[Anti-allergic properties of dimebon, fencarol and ketotifen in sensitization by common ragweed pollen].

It has been shown in experiments on guinea-pigs sensitized with ragweed pollen (Ambrosia artemisiifolia) that dimebon (9-/2-(2-methylpyridyl-5) ethyl/3,6- dimethyl-1, 2, 3, 4-tetrahydro-gamma-carboline dihydrochloride), a new antihistaminic drug, exerts a marked antianaphylactic effect which compares very favourably with that of phencarol. When administered in the minimal effective doses, dimebon is less active than ketotifen, whereas in doses of 2.5 and 5 mg/kg it, is more effective. Marked anaphylactic activity of the drug is accounted for by its antihistaminic and antiserotonin actions. When administered intragastrically, subcutaneously and intravenously, dimebon is less toxic than phencarol (by 1.28, 1.78 and 1.43 times, respectively) and ketotifen (by 1.78, 1.68 and 5 times, respectively).