Di Mascio, A., Heninger, G. & Klerman, G.L. Psychopharmacologia (1964) 5: 361. doi:10.1007/BF00441447
The effects of imipramine and desipramine were each examined at three dose levels in normal males. A placebo-controlled, double-blind procedure was employed. Effects were measured in a variety of behavioral and subjective responses. The resulting drug-action profiles reveal that imipramine produced hypnotic-like actions, as evidenced by the observation — and subjective reports — of marked sleepiness and concomitant impairment of intelectual and visuo-motor functioning. Side-effects of a cardiovascular, gastrointestinal disturbing, or anticholinergiclike nature were often experienced.
In contrast, desipramine produced effects in only two of the areas measured — a slight increase in sleepiness and a rise in pulse rate. The increased sleepiness was not accompanied by self-reports of a generalized impairment of performance, nor by actual decrements in performance measures. The side-effects reported were few in number and minimal in degree.
For both drugs the effects were dose related, maximal 2 1/2 hours after ingestion, and had subsided within 7 hours. The relationship of these effects to chemostructural variations, to clinical applications, and to possible modes of action of the two drugs were discussed.