THE COMBINED EFFECTS OF INHALED DISODIUM CROMOGLYCATE WITH β-STIMULANT ON HYPEROSMOLAR INDUCED BROCHOSPASM

To investigate the combined effects of inhaled DSCG with β-stimulant for the prevention of bronchospasm induced by hyperosmolar challenges, 10 asthmatic children had eight hyperosmolar challenge tests in a randomised order. 3 tests were performed at 15min after the inhalation of either saline (control: C), DSCG (D), or salbutamol (S). 5 tests were performed at 180min after the inhalation of either C, D, S, salbutamol followed by DSCG (S→D) or DSCG mixed with salbutamol (S+D). Although FEV1.0 significantly increased untill 180min after inhalation in groups of S, S→D and S+D, there were no significant differences between each group. No synergetic effect occurred in the bronchodilating response to the inhalation of DSCG with salbutamol. In both the D and S groups, the dose of hypersaline provoking the 20% decrement in FEV1.0 (PD20) increased at 15min after inhalation. This protective effect of inhaled DSCG almost disappeared at 180min. PD20 in both the S→D and S+D groups significantly increased as compared to the S group at 180min after inhalation (p<0.05). There were, however, no significant differences in PD20 between the S→D and S+D groups. To evaluate further whether PD20 was influenced by doses of inhaled DSCG, PD20 was measured at 180min after the inhalation of 10mg/ml or 20mg/ml of DSCG. PD20 did not significantly increase in 20mg/ml of DSCG.This suggests that the combination of inhaled DSCG with salbutamol may produce a synergetic protective effect against the hyperosmolar challenge test.