The oedema disk technique was used to study the effects of orally admi
nistered H-1-receptor antagonists (cetirizine, chloropyramine, clemast
ine, cyproheptadine, dimethindene, loratadine, mequitazine and terfena
dine) on the inflammation induced with capsaicin or croton oil in the
mouse ear, and the effect of topically applied dimethindene maleate ge
l on the inflammation induced with croton oil in the mouse ear. In rat
s of the Wistar strain, oedema was induced in the hind paw by the subp
lantar injection of dextran or compound 48/80. Preliminary antihistami
ne treatment inhibited the development of oedema in the mouse ear, and
of oedema in the rat paw, to statistically significant extents, in a
dose-dependent manner. In all experiments, the most potent drugs were
loratadine and cyproheptadine.