144. DEPRESSANTS TO CENTRAL NERVOUS SYSTEM 



of morphine represents the action of opium. Furthermore, it is 

 suitable for hypodermic use and conseqiiently of more value when 

 rapid action is desired. Morphine is less liable to upset the diges- 

 tion than opium, but it is less useful to reduce the amount of sugar 

 in the urine in glycosuria. Opium is to be preferred for action 

 upon the digestive tract. 



DIACETYLMORPHINA — DIACETYLMORPHINE 



Synonyms. Heroina, Heroin 



This is the diacetyl ester of morphine. Heroin is a proprie- 

 tary preparation and much more expensive than the official drug. 

 Diacetylmorphine occurs as a white, odorless, crystalline powder, 

 slightly bitter and slightly alkaline in reaction. It is insoluble in 

 water but soluble in acidulated water. The hydrochloride (diacetyl- 

 morphinse hydrochloridum) is soluble in alcohol and water. 



Doses of the Alkaloid or Us Salt. 



H. gr. %— ij ; .032— .12. 



D. gr. y24— yi2; .0026— .005. 



Diacetylmorphine is not so marked a hypnotic or analgesic as 

 morphine but has a greater tendency to increase reflex excitability. 

 Like morphine it depresses the respiratory center and has been 

 considered by Dreser to have a more specific action in depressing 

 this center to reflex stimuli, as in cough, than to direct stimulation 

 as from carbon dioxide. He also stated that it slowed the respira- 

 tions but increased the force and depth of the inspirations. There 

 is, however, a considerable reduction in the amount of air respired 

 per unit of time. On account of its action upon the respiratory 

 tract, Dreser believed it particularly useful in cough, but Cushny 

 has more recently found that heroin affects the respirations, in man 

 at least, just the sam.e as morphine does. It seems therefore that 

 it has no advantage over the older drug. Another advantage claimed 

 for it is that there is less danger of producing toxic action since 

 there is a greater difl^erence between therapeutic and toxic doses 

 than in case of morphine, although the actual toxic dose is not much 

 different from that of morphine. This is because the therapeutic 

 dose is so correspondingly small. The hydrochloride of diacetyl- 

 morphine may be given in pill, syrup, aqueous solution per os. or 

 in aqueous solution hypodermically, but it is most often prescribed 

 in a syrup, of which there are several upon the market. 



Its chief and only use is to check cough and most impartial 

 investigators have generally failed to obtain any better results with 

 it than from the older drugs, morphine and codeine, and it is prob- 

 ably in no way superior to them. 



