Therapeutics And Administration

1. As a counterirritant - ammonia liniment or ammonia water. As a blistering-agent to the gums - ammonia water.

2. As a rapid reflex circulatory and respiratory stimulant in fainting or feelings of faintness - ammonia gas inhaled from ammonia water or smelling salts; or the aromatic spirit of ammonia, taken by mouth. Smelling salts are mostly made of cakes of ammonium carbonate covered with an alcoholic solution of ammonia containing aromatic oils, such as the oil of lavender.

3. As an antacid carminative in digestive disturbances and headache, and as a morning "pick-me-up" after a debauch - the aromatic spirit.

4. As an expectorant to fluidify thick and tenacious mucus of the respiratory tract - the carbonate.

Contraindication

Urea retention, as in nephritis and uremia.

II. The Ammonium Compounds Which Are Not Dependent for Their Activity on Their Liberation of Nh3

1. Ammonium Chloride

The chloride or muriate of ammonia or sal ammoniac (Nh4c1) has a sharply salty taste, and is soluble in 2 parts of water and 50 of alcohol. Dose, 8 grains (0.5 gm.). The only official preparation is the troche (trochiscus ammonii chloridi), which contains 1 1/3 grains (0.09 gm.) of ammonium chloride with sugar, licorice, etc.

Pharmacologic Action

The chloride liberates ammonia very slowly indeed, and is neither antacid nor caustic.

Local Action

It has a marked salt action, i. e., in strong solution shrinks the tissues by abstracting water, and is irritant. In proper dilution it is only slightly irritant.

In the mouth it is irritant and astringent, causing shrinkage of the membranes; but in response to the irritation there is a prompt reflex flow of saliva, which serves as a diluent and moistens the mouth. In the stomach, it is also irritant unless well diluted.

Absorption

The chloride is rapidly absorbed from the stomach and is not converted to urea in the liver (Bainbridge). (The sulphate, in which the ammonium ion is combined with the non-penetrating sulphate ion, is not readily absorbed and is consequently laxative, but it is not employed in medicine.)

Its systemic action is essentially, if anything, to increase secretions, and it has the reputation of increasing and fluidifying the mucous secretions of nose, throat, and bronchi. Ammonia is not found in the expired air, but Coleman, 1916, finds the ammonia nitrogen of the sputum increased from 2 to 5 times after 5 grains (0.03 gm.) every two hours for twelve doses. He also states that the sputum tastes of ammonium chloride and is more fluid and looser. He suggests that in passing through the bronchial wall the salt increases the water of the secretion and so lessens the viscosity of the sputum. Henderson and Taylor believe any effect to be a reflex one, the result of a nauseant action. (See Expectorants.) By its action as a salt it may slightly increase, the other secretions, especially the saliva, the sweat, and the urine. It is not a circulatory stimulant, either reflex or direct.

Excretion

Traces have been found in several secretions, but almost all of it is excreted as ammonium chloride in the urine, the reaction of the urine and the amount of urea being practically unchanged. After 175 grains (5 gm.) of ammonium chloride, Wolf and Osterberg recovered 52.2 per cent. in the urine in two days. In bronchitis it appears in the sputum (Coleman). It has been calculated that the chloride ingested is broken up in the liver or in other parts of the body with the liberation of hydrochloric acid and the formation of urea, the Hc1 thus set free being immediately neutralized and changed back to ammonium chloride by Nh3 manufactured by the body cells; and that it is this freshly manufactured chloride that is excreted. This may be true, but in any case, as suggested by the work of Bainbridge on the lymph of the thoracic duct, what leaves the liver, is the chloride, and ammonia poisoning does not result.

Therapeutics

For acute pharyngitis the troches or tablets may be dissolved in the mouth - a favorite remedy of the laity. Thus employed, the chloride is stimulating and astringent, so that it causes a drawing up of the relaxed mucous membrane, with removal of its edematous state; it also promotes the flow of saliva, so may relieve congestion and dryness of the throat. In laryngitis or bronchitis the drug is occasionally inhaled as vapor, the vapor being formed by exposing thechloride to heat or by the admixture of ammonia and hydrochloric acid gases in a special apparatus. But its most frequent employment is in cough mixtures, to increase the flow of mucus in the dry stages of nasal, throat, and bronchial inflammations, i. e., when the congestion is great without mucous flow, or when the mucus is thick and tenacious.

2. Ammonium Acetate

The acetate, Nh4c2h3o2, is an unstable salt, and on this account is prepared in solution when required. There are two official preparations - the solution of ammonium acetate (liquor ammonii acetatis; spirit of mindererus), and the solution of iron and ammonium acetate (liquor ferri et ammonii acetatis; Basham's mixture), the dose of each of which is 2 drams (8 c.c.). The solution of ammonium acetate should be freshly prepared, and should contain Co2 gas. It is a palatable, slightly salty preparation, is quickly absorbed, and is changed to urea in the liver, the urea promoting the flow of urine. It may also have a tendency to increase the sweat. It is employed as a refreshing but weakly acting diaphoretic and diuretic in fevers, especially those of children. Bashaw's mixture is a palatable iron preparation. As it contains free acid, it should be administered well diluted and through a tube, to protect the teeth. It is employed in anemic conditions for its iron, and in functional albuminuria or chronic nephritis for both its iron and its ammonium acetate.

3. The other official salts of ammonium are the bromide, iodide, benzoate, salicylate, and valerate. In these the effect of the ammonium radicle is overshadowed by the relatively more potent acid radicle, so that these salts, except in large doses, have practically the action of the potassium and sodium salts of the same acids. They belong, pharmacologically, with the groups of bromides, iodides, salicylates, etc.