A comparison of once-daily morning vs evening dosing of concomitant latanoprost/timolol.

Purpose: To evaluate morning vs evening once daily concomitant latanoprost 0.005%/timolol maleate 0.5% therapy in ocular hypertensive or primary open-angle glaucoma patients.

Design: Prospective single-center double-masked crossover comparison.

Methods: Patients who responded to timolol maleate 0.5% given twice daily were randomized to either evening or morning dosing of concomitant latanoprost 0.005% and timolol maleate 0.5% therapy for 7 weeks. Twenty-four hour diurnal curve intraocular pressure (IOP) testing was performed following each period.

Results: Thirty-six patients completed this study. There was a significant reduction at each time point in the 24-hour diurnal curve of both evening (17.1 +/- 2.7 mm Hg) and morning (17.3 +/- 3.1 mm Hg) dosed latanoprost/timolol maleate compared with timolol maleate given twice daily (21.1 +/- 3.3 mm Hg) (P <.0001). When the morning and evening dosing groups were compared directly, the 06:00 time point was statistically lower with evening dosing (16.4 +/- 2.3 mm Hg) vs morning dosing (17.9 +/- 2.8 mm Hg) (P =.01). Overall, a trend existed for greater daytime reduction with night-time dosing of the concomitant therapy, whereas morning dosing tended to give lower night-time pressures. There was a significantly lower mean range of diurnal pressure with evening (3.6 mm Hg) vs morning (4.3 mm Hg) dosing (P =.02). No differences in adverse events existed between the treated arms.

Conclusions: This study suggests that latanoprost and timolol maleate, both given once daily in the morning or evening, effectively reduce the IOP for the 24-hour diurnal curve when compared with timolol maleate twice daily.