Abstract
An approach to the evaluation of antihistaminic preparations were studied by quantitative measurement of the inhibitory action of histamine skin response in intact dogs. The size of the papule, which was produced by subsequent intracutaneous injection of histamine in the foreleg of dogs, was quantitatively measured without any intravenous injection of dye. The inhibition of histamine skin response was proportional to the increase of the dose of chlorpheniramine maleate and of clemastine fumarate which were given orally. The linear regression between the logarithmic dose and the tested area was highly significant in both cases. Clemastine was approximately five times more effective than chlorpheniramine when analyzed by the parallel line assay of the dose response relationship. The intensity and the duration of the inhibitory effect of clemastine tablets were compared with those of chlorpheniramine tablets following oral administration and it was found that the effects of the former was stronger and longer than the effects of the later. From these observations, it is concluded that this method seems to be useful for the evaluation of the effects of oral antihistaminic preparations during preclinical test.