Colchicum is one of the most valuable remedies in the urie-acid diathesis, and the prejudice against it is absurd; and, far from it being a vascular depressant, it often gives strength and regularity to a feeble and irregular pulse, especially in chronic gout with acute exacerbations. Burney Ye° (Brit. Med. Jour., Jan. 7, 'SS).
One of the very good reasons why it has failed in many hands is that it is generally given in purgative doses, which prevents its specific effects upon the cir culation. In acute rheumatism or gout the circulation should be reduced with aconite or veratrum before giving col chicum. Goss ("Mat. Med., Phan, and Special Ther.," '89).
In small therapeutic doses produces gastro-intestinal disturbances, the symp toms differing in degree only from those of poisoning. Before they come on, however, there is a lowering of the pnIse rate, sometimes as much as twelve beats per minute. Upon the skin it acts oc casionally, producing, in some cases, diaphoresis, and, it is believed, the amount of this action is in inverse ratio to the effect upon the bowels. Any nervous symptoms, such as vertigo, headache, and muscular weakness, which may be present as the result of the colchicum, are probably sympathetic upon the gastro-intestinal irritation. It is evident that the drug influences the bowels powerfully, and probably in this way acts as an eliminative. But, with the minute doses often used with advan tage in the disease, purging does not occur, and consequently increased elim ination, if it takes place, must be through the kidneys; great interest, therefore, attaches to the influence of the remedy upon the urinary secretion. In considering this the effects of poisonous and therapeutic doses must not be con founded, for it is very evident that an irritation which causes suppression of urine inay, when present in a much milder degree, produce an increased flow. When the drug purges freely it is very probable that elimination by the kid neys is lessened; and no account of this is taken by any of the observers \vho have studied its effect in the elim ination of urea and uric acid; all con tent themselves with noting the propor tion of urea and uric acid in the urine, when it is evident that the mere pro portion, unchecked by the absolute amount of urine excreted in the twenty four hours, is no criterion as to the absolute amount eliminated. H. C.
Wood ("Therapeutics: Its Principles and Practice,'"94).
By some observers it is stated that there is au increased elimination both of urea and uric acid, while by others it is denied. It is possible that dif ference in dietary of the patients may account for this discrepancy. Murrell ("Manual of Materia Medica and Thera peutics,'"96).
Full medicinal or larger doses produce great depression of the circulation, with a small, rapid, and thready pulse. The marked cardiac depression and collapse which occur when poisonous do6es have been taken are more the result of the severe gastro-enteritis than of any direct action upon the heart. The nervons system is unaffected by medicinal doses; but large or poisonous doses may induce cerebral excitement. Large doses render the respiratory movements slow and shallow. Personal experiments are suf ficient to satisfy the author that the excretion of urea and uric acid by the kidneys is considerably heightened un der medicinal doses. Butler ("Text-book of Mat. Med., Pharm., and Ther.," '96).
Colchicum induces fall of temperature during the period of emetocatharsis; when injected into dogs there is a marked fall in blood-pressure. The a.mount of urea and uric acid excreted in the urine is much increased by the drug; Lewius found the urea excreted to be almost doubled in amount. Biddle ("Mat. Med. and Then," '96).
The most discordant statements have been made about the action of colchicum upon the renal secretion, but it has not been definitely shown that either the quantity or composition is altered. After death by poisoning, the alkaloid is found in the blood and in most of the organs of the body. Hale White ("Mat. -Med., Phan, and Tiler.," '96).
Though the physiological effects of this drug are very similar to tbose of veratrum, yet one cannot be ally substituted for the other. It duces much irritation of the fauces, with increase of saliva. It irritates the di gestive tract and produces these effects whether taken into the stomach or in jected into the veins. In large doses it considerably increases biliary secretion, and at the same time purges powerfully.