THE PHARMACOLOGY OF ACETYLENE DIBROMIDE (s-DIBROMOETHYLENE)

¹ Department of Physiology and Pharmacology, University of Alberta, Edmonton, Alberta, Canada

The pathological findings in the alimentary canal together with the physical properties of the drug and its pronounced action on smooth muscle suggest a possible explanation for the aberrant reactions to the drug. After the intragastric administration of the drug one of three alternatives may occur, depending on the degree and rate of absorption. If the stomach is filled with food the drug may become mingled with the food mass and not be absorbed at all, thus giving rise to no reaction, or to a delayed response. If the drug is mixed with alcohol and placed in an empty stomach, there will be an immediate inhibition of peristaltic movements and a loss of muscular tone; it will fall to the most dependent portion of the stomach and remain there, exerting its irritant action on a small, localized area of mucosa. This will ulcerate and the drug will come in contact with the naked dilated vessels of the eroded area and enter directly into the circulation. This process would account for the acute response to the drug.

If the drug is suspended in acacia and placed in an empty stomach the conditions are established which will allow for the delayed response. The emollient action of the acacia is sufficient to delay the ulceration of the gastric mucosa which occurs when the drug is suspended in alcohol, but does not affect the inhibitory action of the drug on smooth muscle. The end result of this is to keep the substance in the stomach until such time as it erodes the mucosa and enters the general circulation.

Dibromoethylene narcotizes all tissues with which it comes in contact. In addition to this narcotic action it is a powerful irritant, particularly to epithelial structures and to mucous membranes with which it comes in direct contact. From the nature and the distribution of the pathological lesions in animals which have succumbed to fatal doses of the drug it may be inferred that after it is absorbed it is distributed throughout the entire body and that it is excreted mainly by the kidneys and partially by the lungs.