[Pharmacology of astemizole (Hismanal) a non-sedating H1 antihistaminic].

In the compound 48/80 lethality test in rats, which is based on the specific activation of mast cells, astemizole was found to be a potent, long-acting and orally very effective inhibitor of anaphylactoid shock. In comparison to other histamine-H1 antagonists, astemizole was remarkably free of interactions with muscarine, serotonin, dopamine, noradrenaline and opiate receptors, and devoid of effects on normal body functions. No evidence of central effects was found, and astemizole did not change the intensity of action of several centrally acting drugs. Toxicity studies have shown astemizole to be a very safe drug. Astemizole is a very effective inhibitor of allergic reactions in rats and dogs. The low oral therapeutic doses of astemizole are expected to provide a pronounced and long-lasting inhibition of allergic reactions in the absence of side effects.