Source, Etc

Under the name of curare several (at least three) varieties of a dark, extract-like mass appear in commerce. They are all arrow poisons prepared by tribes of Indians in the valleys of the Amazon and Orinoco and their tributaries. The manner in which these extracts are prepared, and the ingredients, vegetable or animal, that enter into them are only imperfectly known. The bark of various species of Strychnos (S. toxifera, Bentham; S. Castelnoei, Weddel; S. Gubleri, G. Planchon, S. Crevauxii, G. Planchon, etc.) appear to be essential constituents. In the bark of these plants considerable quantities of poisonous alkaloids are present.

Description

Curare has been imported in gourds, in small earthen pots, and in bamboo tubes, but gourd curare is now no longer a commercial article. It has the appearance of a very dark brown or nearly black extract resembling black catechu, often containing small cavities. That imported in bamboo is dark brown and granular, the broken fragments frequently exhibiting crystals sufficiently large to be visible to the naked eye. It has little or no odour, but a very bitter taste.

All these varieties of curare are poisonous when injected subcutaneously, but when administered by the mouth they are harmless, producing, it is said, the effect of a stomachic tonic. The degree of toxicity varies not only in the different varieties but in different specimens of the same variety, and the strength, therefore, of each parcel must be determined before it can be used medicinally. Bamboo curare yields to water about 84 to 88 per cent., gourd curare 34 to 75 per cent., pot curare 50 to 87 per cent. (Bohm, 1898). These figures suffice to show the extreme variability of the drug.

Constituents

Gourd curare contains the alkaloids curarine and curine; curarine is extremely toxic, but curine is less so. Bamboo curare contains tubocurarine and curine. Pot curare contains protocurarine, protocurine, and protocuridine. Urarine has also been reported; it is said to possess the typical curare action.

Uses

Curare has been employed as a remedy for hydrophobia and chorea; it has also been found useful for tetanus, but it would appear desirable to abandon the use of the crude drug in favour of that of its active alkaloids.