Source and Composition. The corms and seeds of Colchicum autumnale (nat. ord. Liliaceae). It contains an intensely bitter and poisonous alkaloid, Colchicine, which is converted by acids into Colchiceïn and a resin, also tannic and gallic acids, etc.
Preparations. Those of the seeds are the most reliable.
- Vinum Colchici Seminis, Wine of Colchicum-seed,—Dose, ♏x-xxx. This wine has a drug-strength of only 15 per cent., while the next has 40 per cent., and still this is the most reliable of the two.
- Vinum Colchici Radicis, Wine of Colchicum-root,—Dose, ♏v-xv-xxx.
- Extr. Colchici Sem. Fl., ♏j-v.
- Extr. Colchici Rad. Fl., ♏v-xx.
- Tinctura Colchici Seminis, ♏v-xx.
- Colchicina, Colchicine,—gr. 1/120-1/60.
Physiological Action. Colchicum is a drastic purgative, emetic, diuretic, diaphoretic, a gastro-intestinal irritant, and a cardiac depressant. Its taste is bitter and acrid. In small doses it increases secretion, especially the urine and the perspiration. In full doses its action is emeto-cathartic, producing profuse watery discharges, great nausea, and muscular feebleness. In large doses it is a powerful gastro-intestinal irritant, causing griping, choleraic discharges, lowered arterial tension, and depression of the heart by reflex action over the distribution of the pneumogastric. Then great prostration, convulsions and collapse, death from exhaustion, with consciousness preserved until carbonic acid narcosis sets in. On the excretion of uric acid and urea its influence is a greatly disputed question; but it probably increases the flow of bile.
Treatment of Colchicum Poisoning. Emesis and catharsis. Warm drinks freely. Tannic Acid as an antidote. Morphine hypodermically, to sustain the heart, also Alcohol.
- Therapeutics. Colchicum is a specific palliative in—
- Acute Gout, in which it should be given with an alkali, and kept short of emeto-catharsis. It does not prevent relapses, and its power is weakened by repetition in this disorder. The alkaloid is probably the most effective preparation in this disease, given in granule of gr. 1/60, four times daily.
- Ascites, due to obstructive disease of the liver,—Colchicum in full doses, with Opium to sustain the heart, is effective, from the drain which it establishes.
- Portal Congestions,—are relieved by Colchicum given with a saline purgative, as it markedly depletes the portal circulation.
- Cerebral Congestion of acute type,—Colchicum as a revulsive purgative.
- Acute Rheumatism,—Colchicum is often very efficient, but frequently fails, and at any rate should not be long administered in this affection.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.