(Unofficial.) This is an ammoniacal substance, having a strong, fishy odor. It is isomeric with propylamine, which is also an ammonia. As the propylamine of commerce is a mixture of various substances, and is of uncertain composition, trimethylamine only should be used (Spencer). The dose of trimethylamine is four to eight minims. Its disagreeable taste may be disguised somewhat by peppermint-water.

Properties

Trimethylamine is a colorless liquid, having the composition C3H9N. It dissolves freely in ether, alcohol, and water, has a strong alkaline reaction, and is inflammable.

Chloride of Trimethylamine is a stable salt which crystallizes in long needles; it is very deliquescent, and its solution when concentrated has a caustic action on the skin and mucous membrane. It is free from odor, except when heated or mixed with an alkali, when the fishy smell is evolved. The taste of a solution of this salt is alkaline, but not disagreeable (Dujardin-Beaumetz). Dose, grs. ij to grs. v every three hours.

Antagonists and Incompatibles

Chemically trimethylamine is incompatible with the mineral acids, the salts of the metals, the alkalies (chlorides), and vegetable infusions. It should always be prescribed alone, in solution in some aromatic water. Therapeutically, it is antagonized by the stimulants, opium, belladonna, digitalis, etc.

Synergists

All agents depressing the vascular system and the temperature are synergistic.

Physiological Actions

Applied to the skin, mucous membrane, or areolar tissue, trimethylamine produces decided caustic effects, comparable to those which result from the action of ammonia. It excites gastric pain when taken into the stomach in considerable doses, and will, doubtless, cause a high degree of inflammation if incautiously administered. The most characteristic effects are the lowering of the action of the heart, the depression of the temperature, and the diminution in the amount of urea excreted. In the physiological state Dujardin-Beaumetz found, in some experiments on himself, that the chloride of trimethylamine lessened the temperature and the pulse, but these results were much more decided when it was administered in cases of acute rheumatism. The influence which this agent has on the excretion of urea is still more remarkable. The observations of Dujardin-Beaumetz show that a gradual but considerable decline in the excretion of urea is a constant result of its administration. On the other hand, Spencer says that the excretion of urea is sometimes increased, and, in one case in which the urinary discharge was carefully studied, the urine was almost trebled, and the urea more than doubled by the use of this remedy. If the diminution of the amount of urea were a constant result, as claimed by Dujardin-Beaumetz, the influence which trimethylamine has on the body temperature might be due to an interference with the combustion process. But the facts do not as yet justify the construction of a theory as to its mode of action.

Therapy

Thus far almost the only application made of trimethylamine is in the treatment of acute rheumatism and gout. In some cases it appears to produce almost complete relief after the administration of a few doses, but generally a longer time is required (Awenarius, Dujardin-Beaumetz, Spencer, Leo). It moderates, at once, the fever and the joint-pain, and very decidedly shortens the duration of the disease. It is said to diminish the tendency to cardiac complication.

This agent, having so decided an influence on the pulse, temperature, and excretion of urea, will in the future doubtless be applied to the treatment of other maladies.

Authorities referred to:

Buchheim, Dr. Erwin. Ueber das Trimethylamin. Schmidt's Jahrbücher, vol. lxxxiii, p. 13.

Dujardin-Beaumetz, Dr. Du Chlorhydrate de Triméthylamine dans le Traitement du Rhumatisme Articulaire Aigu. Bulletin Général de Thérapeutique, vol. lxxxiv, pp. 337, 395.

Leo, Dr. Berliner klinische Wochenschrift, 1875.

Petit, M. A. Sur la Triméthylamine. Bulletin Général de Thérapeutique, vol. lxxxiv, p. 313, et seq,

Spencer, Dr. W. H. On the Employment of Trimethylamine in Rheumatism and Gout. The Practitioner, February and March, 1875.