Therapeutic Application

From the ascertained physiological properties of Calabar bean, it may be inferred to be therapeutically applicable to a considerable number of diseases. in the first place, in consequence of its sedative influence on the spinal marrow, and the actions of the heart, it would appear to be indicated in conditions of disease essentially dependent on irritation of these structures. in tetanus, the poisonous effects of strychnia, and all other spasmodic or neuralgic affections having it has been tried in a few instances in tetanus, to which it would seem to be peculiarly applicable; but hitherto with only negative results. At least, the best that has been claimed for it is that it affords relief in that disease. in one case, which finally terminated favourably under the use of morphia, the extract was given on one day in a quantity equivalent to 32 grains of the kernel, and on the following day, equivalent to 56 grains, with no satisfactory result, and was then abandoned. (Lancet, March, 1864, p. 349.)

* The following is the experience of Dr. J. S. Wells in reference to this effect of Calabar bean. The inside of the lid was touched with one-tenth of a minim of a solution of the extract. in 5 minutes there was a slight feeling referrible to the ciliary region. in 10 minutes, besides this sensation, there was a sharp pain in the same region; reading was painful, and the letters appeared confused. This was owing to disturbance of the accommodation. in 15 minutes the focus of vision was at 6| inches, instead of 15 inches, at which it stood before the experiment. in 20 minutes the pupil became rather suddenly contracted to the size of a large pin's head. in 25 minutes it was extremely small. At the end of 18 hours, the eyes were restored to their normal power of accommodation; but the pupil still remained contracted. (Braithwaite's Abst., No. 48, p. 146.) their origin in irritation or active congestion of the spinal centres, even in cases of incomplete paralysis dependent on the same cause, as evinced by tingling, numbness, formication, etc., while yet the condition within the cord is that of excitement, the indications for this remedy are very decided, if the views of its physiological action presented in this article are correct. The same may be said of palpitation and neuralgic disorder of the heart, and all other affections dependent essentially upon original cardiac irritation. in cases of excessive heart action caused by various morbid affections elsewhere, as in fevers and acute inflammations, our remedies must be addressed to the proper seat of the disease, and little can be expected from this remedy, or any other which depends for its usefulness simply upon its sedative influence on that organ. in tho second place, the peculiar influence of Calabar bean on the pupil, and on the ciliary muscle regulating the power of accommodation of the eye, would suggest its usefulness in morbid dilatation of the pupil originating in local causes; in cases of morbid far-sightedness; and whenever vision is disturbed from a defect of accommodation, arising from debility or local palsy of the ciliary muscle. Thus far, I have been treating of the rational therapeutics of Calabar bean; that is, of those applications of it which the judgment would suggest from a knowledge of its effects on the system in health. The time since the first discovery of its peculiar powers has been too short, and the supply of the medicine too limited to admit of an extensive trial of its practical virtues; so that it yet remains in a considerable degree undetermined how far its therapeutic usefulness may correspond with our impressions in relation to its peculiar powers.

To the same effect is the account which has been given of its efficiency in poisoning from strychnia. Both substances have been given, at the same time, in poisonous doses to the inferior animals, with no other result than some modification of their effects respectively. Death was not prevented.* More favourable reports have been made of the antidotal power

* Different results, however, were obtained by Dr. J. de Mello. Of a tincture of the bean, of which 15 drops injected into the jugular vein of a rabbit caused paralysis and death, he introduced 12 drops with 10 of the tincture of strychnia into the stomach of an animal, without observable effect from either. in the subcutaneous of the bean in belladonna poisoning. in a case of poisoning by atropia, which occurred at the hospital at Prague, Dr. Kleinwachter gave 10 drops of a solution of the extract of Calabar bean containing 6 grains in a drachm of glycerin, with the effect of violent vomiting in about a quarter of an hour, and subsequent entire relief of the symptoms. (B. and F. Medico-chir. Rev., Jan. 1865, p. 237.) Dr. Harley, of London, has used the medicine successfully in chorea. To a girl of 11 years, he gave one grain of the powdered bean gradually increased to three, three times a day, and afterwards increased the dose to four and a half, and ultimately to six grains; but the last-mentioned dose was given only once daily. The only inconveniences were occasional colics, and two or three vomitings. At first the pupil was contracted, and the pulse was accelerated to 144 and 160 in the minute; but these effects soon disappeared. {Ann. de Thérap., 1866, p. 51.) Other diseases in which the medicine is said to have been used beneficially are epilepsy, delirium tremens, acute rheumatism, and acute bronchitis; but neither in these nor in any other disease, should it be given when the pulse is feeble, and the system debilitated.

The bean has probably been used more in reference to its effect on the eye than for its systemic influence. For this purpose it is generally employed locally, as its operation in this way is more certain than when it is internally taken. in cases of dilated pupil, purposely produced for surgical purposes, it sometimes happens that the dilatation continues inconveniently long after the occasion for it is passed. Here the Calabar bean may be employed very effectively. The same condition resulting from weakness or paralysis of the circular fibres of the iris, or irritation of the straight ones, whether as an idiopathic affection, or as an attendant on other diseases, which is much more common, may occasionally be treated advantageously in the same way. impaired vision sometimes arises from a disordered condition, paralysis for example, of the ciliary muscle, following rheumatism, diphtheria, or other febrile affection, whereby the power of accommodation is lost. in such cases, Calabar bean has been found to restore normal vision, probably by stimulating the muscle referred to. it is useful also in cases of temporary presbyopia by diminishing the focal distance of the eye. Other applications of the remedy to affections of the eye have been suggested by ophthalmologists; but as yet, I believe, rather on theoretical grounds, than as the result of experience. Dr. Nunneley, however, has found it useful in preventing prolapsus of the iris, in wounds of the cornea and the margin of the sclerotica. {Lancet, July 18, 1863, p. 65.) tissue of a rabbit 5 drops of the tincture of the bean produced no observable effect; 8 drops caused paralysis of the hinder limbs, and from 15 to 20 drops caused death. [Journ. de Pharm. et de Chim., Juillet, 1866, p. 55.)

Administration

The kernel of the bean has sometimes been administered in the form of powder; the dose for an adult being from three to nine grains. A better form for exhibition is that of the alcoholic extract, of which, according to Dr. Edwards, of Liverpool, 5 or 6 per cent. is obtained from the kernel, when exhausted by three times its weight of rectified spirit. The dose of such an extract would of course be from 1/6 to 1/2 of a grain. But a still more convenient form is the tincture, which may be prepared by percolation from an ounce of the kernel and two ounces of alcohol, or enough to yield two fluidounces of tincture. The dose is from five to fifteen minims; five minims being equivalent to three grains of the kernel. (B. and F. Medico-chir. Rev., April, 1865, p. 536.) The smaller doses above mentioned will generally have effect in reducing the circulation; but they must usually be considerably increased before a decided impression can be obtained. (Dr. T. R. Fraser, Ed. Med. Journ., March, 1863, p. 824.)

For application to the eye, the minutest quantity of the extract mixed with water or glycerin will answer the purpose. Dr. Edwards states that, of a mixture of 5 grains of the extract with one fluidrachm of water, a single minim applied to the eye produces contraction lasting five days. (B. and F. Medico-chir. Rev., ut supra.) Much less than this will generally answer. All that is necessary is to moisten the point of a hair-pencil with the mixture and apply it to the inside of the lower lid. The same effect is obtained by placing on the inside of the lower lid a little piece of paper, about one-eighth of an inch square, previously moistened with the tincture and then dried. The contraction will take place in 20 minutes, and will continue a considerable time. A large piece of paper may be prepared at once; and cut when dry into pieces of the size mentioned. The extract may also be used for local application, dissolved in pure glycerin, in the proportion of from two to five grains to one hundred.