[Therapy of urticaria with H1 and H2 antihistaminics. Results of clinical and experimental studies].

The antipruritic effect of modern H1- and H2-receptor blockers in chronic urticaria, that had been clinically proved, was experimentally studied by means of the histamine weal test. The H2-antihistamine preparation ranidine alone did not clearly reduce weals or erythemas induced by histamine when compared with a placebo. As expected, both parameters were markedly reduced by the H1-antihistamine preparation terfenadine. After combined administration of both drugs, the effect of the H1-blocker proved to be significantly increased. We discuss the possible mode of action and the consequences for anti-allergic therapy.