The protective property of equipotent bronchodilating doses of inhaled KWD 2131 and terbutaline against allergen-induced bronchospasm.
The anti-allergic capacity of nebulized KWD 2131 in inhibiting allergen-induced bronchospasm was compared with that of terbutaline in equipotent bronchodilating doses. It was a double-blind cross-over and randomized study also including placebo. Twelve symptom-free extrinsic asthmatics participated in the trial. Equipotent bronchodilating doses of the two beta-receptor-agonists were established in a histamine challenge procedure before the start of the study. Allergen challenge was performed with double concentration steps every 10 min until a greater than or equal to 20% decrease in FEV1 was achieved. Significantly (P less than 0.001) more allergen dose steps could be used after pretreatment with KWD 2131 and terbutaline than with placebo. No difference could be observed between the active compounds. The same allergen log dose gave a 20% decrease in FEV1 after pretreatment with KWD 2131 and terbutaline. The active compounds' protective properties did not differ at a lower degree of allergen challenge. The plasma histamine level was not significantly changed at any point of allergen challenge after pretreatment with either placebo or the active compounds. Therefore, plasma histamine determination was of no value for evaluating the inhibition of mediator release by these drugs. It is concluded that the anti-allergic property of KWD 2131 at allergen challenge does not give any further clinical value besides the bronchodilating property.
D000281:Administration, Intranasal; D000328:Adult; D000485:Allergens / Q000008:administration & dosage; D001985:Bronchial Provocation Tests; D001986:Bronchial Spasm / Q000175:diagnosis / Q000188:drug therapy*; D001993:Bronchodilator Agents / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume; D006632:Histamine / Q000097:blood; D006801:Humans; D008297:Male; D013726:Terbutaline / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use*
D000485:Allergens; D001993:Bronchodilator Agents; C025075:KWD 2131; D006632:Histamine; D013726:Terbutaline