Gelsemium

Yellow Jasmine

Yellow jasmine. The rhizoma and roots of Gelsemium sempervirens (Linné) Persoon (Nat. Ord. Loganiaceae).

Extractum Gelsemii Fluidum

Fluid extract of gelsemium. Dose,

τη ij—τη x.

Tinctura Gelsemii

Tincture of gelsemium. Dose, τη v—τη xx.

The so-called gelseminine is obtained by evaporation of the tincture, and is a very uncertain preparation; the dose is gr. ss—gr. ij. It is only used by the eclectic practitioners.

Disappointment is frequently experienced from the use of gelsemium preparations, owing to the fact that they are made from the dried root. In the process of drying, even spontaneously, the alkaloid disappears. The most trustworthy preparations are the official, prepared conscientiously from the fresh root.

Composition

Gelsemium contains a very powerful alkaloid—gel-semine or gelsemina—and gelsemic or gelseminic acid, by some said to be identical with aesculin; but Wormley has shown the fallacy in the evidence on which this statement was based, and Fredigke's account of gelsemic acid agrees with Wormley's in all essential particulars. It contains also an acrid resin, volatile oil, gallic acid, a yellow coloring-matter, besides some other unimportant ingredients.

Gelsemine

In its pure state gelsemine (gelsemia) is a colorless, odorless solid, having an intensely persistent, bitter taste. It has strongly basic properties, completely neutralizing the most powerful acids, forming salts of which the sulphate, nitrate, chloride, and acetate are freely soluble in water (Wormley). Dose, gr. 1/60—gr. 1/20.

Antagonists and Incompatibles

The caustic alkalies and tannic acid are chemically incompatible. As respects the physiological actions, gelsemium is antagonized by the diffusible stimulants, by alcohol, ammonia, opium, digitalis, etc. The lethal effects are best treated by emetics, warmth, alcoholic stimulants, by faradization and artificial respiration, by morphine subcutaneously, and, according to Fredigke, by the tincture of xanthoxylum fraxineum.

Synergists

Conium, physostigma, tobacco, opium, etc., when administered with gelsemium, increase its effects in the whole sphere of its physiological activity.

Physiological Actions

The preparations of gelsemium have a bitter and somewhat aromatic taste, and a narcotic odor. They do not produce gastric irritation. The active substance, being crystalloidal, diffuses into the blood with facility. In moderate doses, but sufficient to produce decided physiological effects, gelsemium causes a feeling of languor and mental calm, slowing of the action of the heart, drooping of the eyelids, dilatation of the pupil, and some feebleness of muscular movements. In larger doses the physiological effects are as follows: vertigo, double vision, amblyopia, paralysis of the levator pal-pebrae so that the upper eyelid can not be raised, dilated pupil, labored respiration in consequence of a paretic state of the respiratory muscles, slow and feeble action of the heart, great muscular weakness, and sensibility to pain and touch much reduced. These effects are produced in about a half-hour after the stomach administration, and last two or three hours, when they subside. When lethal doses are taken, the above-described symptoms occur in a more intense degree. The gait is at first staggering, but the power of muscular movement soon ceases, and a sense of numbness diffuses over the body. The eyelids close (paralysis of the levator), the pupils dilate widely, vision is lost, and the pupils cease to respond to the stimulus of light. The lower jaw drops, and the power of speech is lost in consequence of paralysis of the muscles of the tongue. The respirations are labored, shallow, and irregular; the action of the heart weak, feeble, and intermittent. Generally the skin is covered with a profuse perspiration, but no other evacuation takes place. Death occurs from asphyxia, and the action of the heart ceases after the respiratory movements. Consciousness is preserved until near the close, and until carbonic poisoning ensues. In one instance (Wormley) extreme restlessness was noted, but generally there is a condition of calm, a soporose state, or the unconsciousness of carbonic-acid narcosis, and convulsions never occur.

The author's investigations have demonstrated that gelsemium is a paralyzer of motility and sensibility; that sensibility is first affected in cold-blooded animals (frogs), and afterward motility, and that in warmblooded animals the motility is affected before sensibility. As respects the seat of the action, the author has ascertained that the end-organs of the motor nerves, and the nerve-trunks, do not lose their irritability, and that the muscular contractility is unimpaired. "Its paralyzing effect is due to its action on the motor center, and not to an action on the peripheral nerve-fibers. It acts also on the sensory portion of the cord, producing at last complete anaesthesia; but this effect in warmblooded animals, and in man, is toxic only, and follows the paralysis of the motor functions." Applying the precise observations which are made on animals to the explanation of the lethal effects which have occurred in man, we are conducted to the following conclusions: the disorders of voluntary movement, and the more or less complete paralysis of the motor and of the sensory functions, are due to the effects of gelsemium on the motor and sensory portions of the cord, the functions of the sensory columns resisting longer the action of the poison. The labored respiration is due to the paretic state of the respiratory muscles, especially of the diaphragm. The depressed action of the heart is probably secondary to the diminished respiration movements, which produce this result by impeding the flow of blood through the pulmonary capillaries. The dilated pupil, the double vision, the ptosis, are due to paralysis of the third pair.

In rabbits and cats gelsemium, in lethal doses, affects motility in a very remarkable manner: when the paralyzing effects are becoming manifest—first in the fore extremities—these animals perform a series of backward movements, in which sometimes a complete backward somersault occurs. In pigeons, general muscular tremors precede the backward movements. No corresponding acts have taken place in the fatal cases observed in man. A very considerable reduction of temperature occurs from lethal doses in warm-blooded animals.

The author's experimental observations on the physiological actions of gelsemium have since been fully confirmed by Ott, by Ringer, and by O. Berger, in an elaborate series of investigations. The study of Ringer and Murrell is a model of a research of this kind.