(ĕn-ăk′tō-jĕn) [Gr. en, within, + L. tactus, touch, + Gr. gennan, to produce] Any psychoactive drug similar in chemical structure to MDMA, the recreational drug also known as ecstasy. Members of this drug class are derived from 1-(1,3-benzodioxol-5-yl)-2-butanamine.