Topical beta-blockade with intrinsic sympathomimetic activity offers no advantage for the respiratory and cardiovascular function of elderly people

Abstract

Topical therapy with beta-antagonists, such as timolol, may cause unrecognized impairment of respiratory and cardiovascular function in elderly people. Beta-antagonists with intrinsic sympathomimetic or cardioselective properties, such as carteolol or betaxolol, may cause less impairment. In a randomized, double-masked study of glaucoma patients, over 60 years of age, without history of bronchospasm and who were using timolol (0.5%), 60 patients were allocated to betaxolol (0.5%) or carteolol (2%) or continued timolol (0.5%) treatment. Spirometry, pulse and blood pressure were measured on enrollment and after 4 weeks. In the timolol and carteolol groups there were no significant changes in mean spirometric values. Changing to betaxolol improved mean peak flow (PF) by 9.1%, from 310 to 3411/min (p < 0.05) and forced expiratory volume in 1 second (FEV1) by 9.4%, from 1.74 to 1.861 (p < 0.05). Differences in the changes in PF and FEV1 between betaxolol and timolol as well as betaxolol and carteolol groups were statistically significant (p < 0.05). Twenty-one per cent of those allocated to betaxolol showed clinically significant improvement in FEV1. There was no change in pulse or blood pressure when carteolol was substituted for timolol but an increase of 10 beats per minute (p < 0.05) in mean resting pulse in the betaxolol group. Therapy with cardioselective beta-blockade may offer significant advantages in respiratory function for elderly people with glaucoma over non-selective drugs, even if they have sympathomimetic activity.