beta-Adrenoceptor blockade and pulmonary function in patients suffering from chronic obstructive lung disease.

Pulmonary function can be reduced by beta-blockers. It has been established that no beta-blocker is entirely safe in patients with chronic obstructive lung disease. An alternative medication not expected to influence pulmonary function should first be considered. This side effect of beta-blockers develops mostly in patients with reversible bronchial obstruction, and it is much less pronounced in those with irreversible bronchial obstruction. Translated into terms of clinical diagnosis, this means that problems should be expected in patients with bronchial asthma and with asthmatic bronchitis, whereas those with chronic bronchitis and emphysema are much less likely to develop relevant symptoms. It has been demonstrated that beta-blockers with intrinsic sympathomimetic activity (ISA), such as pindolol, and beta 1-selective blockers have a less marked effect on pulmonary function than nonselective beta-blockers without ISA, such as propranolol. The untoward effect can be compensated by combination with a beta-mimetic agent; this mechanism is most effective during beta 1-selective blockade.