Anti-Emetics Acting On The Stomach

These are all those substances which have been already enumerated as having a sedative influence on the gastric nerves, viz.:

(1) Ice.

(2) Bismuth subcarbonate.

(3) Bismuth subnitrate.

(4) Opium.

(5) Hydrocyanic acid.

(6) Carbon dioxide.

Also some drugs which occasionally appear to have a specific local action in arresting vomiting; such are:

(1) Cocaine.

(2) Cerium oxalate.

(3) Menthol.

(4) Wine of ipecac.

(5) Tincture of iodine.

(6) Arsenous acid.

In minute doses.

(7) Alcohol.

(8) Carbolic acid.

(9) Chloroform.

(10) Creosote.

(11) Ether.

(12) Silver nitrate.

(13) The sulphocarbolates.

In small doses.

Anti-emetics acting centrally -

(1) Opium.

(2) Ammonium,

(3) Potassium, and

(4) Sodium bromides.

(5) Chloral hydrate.

(6) Amyl nitrite.

(7) Nitroglycerin.

(8) Diluted hydrocyanic acid.

(9) Alcohol.

It will be noticed that some drugs fall under both headings.

Therapeutics

The very name of these drugs indicates their therapeutical application. At the best they are only palliative; the right way to treat vomiting is, if possible, to remove the cause. Of anti-emetics, ice, diluted hydrocyanic acid, carbon dioxide, bismuth salts, morphine, menthol and iodine are perhaps the most reliable, but all are very uncertain.

D. Drugs acting on the intestines. - Many secretions are poured into the intestine, the food is much altered by the time it arrives there, and it is changed in its course down the intestine; the physiology of intestinal digestion, of the movements and the nervous mechanism of the intestine are imperfectly known; drugs may be considerably altered by the time they come to this part of the alimentary canal, and its diseases are little understood; consequently we cannot arrange the action of drugs in a physiological classification. We know, in fact, of only three important divisions: purgatives, antiseptics and astringents.

The methods of experiments which have been used to determine the mode of action of purgatives are chiefly those of Thiry and Moreau. The first-named observer cut the intestine across in two places a short distance apart; the isolated part which was still attached to the mesentery was sewn up at one end; the other, the open end, was attached to the abdominal wall, and thus there was a test-tube-like piece of intestine into which drugs could be placed. The parts of intestine, on either side of the excised piece, were sewn together, so that the whole intestine was the same as before, but a little shorter. This method did not give very satisfactory results, and consequently Moreau devised his experiments, which seem more trustworthy. He put four ligatures around the intestine at equal distances apart, so that he shut off from the rest of the intestine and from each other three pieces of intestine, each of the same length. With a fine syringe he injected into the middle piece the drug to be experimented upon, and returned the whole into the abdominal cavity. In a few hours the animal was-killed, and the state of the interior of the middle piece was contrasted with that of the pieces either side of it. Before Moreau's experiments there had been much discussion as to whether some purgatives did not act only by increasing the action of the muscular coat, and others only by stimulating the secretions, but from these experiments it appears that probably the majority act in both ways, some very slightly on the secretion and powerfully on the muscle, and others slightly on the muscle and powerfully on the secretion. We will first consider intestinal purgatives, then intestinal antiseptics and finally intestinal astringents.

Purgatives are divided into the following classes.