Safety and efficacy of switching from dorzolamide 1.0%/timolol maleate 0.5% eye drops to brinzolamide 1.0%/timolol maleate 0.5% eye drops

PURPOSE: To evaluate the safety and efficacy of switching from dorzolamide 1.0%/timolol maleate 0.5% fixed-combination (DTFC) eye drops to brinzolamide 1.0%/timolol maleate 0.5% fixed-combination (BTFC) eye drops in patients with primary open-angle glaucoma or ocular hypertension. METHODS: A total of 35 eyes of 35 patients with primary open-angle glaucoma or ocular hypertension using DTFC eye drops were included. Participants discontinued DTFC drops and immediately began using BTFC drops. All other eye drops currently being used were continued. Intraocular pressure (IOP) 1 and 3 months after switching medications was compared with baseline IOP. One month after switching medications, participant preference and adherence were evaluated. Adverse reactions were monitored at each study visit. RESULTS: The IOP was 17.9±2.6 mmHg at baseline and 18.3±4.1 mmHg and 17.8±3.4 mmHg 1 month and 3 months after switching medications, respectively (P=0.633). The frequency of missing a dose was not different before (6.1%) and after (6.1%) switching to BTFC. Significantly fewer participants reported stinging after switching to BTFC (15.2%) than while using DTFC (51.5%, P,0.01). Blurred vision was reported with the same frequency before (39.4%) and after (42.4%) switching to BTFC. A total of 33.3% and 27.3% of patients preferred DTFC and BTFC, respectively. Several patients withdrew from the study because of discomfort (n=2, 5.7%), discharge (n=1, 2.9%), dizziness (n=1, 2.9%), or increased IOP (n=2, 5.7%). CONCLUSION: Switching from DTFC to BTFC was well tolerated and did not result in IOP changes or a decreased patient adherence. When glaucoma patients complain of stinging with DTFC administration, switching to BTFC is an acceptable treatment option.