[Effects of beta blockaders on ventilatory function in chronic bronchitis].

This study was carried out to determine whether beta blockers could be prescribed for patients with coronary insufficiency and chronic bronchitis. The effects of intravenous infusions (30 mn) of propranolol (30 micrograms/kg), practolol 90 micrograms/kg), atenolol (90 micrograms/kg) and acebutolol (150 micrograms/kg) on vital capacity and expiratory flow rates were investigated in chronic bronchitics. Propranolol (n = 51) moderately reduced the vital capacity and FEV1, by an average 9% and a maximum of 20%. The three other infused agents given to groups of 10 patients did not change the ventilatory function. When the same patients were investigated by cross over with propranol bronchoconstriction was observed. This effect was seen in all stages of chronic bronchitis but was much less severe than in a group of 50 asthmatic patients (-23%). The respiratory tolerance of the cardioselective beta blockers seems to be better but there is considerable individual variation and the diagnosis between asthma and chronic bronchitis may itself be very difficult.