This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Colorless or slightly opaque rhombic crystals; or a fine, white, somewhat gritty powder, odorless, and having a pleasant, acidulous taste. Solubility. - In 201 parts of water; very sparingly soluble in Alcohol.
Calcium tartrate, copper, lead, and iron. Potassium Bitartrate is contained in Pulvis Jalapae Compositus. Dose, 20 to 60 gr.; 1.20 to 4.00 gm. (diuretic and refrigerant); 1/2 to 4 dr.; 2. to 15. gm.; (purgative).
One of these being only slightly acid and the other neutral, they have none of the external caustic or antacid properties of other potassium salts.
Intestines. - Both salts are typical hydragogue saline purges, producing easy, soft, watery motions without griping. They abstract fluid from the blood, and cause it to be poured into the intestine. Their mode of action has already been fully described (see p. 93).
Potassium sulphate is a moderate cholagogue, slightly increasing the biliary flow.
The bitartrate is diuretic, because a small amount of it is, in the intestine, converted into a carbonate and absorbed, and this acts directly on the renal cells. Hence it renders the urine alkaline. But all the sulphate and most of the bitartrate is excreted with the faeces, and if, as seems probable, some is absorbed by the small intestine in the form in which it is taken, it is excreted again into the colon.
These excellent purgatives are frequently used, especially for habitual sluggishness of the bowels. A dose should be dissolved in a tumbler of hot water, and sipped during dressing. They may be employed to open the bowels in cases, such as dropsy or uraemia, in which we wish to eliminate as much fluid as possible. They should for this purpose be given in a concentrated form, for then a large amount of fluid will be secreted from the intestine to bring the solution of the salt to that degree of dilution at which it will act. Compound jalap powder which contains potassium bitartrate is also much used for this class of cases. The sulphate having some cholagogue action, is to be preferred when it is believed that the liver is at fault.
These salts are often given to those who suffer from gall-stones, although no potassium salts have any power to dissolve gall-stones, but the sulphate does good as a cholagogue.
The bitartrate is sometimes used as a diuretic in the same class of cases as the acetate and citrate. A very pleasant drink for feverish patients is Imperial drink. It contains potassium bitartrate, 60 gr. 4.00 gm.; saccharin, 1 gr. .06 gm.; oil of lemon, 3
20 c.c.; to a pint 500. c.c. of boiling water.