Barii Chloridum

Chloride of barium. Occurs in colorless, translucent tablets. It is soluble in diluted alcohol, and freely and entirely soluble in water. Dose, gr. 1/10—gr. ss.

Barii Dioxidum

Barium dioxide. A heavy, grayish-white or pale yellowish-white, amorphous, coarse powder. Almost insoluble in cold water. Hydrochloric and phosphoric acids decompose it, forming corresponding barium salts with hydrogen dioxide in solution.

Antagonists and Incompatibles

Sulphates, phosphates, and carbonates, and most of the salts of organic acids, are incompatible with it. Nitrate of silver decomposes it. The sulphates are ready antidotes, as sulphates of magnesium or sodium.

Synergists

The alkalies, and metallic salts from the therapeutical stand-point, increase its action on the retrograde metamorphosis. Ergot and digitalis favor its influence over the sympathetic system.

Physiological Actions

The soluble salts of barium have a disagreeable, bitter, and astringent taste. In a full medicinal dose irritation of the stomach is caused, and a sense of heat and burning is developed at the epigastrium. In one case (Ferguson) symptoms of poisoning came on in a week, produced by one twelfth of a grain of chloride of barium, administered three times a day, the whole amount taken being two and a half grains. The symptoms were extreme exhaustion and nervousness. An idiosyncrasy must have existed here, as so small an amount would not, under ordinary circumstances, have produced such decided effects. The usual symptoms in cases of poisoning are intense anguish, free salivation, great thirst, loss of voice, violent vomiting and purging, dilated pupils, frequent micturition, respiration slow and labored, pulse slow, increasing weakness, and finally complete paralysis of the extremities. The intelligence is preserved until near the end, when convulsions and coma come on. The post-mortem rigidity is very decided. There are present very considerable bronchial effusion and hyperaemia of the lungs, the heart is distended with black blood, and the brain is engorged. The stomach presents the usual appearances; there is intense hyperaemia, and sometimes perforation of this organ. The quantity necessary to cause death varies greatly—two and a half grains have brought on serious symptoms, and half a teacupful of the carbonate has been recovered from. One drachm of the chloride has caused death in seventeen hours, and one ounce of the same salt in one hour (Woodman and Tidy).

The effects on animals have been studied by Onsum, Cyon, Böhm, and myself (unpublished). Onsum held that the symptoms produced by the soluble salts of barium, when injected into the blood, were due to the formation of the insoluble sulphate. Cyon criticises this view, and shows that it is incorrect. The most elaborate, as it is the most recent, account of the physiological effects of the barium salts is that of Bohm. The statement to follow is based on this paper chiefly, and on the author's personal researches. In frogs, after injection of the chloride into the lymph-sac, extension and rigidity of the voluntary muscles ensued, followed by relaxation and paresis. The belly becomes distended and the intestines are thrown into active movements; the mouth is held wide open and a watery fluid continually escapes, while from the skin a mucus-like secretion exudes. When given to warmblooded animals by the stomach, profuse secretion takes place, active peristalsis of the bowels and copious alvine discharges, and free urination follow, but not until about a half-hour after the ingestion of the poison. If thrown into the veins the same symptoms arise immediately: in either case the tonic and clonic convulsions followed by paralysis occur; the pupils dilate; the heart is slowed, but its contraction is more energetic; the tension increases enormously in the arterial system after a preliminary fall, and finally insensibility and coma terminate the action. Very large doses, suddenly precipitated on the heart by injection into the jugular vein, will induce paralysis both of the heart and lungs. With the peripheral paralysis labored breathing ensues, due to paresis of the respiratory muscles, and death is caused rather by this than by cessation of the heart's action, when the poison is introduced subcutaneously. The paralysis in animals begins in the hind extremities. This paralysis is preceded by fibrillary trembling and clonic spasms mixed with tonic rigidity. The muscular contractility is entirely abolished when the paralysis is complete. On the nervous system of organic life barium chloride acts as a stimulant. The strong cardiac contractions, the dilated pupil, the energetic peristalsis of the bowels, the closure of the lumen of the intestines and also of the bladder, and the almost complete approximation of the peripheral vessel-walls, are the proofs of this excitation.

Therapy

Influenced by the observations of Böhm, Dr. Flint, of Leeds, England, has employed the chloride of barium successfully in the treatment of aneurism. The case was one of abdominal aneurism, in a woman of sixty-five. Tufnell's treatment had been carried out faithfully for five months without success, and iodide of potassium, for some unexplained reason, could not be taken. Chloride of barium was, after careful consideration, selected, and one fifth of a grain three times a day was administered three or four weeks, when it was increased to two fifths. The curative effect was very manifest, for after nearly five months of continued use of the same remedy the tumor was so reduced that it could be scarcely felt. Several similar cases have since been reported. Chloride of barium has proved very useful in hemorrhage, in acute congestion of organs, in atony of the intestines with deficient secretions, in atony of the bladder, in weakness of the heart with low arterial tension, in effecting removal of inflammatory exudates, etc. In the last-mentioned condition, especially, has the author used chloride of barium with excellent effect.