This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Aconitum (U. S. P.). Aconitum Napellus is official in twelve pharmacopeias in the form of the root, and the leaves in the French, Mexican, and Spanish standards.
Aconitum Fischeri, known as Japanese and Chinese aconite, an exceedingly toxic species, grows abundantly in the Western States of America. It may, in time, become an important source of supply in the United States.
Aconite, cevadilla, and staves-acre are pharmacologically similar, but are not similar therapeutically, an instance - one of many - showing that pharmacology may not dominate therapeutics any more than the science of optics may dominate art. Yet the pharmacology of aconite is important.
Locally aconite produces numbness, abolishes thermal sensation, diminishes tactile sensation; on mucous membranes there is a paralyzant action and local anesthesia.
Aconite is rapidly absorbed when swallowed, there being a feeling of burning and nausea, and vomiting and abdominal pain when sufficient dosage is absorbed. The temperature falls; there are weak cardiac contractions, and death follows from respiratory failure, with dyspnea and asphyxia and paralysis of the respiratory center. Atropine may retard the fatal result.
In small doses the rate and contractile force of the heart is diminished, especially in conditions of pyrexia. In larger doses the cardiac muscle is directly poisoned and blood-pressure falls.
The brain is little affected and the motor centers remain active; however, the medullary centers are affected, with a fall in temperature.
Sweating is induced, not by direct action, but indirectly, probably by peripheral sensory irritation.
Aconite causes a depression of the central heat-regulating mechanism; and in pyrexia repeated small doses will do this.
Oxidation processes are diminished during administration. Excretion is chiefly in the urine, being found within four hours after administration.
These are the actions upon man; there are other minor actions noted on the lower animals, and the pharmacology of the isolated alkaloid presents points of variation from the above.
It has been asserted that aconite is a stimulant to the sympathetic nervous system. I can find no sustained evidence in support of this contention. There are many statements made regarding the actions of drugs upon the sympathetic nervous system which are based upon predilection, not on evidence. Aconite does not, as has been claimed, "increase the power of the heart to move the blood," not even in small doses.
Externally aconite diminishes pain due to peripheral irritation, as in peripheral neuralgia, liniments of aconite, belladonna, and chloroform having a wide range of usefulness.
In full medicinal doses (tr. 5 to 10 minims; fl. 1/2 to 1 minim) aconite is highly useful in a considerable range of cases characterized by high blood pressure with a strong, rapid heart, particularly sthenic fevers in the robust. In these cases it promptly slows the heart and causes a fall in arterial tension, as well as reduces fever. But fever alone is not an indication for aconite; it has no place in continued fevers, or where arterial tension is low, regardless of pulse rate, or when the heart is feeble. Aconite is a remedy for the first stages of disease, the first twenty-four to forty-eight hours.
In moderate medicinal doses (tr. 3 to 5 minims; fl. 1/4 minim) aconite is a most useful remedy in a wide range of inflammatory conditions. In these doses the action is limited to slowing the heart, slightly reducing blood pressure, and abating fever. Acute tonsillitis, laryngitis, and catarrhal involvements in adults, suppression of the menses, the early stages of sthenic pneumonia, bronchitis, gonorrhea (of course only to relieve symptoms), peritonitis, acute pleurisy, and as an adjuvant in the treatment of acute rheumatic fever, are leading indications. Here I wish to quote a most sensible expression from "The Pharmacopeia and the Physician" (1910), which said:
"Since the antipyretic benzene derivatives have come into general use the employment of aconite in fever has correspondingly declined, but we have seen that the synthetic antipyretics are far from being the harmless substances that some of the manufacturers would have us believe, and aconite deserves to be used more frequently in suitable cases of fever."
Small doses (tr. 1 to 2 drops; fl. 1-10 to 1-5 drop, frequently repeated) of aconite are most useful in "colds," the exanthems, many of the diseases of infancy, and inflammatory diseases generally. Even smaller doses are used by Homeopathic physicians in all cases of fevers with suppressed secretions, chilliness upon slight exposure, and a pulse that is quick and sharp, as well as in "restlessness" and other minor disturbances caused by deranged circulation. Aconite cooperates well with many other drugs, as, for instance, with Dover's powder in the early stages of a "cold" and with the expectorants.
Aconitine (U. S. P.) is used in doses of 1-640 to 1-400 grain well diluted or in granules, and for external use in ointments up to 2%. There are a number of forms of this alkaloid, the so-called "mild" in amorphous form, the crystalline alkaloid, etc. There is no real occasion for using this expensive and frightfully toxic alkaloid externally, and, I believe, very little for its internal use. I have used the minimum-dose granules in many cases of sthenic character; but such reliable standardized tinctures are now made that I have wholly abandoned the use of the alkaloid.