HEROIN constitutes another deriv ative. If acetyl groups are substituted for the two hydroxyl of mor phine, heroin is produced. Its sedative action on the respiration is said to be more powerful than that of morphine and codeine. The fatal dose of heroin is 100 times the efficacious dose, while the fatal dose of codeine is only 10 times the efficacious dose. Heroin has very little convulsive action.
Peron in is a preparation of which the cardio-depressant effects arc so marked as to exclude its use, inasmuch as its therapeutic value is not superior to that of codeine or of dionin. Dionin and codeine, on the other hand, are drugs which represent a permanent addition to the armamentarium. Dionin is in some respects preferable to codeine. It is more soluble, and used hypodermically is painless. It does not produce the euphoria so charaeteritic of morphine, and, in a less degree. of codeine. Hence there is far less ]anger of habit-forma tion. The narcotic effects are also less pronounced in case of dionin than in any of the other drugs of the group studied.
Thus, as an anodyne and as a soporific dionin is of vastly inferior importance. nil the other hand. it seems to exercise a specific and action upon the sensory terminations in the trachea and bronchi. It controls all forms of irritative and superfluous cough; it reg ulates respiration; it diminishes the feeling of dyspnwa. In other words. it fulfills the same indications as does codeine. but produces less of the psy chical effects of that drug. The proper ties of heroin place it midway between dionin and codeine, on the one hand, and morphine, on the other. A powerful respiratory sedative, it produces at the same time a considerable degree of euphoria and of somnolence. It has a well-marked depressant action upon the heart and the vasomotor system. The practitioner has thus at his command a set of alkaloids which produce a graded series of effects of a very definite char acter. Mayor (Revue Med. de la Suisse ROM, March, 190C).