Effect of beta-blockers on ventilatory function in smokers and non smokers.

Twenty healthy nonsmokers, 20 asymptomatic mild smokers and 20 asymptomatic moderate smokers were assessed for ventilatory functions, before and after equipotent dosages of atenolol, propranolol and oxprenolol in a single blind longitudinal study. The basal spirometric values were significantly lower in smokers than non smokers. After propranolol significant reduction was seen from basal values in FEV1, FEF 75%, MMFR, FEF 200-1200 in all the three groups. After oxprenolol significant difference was seen only with MMFR in the moderate smokers. With atenolol the variation was not significant in any group. Intercomparison of values after the drugs in each group was done. The values after propranolol was significantly lower than values after atenolol or oxprenolol for FEF 75%, MMFR and FEF 200-1200 in both the smoker groups whereas values after oxprenolol and Atenolol did not differ significantly from each other. Thus, in smokers atenolol offers a safe choice. If propranolol is to be used, the possibility of significant bronchospasm should be considered.