An extract of colchicum is officinal in Britain and France; and an acetic extract in Britain. The latter is the most active of all the pharmaceutical preparations of colchicum.
Lastly, an oxymel of colchicum is in use in Germany, France, and the Netherlands.
Quack and Patent Medicines.—In all specifics for gout the analyst will naturally search for colchicum. Most gout pills contain the extracts; and liquids, such as “Reynolds’ gout specific,” the wine or the tincture, variously flavoured and disguised.
The strength of the different pharmaceutical preparations may be ascertained by dissolving in chloroform, evaporating off the chloroform, dissolving in water (which is finally acidified by from 7 to 10 per cent. of sulphuric acid), and titrating with Mayer’s reagent (see [p. 263]). If the solution is diluted so that there is about one part of colchicine in 600 of the solution, then each c.c. of Mayer’s reagent equals 31·7 mgrms. colchicine.
§ 511. Fatal Dose.—In Taylor’s Principles of Medical Jurisprudence is mentioned an instance in which 31⁄2 drachms of colchicum wine, taken in divided doses, caused death on the fourth day. The quantity of the active principle in the colchicum wine, as found by Johannson (Dragendorff), being 0·18 per cent., it follows that 24·4 mgrms. (·378 grain) were fatal, though not given as one dose, so that this quantity may be considered as the least fatal one. Casper puts the lethal dose of colchicine at from 25 to 30 mgrms. (·385 to ·463 grain). It is, however, incontestable that there are cases of recovery from as much as 70 mgrms. (1·08 grain). The lethal dose of the pharmaceutical preparations of colchicum may, on these grounds, be predicted from their alkaloidal contents, and, since the latter is not constant, in any medico-legal inquiry, it may be necessary, where facility is given, to ascertain the strength of the preparation administered.
§ 512. Effects of Colchicine on Animals.—The researches of Rossbach show that the carnivoræ are more sensitive to colchicine than any other order of mammals. Frogs show a transitory excitement of the nervous system, then there is loss of sensation, paralysis of motion, and of the respiratory apparatus; the heart beats after the respiration has ceased. Death follows from paralysis of the respiration. The mucous membrane of the intestine is much congested and swollen.
I have seen cattle die from the effects of eating the meadow-saffron; the animals rapidly lose condition, suffer great abdominal pain, and are generally purged. The farmers, in certain parts of the country, have had extensive losses from want of care and knowledge with regard to colchicum poisoning.
§ 513. Effects of Colchicum on Man.—Colchicum poisoning in man[550] is not very common: 2 deaths (accidental) are recorded in England and Wales during the ten years ending 1892. F. A. Falck was able to collect from medical literature, prior to 1880, 55 cases, and he gives the following analysis of the cases:—In 2, colchicum was taken for suicidal purposes; of the unintentional poisonings, 5 were from too large a medicinal dose of colchicum wine, syrup, or extract, given in cases of rheumatism; in 13 cases, colchicum was used as a purgative; 42 cases were owing to mistaking different preparations for drinks, or cordials—the tincture in 5, and the wine in 14, being taken instead of orange tincture, quinine wine, schnapps or Madeira; in 1 case the corms were added to mulled wine, in another, the leaves consumed with salad; in 16 cases (all children), the seeds of colchicum were eaten. Forty-six of the 55 died—that is, 83·7 per cent.
[550] For the curious epidemic of diarrhœa which broke out in the Rhone Gorge in 1785, and was referred to colchicine, see “Foods,” p. 287.