SODIUM N-METHYL-CYCLOHEXENYL-METHYL-BAR BITURIC ACID (EVIPAL) : HYPNOSIS, ANESTHESIA AND TOXICITY

The sodium salt of N-methyl-cyclohexenyl-methyl-malonyl urea (evipal) is one of the most interesting of the newer barbituric acid compounds. While it exhibits a rapid and high hypnotic coefficient and a very short duration of action, its toxicity, provided that it is properly administered, is considerably lower than that of the so-called short-acting barbiturates, e.g., nem butal, pernocton, and amytal. In these respects evipal bears closer resemblance to diethylepoxy-propionamide, diethylepoxy methylpropionamide and other epoxy amides being elaborated by Fourneau, Billeter and Bovet (1) than it does to the better known and more widely employed barbiturates. The enormous amount of literature appearing in recent months indicates that evipal has gained considerable popularity as a gen eral anesthetic in surgical procedures of short duration. This popularity is due to its wide margin of safety, speed of induction, good relaxation, minimal disturbance of circulation, short dura tion and negligible after-effects. However, very little work has been reported from the laboratories. Because of this paucity of basic data we deemed it expedient to subject this new barbiturate to certain pharmacological tests. The present report is limited to data obtained in studies of the hypnotic, the anesthetic, and the toxic action of evipal on rats and rabbits. TECHNIQUE With the exception of one series of 10 rats, treated subcu taneously for the purpose of determining the differential absor