Piscidia. Piscidia erythrina. Jamaica dogwood.

Piscidia. Piscidia Erythrina L, Jamaica Dogwood. Dogwood Bark. Ecorce du Bois de chien. Ecarce de Piscidie. Mulungu. Murungu.—This is a leguminous tree growing throughout the West Indies and the neighboring countries, being found in Florida, Texas, Mexico, and the northern portion of South America, and yielding to commerce a very valuable wood. From time immemorial the bark has been used for catching fish. The leaves, twigs, and root bark are collected, macerated with the residue from the distillation of rum or with lime water, then transferred into baskets, and the latter dragged up and down the water until the fish are stupefied.

In 1844 William Hamilton called the attention of the profession to the plant (P. J., Aug., 1844) as a powerful narcotic and analgesic. The bark of commerce is in pieces of 5 to 10 cm. in length and about 8 cm. in width, having a thickness of 1.5 cm. The outer surface of some of the pieces is of a dark gray-brown, while others are of a yellow-brown, with no shade of gray present. The bark is frequently studded with flattened protuberances of a lighter color than the surrounding cork. The central part of the bark is much lighter colored, and, when wet or freshly broken, is of a peculiar blue-green color. The inner part of the bark is of a dark brown color and very fibrous. It has a strong odor resembling opium when broken into pieces. It is acrimonious, and produces a burning sensation in the mouth and pharynx.

E. Hart obtained a neutral principle, C₂₉H₂₄O₈, to which he gave the name piscidin. (A. J. P., 1883, 369; see also Ibid., Sept., 1898.) Paul C. Freer and A. M. Clover have examined Hart's piscidin and found it to consist of two distinct chemical compounds. The first of these forms colorless, highly refracting rectangular prisms, melting at 201° C. (393.8° F.); composition C₂₅H₂₀O₇ . The second separates from alcohol in fine yellow needles, melting at 216° C. (420.8° F.); composition C₂₀H₁₈O₆. The authors found also in the aqueous extract of the bark piscidic acid, soluble in water; insoluble in chloroform, benzene or ligroin. It forms acicular crystals, which melt at 182° to 185° C. (359.6°-365.0° F.); composition H₂.C₁₁H₁₀O₇ . (A. Pharm., Feb., 1901.)

The action of the drug upon the lower animals has been studied by J. Ott and A. C. Nagle with similar results. (Jamaica Dogwood, Parke, Davis & Co., 1881.) The conclusions reached are,

1. It is narcotic to frogs, rabbits, and men.
2. It does not affect the irritability of the motor nerves.
3. It does not attack the peripheral ends of the sensory nerves.
4. It reduces reflex action by a stimulant action on the centers of Setschenow.
5. It produces a tetanoid state by a stimulant action on the spinal cord, and not by a paralysis of Setschenow's centers.
6. It dilates the pupil, which dilatation passes into a state of contraction upon the supervention of asphyxia.
7. It is a salivator.
8. It increases the secretion of the skin.
9. It reduces the frequency of the pulse.
10. It increases arterial tension by stimulation of the vasomotor center.
11. This increase of pressure is soon succeeded by a fall, due to a weakening of the heart itself.

The exact practical value of the drug has not been determined, nor are the results produced in man, by doses approaching toxic, known. Hamilton took a drachm, when suffering with severe toothache, on going to bed. He first felt a violent sensation of heat internally, which gradually extended to the surface, and was followed by profuse perspiration, with profound sleep for twelve hours. On awaking, he was quite free from pain, and without the unpleasant sensations which follow a dose of opium. Various practitioners have reported good results from its use as an anodyne in neuralgia, nervous insomnia, whooping cough, etc., but in other hands it has failed to do good. H. C. Wood found it in one case of neuralgia to produce great nausea and gastric distress without evincing the slightest narcotic effect. (For formula for fluidextract by Lemberger, see U. S. D., 19th ed., p. 1616; also D. C., 1881, 179.) The dose of the fluidextract is a fluidrachm (3.75 mils), to be carefully increased.

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.