Three-month evaluation of dorzolamide hydrochloride/timolol maleate fixed-combination eye drops versus the separate use of both drugs.

PURPOSE: To investigate the ocular hypotensive effect and safety of dorzolamide hydrochloride 1 %/timolol maleate 0.5 % fixed-combination eye drops.

METHODS: The study cohort comprised 34 patients with either primary open-angle glaucoma or ocular hypertension who were being concomitantly treated with dorzolamide hydrochloride 1 % eye drops and timolol maleate 0.5 % eye drops. The dorzolamide hydrochloride 1 % and timolol maleate 0.5 % eye drops were replaced with dorzolamide hydrochloride 1 %/timolol maleate 0.5 % fixed-combination eye drops without any washout period. The intraocular pressure (IOP) was evaluated both before and 1 and 3 months after the treatment change. The patients were asked to complete a questionnaire on adherence to the treatment protocol 1 month after the change in treatment.

RESULTS: The IOP was 15.5 ± 2.7 mmHg at the time of treatment change, 15.2 ± 2.7 mmHg at 1 month post-change, and 15.5 ± 2.9 mmHg at 3 months post-change, which is consistent with that before the treatment change (p = 0.286). Based on the completed questionnaire, following the treatment change, 50 % of patients felt a stinging sensation following administration of the eye drops and 11.8 % experienced blurred vision. In no case were the eye drops discontinued due to adverse reactions or insufficient IOP decrease.

CONCLUSION: The replacement of concomitant treatment with dorzolamide hydrochloride 1 % and timolol maleate 0.5 % eye drops with dorzolamide hydrochloride 1 %/timolol maleate 0.5 % fixed-combination eye drops improved protocol adherence and preserved the IOP.