocular pressure with 2% dorzolamide/0.5% timolol fixed-combination ophthalmic solution in open-angle glaucoma.
OBJECTIVE
To evaluate the 24-hour efficacy and tolerability of 2% dorzolamide/0.5% timolol fixed combination (DTFC) solution in open-angle glaucoma and ocular hypertension.


METHODS
Randomized, parallel, double-masked, multicenter study. Patients with insufficiently controlled intraocular pressure (IOP > or = 22 mmHg) were randomized to DTFC (N = 117) or timolol (N = 115). IOP was measured at baseline, 6 weeks, and 8 weeks, with measurements taken at 6 p.m., 8 p.m., 10 p.m., 2 a.m., 6 a.m., 8 a.m., 10 a.m., and 2 p.m. ClinicalTrials. gov identifier: NCT00108017 MAIN OUTCOME MEASURES: Statistically significant change in IOP from untreated baseline for DTFC at all hours at week 8. Secondary outcome measures included: IOP-lowering at week 6 at all individual time points, change from baseline to 8 weeks in mean daytime IOP (average of 8 a.m., 10 a.m., 2 p.m., 6 p.m., and 8 p.m. IOPs) and night-time IOP (10 p.m., 2 a.m., 6 a.m.), and comparison of DTFC with timolol after 8 weeks.


RESULTS
Patients receiving DTFC had a statistically significant and clinically relevant reduction in IOP at week 8 compared with baseline at all eight time points (p < 0.001). Significant IOP reductions were also seen at all time points at week 6 (p < 0.001). DTFC significantly lowered mean daytime IOP and night-time IOP ( p < 0.001 for both). Timolol alone also significantly reduced IOP from baseline at 8 weeks for all diurnal time points, and mean daytime and night-time IOP ( p < 0.001 for all). Compared with timolol alone, there were significantly greater reductions with DTFC at 10 a. m. (p = 0.003) and 2 p. m. (p = 0.016), and for mean daytime IOP (p = 0.025) at 8 weeks. Significant between-treatment differences were not observed at other time points. Both treatments were well-tolerated, with no differences observed in the safety profiles between the treatment groups.


CONCLUSIONS
Both DTFC and timolol provided significant IOP reduction over the entire 24-hour measurement period. Although this study was not designed or powered to compare DTFC and timolol, DTFC exhibited greater IOP-lowering than timolol during the daytime, but not at night.
Feldman
Robert M
RM
University of Texas Health Science Center at Houston, Houston, TX 77030, USA. rmfeldman@swbell.net
Stewart
Robert H
RH
Stewart
William C
WC
Jia
Gang
G
Smugar
Steven S
SS
Galet
Vincent A
VA
D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002257:Carbonic Anhydrase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009883:Ophthalmic Solutions; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D013876:Thiophenes / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D013999:Timolol / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
D000319:Adrenergic beta-Antagonists; D002257:Carbonic Anhydrase Inhibitors; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; D013999:Timolol; C062765:dorzolamide