1911 Encyclopædia Britannica/Colchicum

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COLCHICUM, the Meadow Saffron, or Autumn Crocus (Colchicum autumnale), a perennial plant of the natural order, Liliaceae, found wild in rich moist meadow-land in England and Ireland, in middle and southern Europe, and in the Swiss Alps. It has pale-purple flowers, rarely more than three in number; the perianth is funnel-shaped, and produced below into a long slender tube, in the upper part of which the six stamens are inserted. The ovary is three-celled, and lies at the bottom of this tube. The leaves are three or four in number, flat, lanceolate, erect and sheathing; and there is no stem. Propagation is by the formation of new corms from the parent corm, and by seeds. The latter are numerous, round, reddish-brown, and of the size of black mustard-seeds. The corm of the meadow-saffron attains its full size in June or early in July. A smaller corm is then formed from the old one, close to its root; and this in September and October produces the crocus-like flowers. In the succeeding January or February it sends up its leaves, together with the ovary, which perfects its seeds during the summer. The young corm, at first about the diameter of the flower-stalk, grows continuously, till in the following July it attains the size of a small apricot. The parent corm remains attached to the new one, and keeps its form and size till April in the third year of its existence, after which it decays. In some cases a single corm produces several new plants during its second spring by giving rise to immature corms.

C. autumnale and its numerous varieties as well as other species of the genus, are well known in cultivation, forming some of the most beautiful of autumn-flowering plants. They are very easy to cultivate and do not require lifting. The most suitable soil is a light, sandy loam enriched with well decomposed manure, in a rather moist situation. The corms should be planted not less than 3 in. deep. Propagation is effected by seed or increase of corms; the seed should be sown as soon as it is ripe in June or July.

Colchicum was known to the Greeks under the name of Κολχικόν, from Κολχίς, or Colchis, a country in which the plant grew; and it is described by Dioscorides as a poison. In the 17th century the corms were worn by some of the German peasantry as a charm against the plague. The drug was little used till 1763, when Baron Störck of Vienna introduced it for the treatment of dropsy. Its use in febrile diseases, at one time extensive, is now obsolete. As a specific for gout colchicum was early employed by the Arabs; and the preparation known as eau médicinale, much resorted to in the 18th century for the cure of gout, owes its therapeutic virtues to colchicum; but general attention was first directed by Sir Everard Home to the use of the drug in gout.

For medical purposes the corm should be collected in the early summer and, after the outer coat has been removed, should be sliced and dried at a temperature of 130° to 150° F.

The chief constituents of colchicum are two alkaloids, colchicine and veratrine. Colchicine is the active principle and may be given in full form in doses of 1/32 to 1/16 grain. It is a yellow, micro-crystalline powder, soluble in water, alcohol and chloroform, and forming readily decomposed salts with acids. It is the methyl ester of a neutral body colchicein, which may be obtained in white acicular crystals.

The official dose of powdered colchicum is 2 to 5 grains, which may be given in a cachet. The British Pharmacopoeia contains 1) an extract of the fresh corm, having doses of 1/4 to 1 grain, and (2) the Vinum Colchici, made by treating the dried corm with sherry and given in doses of 10 to 30 minims. This latter is the preparation still most generally used, though the presence of veratrine both in the corm and the seeds renders the use of colchicine itself theoretically preferable. The dried ripe seeds of this plant are also used in medicine. They are exceedingly hard and difficult to pulverize, odourless, bitter and readily confused with black mustard seeds. They contain a volatile oil which does not occur in the corm, and their proportion of colchicine is higher, for which reason the Tinctura Colchici Seminum—dose 5 to 15 minims—is preferable to the wine prepared from the corm. At present this otherwise excellent preparation is not standardized, but the suggestion has been made that it should be standardized to contain 0.1% of colchicine. The salicylate of colchicine is stable in water and may be given in doses of about one-thirtieth of a grain. It is often known as Colchi-Sal.

Pharmacology.—Colchicum or colchicine, when applied to the skin, acts as a powerful irritant, causing local pain and congestion. When inhaled, the powder causes violent sneezing, similar to that produced by veratrine itself, which is, as already stated, a constituent of the corm. Taken internally, colchicum or colchicine markedly increases the amount of bile poured into the alimentary canal, being amongst the most powerful of known cholagogues. Though this action doubtless contributes to its remarkable therapeutic power, it is very far from being an adequate explanation of the virtues of the drug in gout. In larger doses colchicum or colchicine acts as a most violent gastrointestinal irritant, causing terrible pain, colic, vomiting, diarrhoea, haemorrhage from the bowel, thirst and ultimately death from collapse. This is accelerated by a marked depressant action upon the heart, similar to that produced by veratrine and aconite. Large doses also depress the nervous system, weakening the anterior horns of grey matter in the spinal cord so as ultimately to cause complete paralysis, and also causing a partial insensibility of the cutaneous nerves of touch and pain. The action of colchicum or colchicine upon the kidneys has been minutely studied, and it is asserted on the one hand that the urinary solids are much diminished and, on the other hand, that they are markedly increased, the specific gravity of the secretion being much raised. These assertions, and the total inadequacy of the pharmacology of colchicum, as above detailed, to explain its specific therapeutic property, show that the secret of colchicum is as yet undiscovered.

The sole but extremely important use of this drug is as a specific for gout. It has an extraordinary power over the pain of acute gout; it lessens the severity and frequency of the attacks when given continuously between them, and it markedly controls such symptoms of gout as eczema, bronchitis and neuritis, whilst it is entirely inoperative against these conditions when they are not of gouty origin. Despite the general recognition of these facts, the pharmacology of colchicum has hitherto thrown no light on the pathology of gout, and the pathology of gout has thrown no light upon the manner in which colchicum exerts its unique influence upon this disease. Veratrine is useless in the treatment of gout. A further curious fact, doubtless of very great significance, but hitherto lacking interpretation, is that the administration of colchicum during an acute attack of gout may often hasten the oncoming of the next attack; and this property, familiar to many gouty patients, may not be affected by the administration of small doses after the attack. Altogether colchicum is a puzzle, and will remain so until the efficient poison of gout is isolated and defined. When that is done, colchicine may be found to exhibit a definite chemical interaction with this hitherto undiscovered substance.

In colchicum poisoning, empty the stomach, give white of egg, olive or salad oil, and water. Use hot bottles and stimulants, especially trying to counteract the cardiac depression by atropine, caffeine, strophanthin, &c.