n. a tricyclic antidepressant and the principal metabolic product of the demethylation of imipramine in the liver. Desipramine is a stronger inhibitor of norepinephrine reuptake than of serotonin reuptake relative to imipramine. In general, it is less sedating and has fewer anticholinergic effects than imipramine and was frequently used to treat behavior disorders and insomnia in children. However, like all tricyclic antidepressants, it has fallen into relative disuse as safer medications have become available. U.S. trade name: Norpramin.