Do selective topical beta antagonists for glaucoma have respiratory side effects?

Background/aims: Topical beta antagonists are prescribed for glaucoma in approximately 500 000 people in the United Kingdom. The authors have previously shown that topical beta antagonists are associated with an excess incidence of airways obstruction. They examined whether selective topical beta antagonists are associated with excess airways obstruction.
Methods: A historical cohort study 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. Cases were defined as having received a first prescription of a drug specifically used in the management of airways obstruction.
Results: For selective topical beta antagonists 12 of 324 treated subjects developed airways obstruction, compared with 112 of 9094 controls (adjusted hazard rate 3.0 (95% confidence interval (95% CI) 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 (1.6 to 3.0)). There was no significant difference between groups (p = 0.47, chi(2)), both being associated with a significantly increased risk of airways obstruction.
Conclusion: 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.