This section is from the book "A Treatise On Therapeutics, And Pharmacology Or Materia Medica Vol2", by George B. Wood. Also available from Amazon: Part 1 and Part 2.
This is the product of different species of Artemisia, growing in Asia and the North of Africa. There are at least two varieties, corresponding with the commercial sources from which they are derived; one called Aleppo, Levant, or Alexandria wormseed,' brought from the eastern parts of the Mediterranean, and the other, Barbary wormseed, from the African coast. it is a mistake to call the product seeds. It consists of the unexpanded flowers, with the peduncles attached or separate, and minute leaves or fragments of leaves. A whitish down covering the Barbary wormseed distinguishes it from the Levant, which has a greenish colour. Both have an aromatic odour, and a bitter, disagreeable taste.
Active Principle. Santonin. Though Santonica contains a volatile oil, it is supposed that its anthelmintic virtues depend upon a peculiar principle called santonin. This is crystallizable, colourless, inodorous, and at first, on account of its insolubility, almost tasteless; but after a time it produces a slightly acrid impression, and its alcoholic solution is bitter. it is nearly insoluble in water, but is dissolved by ether and alcohol. it is fusible at a moderate heat, and assumes a crystalline appearance on cooling. At a higher heat it rises in white irritating vapours, which condense unchanged. it is, therefore, volatilizable. Mere contact with the air produces no change in it; but it becomes yellow when exposed to the direct light of the sun. Though neuter to test-paper, it seems to possess acid properties, as it unites with the alkalies to form neutral salts. it consists of carbon, hydrogen, and oxygen; its formula being C30H18O6. The British Pharmacopoeia recognizes it under the name of Santoninum, and gives a process for its preparation. This will be found in the 12th edition of the U. S. Dispensatory (p. 1329).
The general effects of santonica are probably those of a mildly stimulating tonic; but it is exclusively for the sake of its vermifuge properties that it is employed. it appears to hold the place in general estimation in Europe, which spigelia holds with us. At present, however, the active principle santonin is preferred by many, on account both of its vermifuge energy and its want of taste.
Effects of Santonin. From some careful experiments of Dr. Küchenmeister, made upon worms placed in an albuminous liquid, kept constantly at the temperature of 77° F., it appears that an oleaginous solution of santonin killed roundworms sooner than any other anthelmintic, even the most powerful, which he tried. (Arch. Gén., 4e sér., xxix. 206.) It is probable, therefore, that this is one of the most effective of the anthelmintics; but, from its insolubility in water, it should be administered dissolved in oil.
It is related of a family, consisting of two parents and several adult children, that, after they had taken, each one of them, a large dose of wormseed for the expulsion of worms, they were all affected with a morbid condition of vision, in consequence of which colours appeared changed to them; the red, for example, into orange, and the blue into green; and this effect did not cease till the following day. (Ann. de Thérap., 1857, p. 234.) Dr. Thos. Bishop, writing from Naples in reference to the effects of santonin, states that he has found it a most efficient remedy for the Ascaris vermicularis, and that, in the ordinary dose, it produces no other unpleasant effects than occasionally to cause all things to assume a green or greenish-yellow colour, for an hour or two after its administration. (Med. Times and Gaz., July, 1856, p. 22.) A change of the colour of the urine, under the use of santonin, to green or orange-yellow, has been noticed in several instances. (Arch. Gén., Oct. 1858, p. 492.) This effect of santonin in causing objects apparently to change colour, generally becoming yellow, but also green, and sometimes blue, is now established, as well as the change of the urine under its influence to yellow or green. So rapidly is the urine affected, that the altered colour has been noticed 16 minutes after the taking of the medicine. The probability is that santonin undergoes the same alteration in the blood as when exposed to sunlight, and that the new colouring matter resulting from its decomposition affects the colour of objects by being thrown out into the humours of the eye, as it does that of the urine by passing out along with it from the kidneys. it was at one time supposed that santonin was poisonous in over-doses; but it was ascertained that, in an instance in which it was thought to have produced poisonous effects, these were actually owing to strychnia mixed with it; and at present it is believed to be innocent in any dose in which it is likely to be administered. it is asserted, moreover, that the volatile oil of santonica really is poisonous in over-doses; and the probability is that, whatever violent effects may have followed the use of large quantities of the Levant wormseed, were in fact the result of the volatile oil. As to the effects of santonin on the system, they do not seem to have been satisfactorily determined. With little effect on the circulation or the digestive organs, it is believed to act mildly as a diuretic, and has been supposed to exercise a very slight narcotic influence. (For references, see the U. S. Dispensatory.) it is said to have proved useful in amaurosis; but it is almost exclusively used as an anthelmintic.
The dose of santonica in substance is from ten to thirty grains, repeated in the same manner as spigelia. Of santonin two or three grains may be given twice or thrice daily. Three grains are said to have produced alarming symptoms in a child four years old; though some doubt may be entertained on this point. For a child one-third of a grain has been recommended twice a day. From 2 to 5 grains may be dissolved in a fluidounce of castor oil, and a teaspoonful given for a dose. Dr. Bishop, before referred to, gave from one to three grains to children under five years of age, and from five to eight grains to adults.