ANTI-DEMENTIAL AGENT

PURPOSE:To provide a safe anti-demential agent exhibiting improving effect generally to demential syndrome by various estimation methods, by using DL- or L-threo-3,4-dihydroxyphenylserine as an active component acting as a norepinephrine precursor. CONSTITUTION:The objective anti-demential agent contains DL- or L-threo-3,4- dihydroxyphenylserine (abbreviated as threo-DOPS) as an active component. Threo-DOPS exhibits improving effect in plural estimation tests such as Hasegawa's scale, N-type mentation test, corresponding word-pair mneme test, etc., and is judged to be effective to demential syndrome in general. The activity of L-isomer is about twice as high as the activity of DL-isomer. The combined effect with a peripheral decarboxylase inhibiting agent is not so high as in the case of L-dopa. No particular side-effect has been found in investigation and the compound is useful as an anti-demential agent.