In the course of investigation of many different steroids Selye1 noted in 1941 that certain of these substances produced varying degrees of depression and anesthesia in laboratory animals. This was only of academic interest until recently when Laubach and associates2 studied a large number of new water-soluble steroids to determine their anesthetic activity. Of the substances tested, it was found that 21-hydroxypregnanedione sodium succinate (see figure) was the most promising. The compound was studied for its possible undesirable side-effects on animals, and its therapeutic index was established. This drug was found capable of anesthetizing laboratory animals with a wide margin of safety. In anesthetic doses it did not produce significant hormonal effects and did not cause salt retention or damage to any vital organ.3 Gordan and associates4 studied the effects of this compound, known as Viadril, on the cerebral metabolism of humans and reported metabolic changes