A historical cohort study by Kirwan et al. «Kirwan JF, Nightingale JA, Bunce C ym. Do selectiv...»1 was performed to determine the incidence of airways obstruction in subjects with no previous history of airways obstruction, following treatment with topical beta antagonists for glaucoma for the period 1993–7.
For selective topical beta antagonists 12 of 324 treated subjects developed airways obstruction, compared with 112 of 9 094 controls (adjusted hazard rate 3.0, 95 % confidence interval 1.6 to 5.4). For non-selective topical beta antagonists, the corresponding figures were 69 of 2321 subjects compared with the same control group (adjusted hazard rate 2.2, CI 95 % 1.6 to 3.0). There was no significant difference between groups, p = 0.47, chi(2) test, both being associated with a significantly increased risk of airways obstruction.
Selective topical beta antagonists do appear to have an excess risk of airways obstruction in this population setting and should be subject to the same prescribing caveats as unselective topical beta antagonists.
Waldock at al «Waldock A, Snape J, Graham CM. Effects of glaucoma...»2 recruited 141 newly diagnosed glaucoma patients who underwent a full ocular, cardiovascular, and respiratory examination, including an electrocardiogram (ECG) and spirometry.
At the initial examination, 17 patients (13 %) had ECG evidence of first degree heart block, seven were prescribed latanoprost, six with brimonidine, and four with betaxolol. Eight patients were found to have arespiratory wheeze, four were prescribed brimonidine and the other four latanoprost. They were reviewed 3 months later. One eye of each patient was randomly chosen for analysis, performed using analysis of variance and the chi(2) test.
Timolol was associated with lowered pulse rates and reductions in the spirometry measurements. 41 % of patients using brimonidine complained of systemic side effects and over 55 % of patients using betaxolol complained of ocular irritation including dry eye. 28 % of patients required an alteration in their glaucoma management.
«Kirwan JF, Nightingale JA, Bunce C ym. Do selectiv...»1: There is no difference in pulmonary side effects between selective and non-selective beta blockers. Both are not recommended especially to those asthma patients, whose asthma is labil, i.e. not stable with regular asthma medication.
«Waldock A, Snape J, Graham CM. Effects of glaucoma...»2: Addional information of topical beta-blockers as the cause of bronchoconstriction or bradycardia in «http://www.ebmeds.org/ebmeds/ebmeds_home.asp?mode=scripts&submode=view&id=scr00597&country=UK»1.