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..
These may be described under the following heads:
(1) Lead salts.
(2) Dilute solutions of silver salts.
Astringents coagulating albuminous fluids and thus constricting the vessels: -
(1) Tannic acid, and all substances containing it, as -
(6) Catechu, and
(7) Eucalyptus gum.
(8) Lead salts.
(9) Silver salts.
(10) Zinc salts.
(11) Bismuth salts.
(12) Copper salts, and especially
(13) Ferric salts.
Astringents diminishing the amount of intestinal fluid secreted:
(3) Lead salts.
(4) Calcium salts.
The precise action of these is obscure, but it is probable that they operate in the way indicated.
Astringents diminishing the contractions of the muscular coat of the intestines:
(5) Lead salts.
(7) Bismuth salts.
The first proceeding in every case of diarrhoea is to remove its cause; if this can be done, it will probably subside. Often the cause is some irritating, indigestible food, and then it is advisable to give a mild purge, as castor oil, rhubarb, etc., to get rid of it. The majority of cases of ordinary diarrhoea are probably due to some slight enteritis, and then any one of the astringents that have been named will be valuable, for it is desirable to constrict the dilated vessels, and to diminish the secretion and the movements. Intestinal astringents are, therefore, often combined, and, when the diarrhoea is at all serious, opium is of great service. If there is a persistent cause, as tuberculous ulceration, the hope of doing good is slight. But the treatment by drugs is only a small part of the battle; if the diarrhoea is severe, absolute rest is necessary, food must be very simple and given in small quantities at a time, not much fluid should be drunk, and the patient must be kept warm.
E. Drugs acting on the Liver. - The liver has several distinct functions, viz.: (a) to secrete bile; (b) to form and store up glycogen; (c) to form urea; (d) to excrete substances absorbed from the intestine; and (e) to destroy poisonous substances absorbed from the intestine.
1. Drugs influencing the secretion of bile. - It does not follow because more bile appears in the faeces that more is secreted, for it may be that the gall-bladder and ducts have been thoroughly emptied, or that the bile which has been poured into the duodenum has been swept along quickly before reabsorption, which is ordinarily brisk, has had time to take place. Drugs which increase the amount of bile actually secreted are called direct cholagogues, or hepatic stimulants; but this is a bad name, as the liver has so many distinct -functions: those which simply lead to a larger amount of bile being found in the faeces without any extra secretion are called indirect cholagogues.