TOPICAL BETA-BLOCKADE WITH INTRINSIC SYMPATHOMIMETIC ACTIVITY OFFERS NO ADVANTAGE FOR THE RESPIRATORY AND CARDIOVASCULAR FUNCTION OF ELDERLY PEOPLE

Topical therapy with beta-antagonists, such as timolol, may cause unre cognized impairment of respiratory and cardiovascular function in elde rly people. Beta-antagonists with intrinsic sympathomimetic or cardios elective properties, such as carteolol or betaxolol, may cause less im pairment. In a randomized, double-masked study of glaucoma patients, o ver 60 years of age, without history oi bronchospasm and who were usin g timolol (0.5%), 60 patients were allocated to betaxolol (0.5%) or ca rteolol (2%) or continued timolol(0.5%) treatment. Spirometry, pulse a nd blood pressure were measured on enrolment and after 4 weeks. In the timolol and carteolol groups there were no significant changes in mea n spirometric values. Changing to betaxolol improved mean peak flow (P F) by 9.1% from 310 to 3411/min (p < 0.05) and forced expiratory volum e in 1 second (FEV(1)) by 9.4%, from 1.74 to 1.861(p < 0.05). Differen ces in the changes in PF and FEV(1) between betaxolol and timolol as w ell 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 FEV(1). There was no change in p ulse 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-blockers may o ffer significant advantages in respiratory function for elderly people with glaucoma over non-selective drugs, even if they have sympathomim etic activity.