134 STIMULANTS TO CENTRAL NERVOUS SYSTEM 



Constituents. Hydrastis contains hydrastine, colorless and 

 slightly bitter, herberine, yellow and very bitter; canadin in small 

 amounts and hydrastinine, an artificial alkaloid having a marked 

 effect upon blood pressure. The action of the drug is represented 

 by hydrastine. Berberine is but a simple bitter in ordinary doses 

 but depresses the vasomotor center in large doses and lowers blood 

 pressure. Canadin has a morphine-like action but exists in too 

 small amounts to be of any therapeutic importance. 



Preparations and Doses. 



Tindura Hydrastis. H. §j — ij ; 30 — 60. D. 3ss — ij ; 2 — 



8. 

 Fluidextradum Hydrastis. H. 3ij— viij ; 8. — 30. D. TTL v 



— Ix ; .032—4. 

 *Fluid Hydrastis. For application only. 

 Glyceriium Hydrastis. For application only. 100 per cent. 



Hydrastis. 

 Hydrastine, a variable mixture. H. grs. xv — xxx; 1. — 2. 



D. gr. 1/5—% ; 0.010—0.03. 

 Hydrastininw Hydrochloridium. H. gr. j — ij ; 0.065 — 0.13. 



D. gr. yi2—y2; 0.005—0.03. 



Externally and Locally. Hydrastis has a slight astringent 

 action and is therefore employed as a stimulant to mucous mem- 

 branes in chronic catarrhal conditions. 



Nervous System. Moderate doses resemble the action of 

 strychnine in many respects, particularly upon the cord. The 

 cord is stimulated, reflexes increased with tonic and clonic convul- 

 sions, but the paralytic stage is more prominent. 



Digestive System. It has the action of a bitter upon the appe- 

 tite. It stimulates the secretion and motion of the stomach and in- 

 creases peristalsis in the intestines. Large doses produce vomiting 

 and diarrhea. 



Respiratory System. In ordinary doses the respiratory cen- 

 ter is stimulated; but in poisoning it is depressed, and death takes 

 place from asphyxia due to paralysis of the respiratory center or to 

 convulsions, very similar to the case in strychnine poisoning. 



Circulatory System. Large doses stimulate the vasomotor cen- 

 ter, constrict the arterioles and raise blood pressure. This action 

 is soon followed by a lowered blood pressure, due to depression of 

 the above center and the heart. There is so much contradictory 

 evidence relative to the action of the drug upon the circulation that 

 it seems best to say that medicinal doses produce a short and weak 

 rise in blood pressure if any at all, and that this is soon followed, by 

 a depression as explained above. 



Uterus. Hydrastine is a feeble oxytoxic, acting similarly to, 

 but less active than, ergot. 



