The undesirable effects of two beta-blockers on pulmonary function were compared both in normal subjects and in stable asthmatic patients using a cross-over method.
1. In 11 normal subjects, significant lowering of SGaw and FVC occurred at each observation point around 2 hrs after administration of timolol in contrast, no. signifi cant change was noted after arotinolol.
2. In 6 patients with asthma in a stable stage, timolol reduced SGaw at 30 min, 1, 2, and 3 hrs after administration while arotinolol induced small reduction in only 30 min after the administration. The change by administration of timolol was significantly greater than that by arotinolol at any measured point.
3. Two out of 6 patients experienced wheezing to a slight degree only after timolol.
These results suggest that arotinolol, with its weak alpha-blocking action, will be safer for patients with asthma or chronic obstructive lung diseases than timolol, which shows potent effect on respiratory function even after occular topical use.
