Expectorants are remedies which facilitate the expulsion of mucus from the respiratory organs. They do this largely by increasing the fluidity or the rate of the secretion. Most of them act reflexly from an irritant (nauseant) action in the stomach. Henderson and Taylor (1910) believed this to be the case with ammonium compounds, antimony, ipecac, and senega. Coleman holds that ammonium chloride fluidifies by increasing the water in the bronchi, which it carries out as the medium of its own excretion (see Ammonium Chloride). We have considered the ammonium salts, iodide, antimony, and pilocarpine. Others in common use are: Ipecac, 1 grain (0.06 gm.); senega, 15 grains (1 gm.), and aspidosperma (quebracho), 30 grains (2 gm.). Quebracho and its alkaloids, quebrachine and aspidospermine, have a peripheral action of the nicotine-curare type, and stimulate the respiratory center, hence have been employed in emphysema and asthma. In a test-tube the alkalies liquefy mucus, but when given by mouth probably have no effect in the bronchi.

Certain bronchial antiseptics have been mentioned under Antiseptics. Whether or not they act as true expectorants is a question; and whether they are eliminated in the bronchial mucus in sufficient quantity to stimulate the mucous membrane or to act as antiseptics has not been proved. They are: Certain volatile oil drugs, as oil of turpentine, terebene, pine needle oil, tar, creosote, camphor, cubebs, and garlic, dose, 5 minims (0.3 c.c.) or 5 grains (0.3 gm.); also terpin hydrate, dose, 5 grains (0.3 gm.), benzoic acid, benzoin, balsam of Tolu, and balsam of Peru. The syrup of tar, syrupus picis liquidae, has a dose of 1 dram (4 c.c.).

In some cases bronchial activity is promoted by the tonic action of such a drug as strychnine.

Favorite expectorant mixtures are:

1. The compound licorice mixture, brown mixture (not Brown's Mixture), which contains extract of licorice and spirit of nitrous ether, each 3 parts, paregoric 12 parts, and antimony and potassium tartrate 0.024 part in 100, with syrup, acacia, and water. Dose, 1 dram (4 c.c.). It is not a very effective expectorant.

2. The compound syrup of squill (Coxe's hive syrup), which contains 8 parts each of the fluidextracts of squill and senega, and 0.2 part of tartar emetic per 100. Dose, 1/2 dram (2 c.c.) every two or three hours.

3. Mistura pectoralis, N. F. (Stokes' mixture), containing ammonium carbonate, 8 grains (0.5 gm.), the fluidextracts of senega and squill, each, 15 minims (1 c.c.), paregoric, 75 minims (5 c.c.) in each ounce (30 c.c.), with syrup of Tolu. Dose, 1 dram (4 c.c.) every two or three hours.

Therapeutics

To promote the flow of mucus and lessen congestion in the respiratory tract, particularly in the dry stages of bronchial, nasal, or laryngeal inflammation.