[Propranolol and pindolol in chronic obstructive lung disease (author's transl)]

The effects of 5 mg pindolol and 100 mg propranolol on the airway resistance were compared with a placebo in an inter-individual double blind trial in eight patients with chronic obstructive lung disease. Six hours after drug administration the patients inhaled two puffs of fenoterol (0.4 mg) from a metered aerosol to test the reversibility of the bronchoconstrictive effect. Airway resistance and intrathoracic gas volume were measured by body plethysmography. Propranolol increased the airway resistance significantly (P less than 0.01). The highest increase with a mean of 44% was measured two hours after ingestion. After six hours the mean increase was still 18%. Pindolol showed a barely detectable, statistically insignificant bronchoconstrictive effect in comparison with the placebo. With regard to the circulatory effects 5 mg pindolol and 100 mg propranolol were aequipotent, propranolol had a more pronounced effect in lowering the pulse rate, pindolol in lowering the blood pressure. Fenoterol can reduce airway resistance even after beta-blockade, but the effect was more profound after the placebo than after the beta-blocker.