In a double-blind crossover study, the wheal inhibiting effect of a new beta-agonist,
KWD 2131, and
terbutaline was evaluated. The substances were given intracutaneously in five different concentrations, each together with specific
allergen or with
histamine. During the 2 days' study, 10 patients with known type I-
allergy in the skin were randomly assigned to the
KWD 2131 or
terbutaline group. Both substances gave a dose-dependent inhibition of the
allergen-induced wheals. They were, in this respect, equipotent. The greatest protective effect was obtained with the highest doses of both substances (250 micrograms
KWD 2131; 25 micrograms
terbutaline). In these doses, the inhibition with
KWD 2131 and
terbutaline was 55 and 45%, respectively (P less than 0.001). Significant inhibition was also seen with the two following lower doses of both substances i.e. 100 and 25 micrograms
KWD 2131 and 10 and 2.5 micrograms
terbutaline (P less than 0.001-0.01).
KWD 2131 and
terbutaline did not show any dose-dependent inhibition of
histamine-induced wheals. Statistically significant protection against
histamine was only reached with the highest dose
KWD 2131 (250 micrograms) (P less than 0.05). We conclude that the inhibitory effect of
KWD 2131 and of
terbutaline on
allergen-induced wheal formation in the dose-range tested, is of a selected
anti-allergic quality.