Mode of Operating

The local irritant properties of lobelia, as of digitalis and tobacco, may give rise occasionally to a sympathetic excitement of the circulation; but the direct effects of the medicine, after absorption, are undoubtedly, I think, sedative. From the experiments upon animals above mentioned, and from the intense nausea produced by the medicine, it might be inferred that its influence is prominently directed to the nervous centres which govern the functions of the respiratory organs and the stomach; and that the heart is secondarily involved; but more numerous and diversified observations are necessary to justify a positive conclusion upon these points. That the medicine is absorbed has not been absolutely proved, but may be fairly deduced from the strong analogy between its action and that of tobacco; and from the fact that, when injected into the rectum, it produces the same nausea, vomiting, profuse perspiration, and general relaxation as when taken by the stomach.

Therapeutic Application

Lobelia was used as a remedy by the aborigines, and was long empirically employed before it was adopted by the regular profession. it was first brought into general notice by the Rev. Dr. M. Cutler, of Massachusetts. in a communication published in Thatcher's Dispensatory, he speaks of its extraordinary efficacy in the relief of spasmodic asthma in his own case, in which he was induced to employ it by the representations of Dr. Drury, of Marblehead, in September, 1809. (Barton's Veg. Mat. Med. of U.S., i. 191.) Since that time it has been much employed in the same and other spasmodic affections, though the use of it has been greatly abridged by the unfavourable results of its abuse, and the unfounded fears originating in this cause. When properly employed, lobelia is probably as safe as any other medicine acting powerfully on the nervous system; certainly quite as safe as tobacco, which it resembles in its effects, though considerably weaker.

It is chiefly with a view to the relaxation of spasm, that lobelia has been used as a sedative. Almost all writers unite in bearing testimony to its occasional extraordinary efficacy in the paroxysm of spasmodic asthma. it is, on the whole, the most efficacious remedy that I have myself employed in that affection. Given in the dose of half a fluid-ounce of the tincture, it generally produces nausea and vomiting, and not unfrequently affords prompt relief. I prefer, however, administering it in the smaller doses of one or two fluidrachms, repeated every half hour, hour, or two hours, until it excites nausea, and maintaining a moderate amount of this condition until the spasmodic symptoms are relieved. Should catarrhal inflammation, as not unfrequently happens, accompany the spasmodic attack, it may be proper to precede its use by bleeding, and to employ the powder preferably to the tincture, in consequence of the alcohol contained in the latter. Like all other remedies, however, it sometimes fails in asthma; though I do not think I have ever used it without benefit.

Even in the dyspnoea connected with chronic organic disease of the lungs and heart, especially when it occurs paroxysmally, the remedy may be employed with advantage.

i have been in the habit of using it in bronchial inflammation, after due depletion, whenever I have had reason to think that it was in any degree complicated with spasm of the bronchial tubes. it operates here not only as a nervous sedative, but also as an expectorant. it should, however, be associated with other expectorants, as tartar emetic, ipecacuanha, or squill.

In pertussis it has been recommended by the late Drs. W. P. C. Barton and Eberle, who employed it in several cases with unequivocal advantage. Dr. Eberle gave from fifteen to twenty drops of the tincture, with ten or twelve drops of syrup of squill, every two or three hours, to a child between one and two years old. He also found it, in combination with extract of belladonna, very efficacious in mitigating the disease. (Treat. on Mat. Med. and Thérap., 4th ed., i. 88.) it has also been recommended in croup; and, in the catarrhal variety of that affection, without false membrane, it will often prove very serviceable by relaxing the spasm. But it is probably in no degree superior to tartar emetic, and from the uncertainty of its dose, and the danger of its abuse, is not advisable in that affection, unless as an adjuvant of other measures, when simple emesis has failed to produce relief. I have in this way used it with apparent advantage. To the pseudomembranous variety it is inapplicable.

In strangulated hernia, it was employed with success by Dr. Eberle; half a pint of a strong decoction of the fresh herb having been given by enema, followed soon afterwards by half the quantity. Distressing nausea came on, with profuse perspiration, and universal relaxation, in which condition the hernia was reduced without difficulty. (Barton's Veg. Mat. Med., ut supra, p. 198.)

Lobelia is stated also to have proved useful in delivery, by relaxing rigidity of the os uteri, being given in small doses so repeated as to occasion slight nausea. (Am. Journ. of Med. Sci.,xvii. 248) it is a favourite remedy with the practitioners calling themselves eclectics, who use it in most spasmodic diseases, besides those already mentioned, as in epilepsy, chorea, hysteria, tetanus, cramps, and convulsions. They also employ it externally as an anodyne in sprains, bruises, rheumatic and neuralgic pains, spasms, etc. in most of these complaints, it may no doubt be used with occasional benefit. A case of recovery from traumatic tetanus is recorded by Dr. J. McF. Gaston, of Columbia, S. C, in which lobelia was the chief agent employed. (Charleston Med. Journ and Rev , xi. 56.) it is contraindicated by irritation or inflammation of the stomach and bowels.

Administration

The dose of the powder, as an emetic, is from ten to thirty grains; as a nervous sedative and nauseant simply, five grains, repeated every hour or two, the quantity being increased or diminished according to the effect produced, and the medicine suspended if vomiting or prostration ensue.

A Vinegar of Lobelia (Acetum LobeliaE, U. S.) is directed in our Pharmacopoeia, being prepared in the proportion of four troyounces of the powdered leaves to two pints of diluted acetic acid. it is a good preparation, having the special recommendation that the acetic acid protects the alkaloid of the leaves from decomposition. The dose is from thirty minims to a fluidrachm, which, in cases of spasmodic asthma, may be increased during the paroxysm to one or two fluidrachms, repeated every two or three hours till relief is obtained. For an emetic effect the dose would be half a fluidounce.

The Tincture (Tinctura Lobeliae, U.S., Br.) is made, according to the U. S. Pharmacopoeia, in the proportion of four ounces to two pints of diluted alcohol. Consequently, supposing the herb to be exhausted, a fluidounce would be equivalent to a drachm of the powder. The emetic dose of the tincture is about half a fluidounce; the nauseating and sedative dose, a fluidrachm. it is recommended as an excellent local remedy in erysipelas, and in the poisonous effects of Rhus Toxicodendron, by Dr. M. Livezey, of Lumberville, Pa , who applies it by means of linen cloths saturated with it, and frequently renewed. (Bost. Med. and Surg. Journ., lv. 262.)

An Ethereal Tincture (Tinctura Lobeliae AEtherea, Br.) is directed in the British Pharmacopoeia; being prepared with spirit of ether, instead of diluted alcohol. it is probably in no respect preferable to the simple tincture; while the ether renders it unnecessarily, and sometimes injuriously stimulating. Should lobelia and ether be simultaneously indicated, it would be better to use the simple tincture with Hoffmann's anodyne. The dose is the same as of the preceding preparation.