This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
A certain amount of potash salt is essential, as we have seen, for the proper constitution and action of the corpuscles, and the chloride seems to be the best suited for this purpose (Rabuteau); but the prolonged use of the remedy in any combination has an unfavorable effect. Loffler has reported the results in five of his students who took doses of from 1 to 5 dr. of alkaline carbonates for several days, and then allowed blood to be taken from a vein. It was found to be like "cherry juice" in color and density, the red corpuscles were paler, and the white ones more numerous than normal; there was excess of water and of fatty material, and the clot was less firm and elastic than it ought to be (Schmidt's Jahrb., 1848). A curious illustration of the diminished coagulating power of the blood under the influence of nitrate of potash is furnished by Dr. Stevens, who had occasion to bleed a man who had lately taken an ounce of that salt, and was surprised to find the venous blood red, and not at all coagulable (Lancet, ii., 1862, quoted by Dr. Basham). In animals, after injection of nitrate, the result is similar (Rabuteau).
Martin Solon, having analyzed blood drawn from the vein of a robust man suffering from acute rheumatism, and treated by nitre, found the fibrine diminished, though the inflammatory process was still at its height; ten days afterward, when the remedy was no longer being taken, the blood-clot was dense and buffed (Bulletin de Therapeutique, 1843). That the drug cannot, however, be depended upon for antagonizing the effects of disease is shown by the fact of fibrinous deposits having been found on the heart-valves in patients dying during its free administration (Medical Times, i., 1863).
Both this salt and the chlorate have the power of rendering venous blood bright red, and much stress was laid upon this change by the early advocates of the direct oxygenation theory (Stevens, O'Shaughnessy: Lancet, ii., 1831), but Isambert, after making fresh experiments, asserts that their statements on this point are incorrect (Gazette Med., 1874), and although the change does occur, it varies with physical conditions, and is dependent rather on altered osmosis than on difference in oxygenation.
Small doses of the potassium salts (excepting the permanganate) cause a fall in the pulse-rate, but a rise in the arterial pressure, probably through the vaso-motor nerves; this effect is usually only temporary (Aubert, Dehn). Full doses lower both pulse-rate and blood-pressure. The lowered pressure may, or may not, be followed by a rise according to the dose employed. Parkes found a full dose of liquor potasso3 render the pulse small and slow, but a copious secretion of urine explained this effect. Under the nitrate the pulse-frequency came down in a few days from 76 to 61 (Rabuteau, p. 229), and the chlorate, according to Socquet, of Lyons, has a similar sedative action. Some observers report a quickened circulation, especially after venous injection of chlorate (Gubler); Jacobi speaks of this salt congesting the kidney (Medical Times, i., 187G), and Osborn of its congesting the brain (Lancet, ii., 1859); but such effects must be exceptional. The observations of Black (1839), and of Bouchar-dat (1814), and the experiments of Podocaepow (Virchow's Archiv, Bd. xxxiii., p. 505), of Guttman, Aubert, Dehn, and others agree in assigning to potash salts a distinctively depressing effect on the heart-action. Their injection in frogs quickly lessens the force of the blood-current, and finally arrests the heart in diastole: 10 gr. of chloride injected into the jugular vein of the smaller animals cause instant cardiac death, and since the heart-muscle in such cases is found insensitive to electricity (Traube), and since previous section of the vagi has no influence on the result, we conclude that the cardiac arrest is due to a direct paralysis of the muscular substance. This paralysis is commonly preceded by increased activity, but finally it becomes complete, so that the heart-muscle ceases to react to any ordinary stimulus. If, however, the potash chloride be introduced gradually into the system through the stomach, then cardiac contractility is not entirely destroyed by it.
The bitartrate of potash has some power of arresting hemorrhage, especially from the kidney (Ramskill and others, Ranking, i., 1867); it possibly lessens congestion by diuresis or purgation. Albuminuria has occurred under the influence of nitrate.