Source and Composition. The tuber of Aconitum Napellus, a perennial plant of the nat. ord. Ranunculaceae, (Monkshood), found in mountainous regions. Its active principle is the alkaloid Aconitine, which it contains in the proportion of .03 per cent., together with Aconitic Acid. Other varieties of Aconite are said to contain several other principles, concerning which the authorities are much divided, viz.—Napelline, Aconine, Pseudaconitine, Lyctonine, etc., but it is generally conceded that Aconitum ferox, from Nepaul, contains Pseudaconitine, which is much more active than Aconitine; —also that a Japanese variety contains an alkaloid which is more powerful than even Pseudaconitine.
- Extractum Aconiti, Extract of Aconite,—Dose, gr. ⅙-⅓.
- Extractum Aconiti Fluidum,—alcoholic. Dose, ♏¼-ij.
- Tinctura Aconiti, Tincture of Aconite, -strength 35 per cent. Being a preparation of the root, it is about 25 times more powerful than the former tincture of the leaves, which is still to be found in the shops. Fleming's Tincture has 79 per cent., the Br. 16, the French 20, the German 10; so that great care must be used not to mistake one for another. Dose, ♏ss-iij.
- *Aconitina, Aconitine,—Dose, gr. 1/200-1/50. Is difficult to obtain of constant strength, some samples being all but inert, others extremely active. The "Aconitine Cristalisée" of Duquesnel (a Nitrate of Aconitine, Squibb), is considered the most active of the samples in the market.
- *Oleatum Aconitinae, Oleate of Aconitine,—2 per cent., for external use.
- *St. Jacob's Oil,—is a weak Aconite Liniment which also contains Ether, Alcohol, Turpentine, red coloring matter, and Water (Squibb).
Physiological Action. The taste of Aconite is bitter, acrid, and pungent. Soon after the ingestion of even a small quantity, a sensation of numbness and a persistent tingling are felt in the tongue and lips. Full medicinal doses cause a sense of constriction in the fauces, irritation of the gastro-intestinal mucous membrane, with increased secretion; sometimes nausea and vomiting, and severe pains in the joints and muscles; always more or less salivation, diaphoresis and diuresis, reduced respiratory power, decreased cardiac rate and force, lowered arterial tension and. temperature. A Toxic Dose produces great muscular weakness, dimness of sight, dilated (sometimes contracted) pupils, shallow, irregular and labored respiration, a slow and weak pulse, coldness of the surface, clammy sweat, great anxiety, numbness and tingling in the extremities; lowering of the body temperature (20 to 30), abolishment of sensation, reflexes and motility; and finally death from paralysis of the heart and respiration, with or without convulsions, consciousness being preserved until near the end, when CO2 narcosis sets in.
Aconite is a powerful sensory, cardiac, respiratory, and spinal depressant, also diaphoretic, diuretic and antipyretic. It chiefly affects the peripheral ends of the sensory nerves, but paralyzes both motor and sensory nerves,—the sensory being affected first and from the periphery inwards, while the motor nerves are affected from the centres outwards. It relaxes the inhibitory apparatus of the heart, and paralyzes the cardiac muscle and its contained ganglia, the respiratory centres and the spinal cord in all its functions, (sensory, reflex and motor), but does not affect the brain. Aconite is rapidly diffused and slowly excreted; the effects of a full medicinal dose continuing for three or four hours. Applied externally it paralyzes the sensory nerves of the part, producing its characteristic numbness and tingling.
Toxicology. Caffeine, Atropine, Morphine, Ether, Ammonia and Amyl Nitrite antagonize its effects on the heart and respiration. Digitalis counteracts its heart action and the relaxation of cardiac inhibition. (See ante, page 106.) In aconite poisoning, the stomach should be evacuated, warmth applied to the extremities, stimulants administered, artificial respiration if necessary, and the recumbent posture strictly maintained.
Therapeutics. Aconite antagonizes the fever process, and rightly used is, therefore, one of the most valuable drugs we possess. It has been called the "therapeutic lancet," and certainly is responsible to a great extent for the disuse into which venesection has fallen. Its power over the circulation, respiration and transpiration renders it of the greatest value in all affections characterized by high resisting pulse, dry, hot skin, and elevated body-temperature. It is especially useful in—
- Acute Throat Affections, as tonsillitis, pharyngitis, etc.,—drop-doses of the tincture every hour are remarkably efficient in these conditions.
- Acute Inflammations of the Respiratory Organs, as bronchitis, coryza, pneumonia etc.,—Aconite is efficient in the early stage, when there is present a sthenic febrile action, with high temperature.
- Acute Pleuritis and Peritonitis, previous to the stage of effusion,—Aconite combined with Opium is considered to be the best treatment.
- Simple and Eruptive Fevers, particularly scarlet fever and measles,—are best treated by small repeated doses of Aconite, which in measles is particularly efficient from its power to arrest the catarrhal pneumonia.
- Puerperal Fever,—Aconite steadily used, with an occasional dose of Castor Oil, is one of the best agents in the metritis form of this disease.
- Surgical Fever is promptly met by Aconite, which is especially useful in preventing chill after the passage of the urethral sound or catheter.
- Erysipelas Faciei,—Aconite is highly serviceable, and usually curative.
- Acute Rheumatism,—has been extensively treated with Aconite, and always with the best results. It lessens the duration of the fever, mitigates the pain and swelling of the joints, and prevents the occurrence of organic heart disease, if used from the commencement (Phillips).
- Cardiac Affections characterized by over-action or hypertrophy, without valvular lesions,—are benefited by Aconite in small doses repeated.
- Diarrhoea and Dysentery, from cold or exposure,—Aconite is unquestionably beneficial. It also relieves Constipation in patients of plethoric habit, with dry, hot skin, and a feverish tendency.
- Menstrual Suppression from chill,—Aconite often relieves promptly.
- Neuralgia, especially of the face or brow,—Aconite is very efficient, having a selective influence on the 5th nerve. It may be used internally and also applied locally over the seat of pain; for the latter purpose a reliable Aconitine should be used, mixed with Chloroform and Oleic Acid, the Chloroform aiding the inward osmosis of the drug.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.