Association between topical β-blocker use and asthma attacks in glaucoma patients with asthma: a cohort study using a claims database

Purpose: To investigate the association between the use of topical β-blockers and subsequent asthma attacks in glaucoma patients with asthma. Methods: This was a retrospective longitudinal cohort study using an administrative claims database. All patients aged 20 years or older who were registered in the health insurance claims database updated and managed by JMDC Inc. (Tokyo, Japan). Patients who were newly prescribed eye drops for glaucoma treatment were identified between 2011 and 2017. The patients with glaucoma were divided into two groups: β-blocker users and non-β-blocker users, based on the presence of a β-blocker in the prescribed eye drops. We investigated whether the incidence of asthma attacks in patients with previously treated asthma differed between the two groups. Results: We categorized 17,666 patients in the β-blocker-user group and 12,609 patients in the non-β-blocker-user group. A total of 580 patients in the β-blocker group (3.28%) and 847 in the non-β-blocker group (6.72%) underwent asthma treatment before the prescription of anti-glaucoma eye drops (P < 0.001). Furthermore, 94 patients in the β-blocker-user group (0.53%) and 278 in the non-β-blocker user group (2.20%) were undergoing current treatment for asthma (P < 0.001). The adjusted hazard ratios of asthma attacks were 0.73 (95% confidence interval, 0.46–1.16, P = 0.18) in patients with a history of asthma treatment and 1.22 (95% confidence interval, 0.56–2.70, P = 0.62) in patients with current asthma treatment, compared to the non-β-blocker-user group. Conclusion: Our results clarified that several patients with asthma were prescribed topical β-blockers for glaucoma treatment. However, asthma attacks may not be significantly attributed to topical β-blockers, even in glaucoma patients under current asthma treatment. The administration of topical β-blockers to asthma patients could be a treatment option in the absence of other treatment options, if adequate informed consent is obtained. Further studies are needed to draw a firm conclusion on this clinical question.[Figure not available: see fulltext.].