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DOSAGE OF MEDICINES.
The Doses given throughout this book are for adults; for children the following rule (Young's) will be found the most convenient. Add 12 to the age and divide by the age, to get the denominator of a fraction, the numerator of which is 1. Thus, for a child two years old, 2+12 - = 7, and the dose is one-seventh of that for an adult. Of powerful narcotics scarcely more than one-half of this proportion should be used. Of mild cathartics, two or even three times the proportion may be 'employed.
Children bear Opiates badly:-but on the other hand they stand comparatively large doses of several other drugs; such being Arsenic, Belladonna, Calomel, Ipecacuanha, Squills, Rhubarb, and several other purgatives.
For Hypodermic Injection, the dose should be two-thirds or three-fourths of that used by the mouth; by rectum five-fourths of the same. Strychnine acts more actively when given per rectum than by the stomach.
Conditions which modify the action of medicines, and therefore affect their dosage, are-age, body-weight, temperament and idiosyncrasy, drug-habits, intervals between doses, time of administration, condition of the stomach, temperature of the body, cumulative drug-action, mode and form of drug-administration, disease, climate, race, etc.
The Dosage of Medicines is the weakest part of the therapeutic armament, the flaw in our weapons which may be the cause of their failure at any moment, perhaps the most critical one for a life. If the accumulated rubbish of ages, which has been called therapeutical knowledge, is ever to be given scientific shape, ever placed in process of becoming a science, the question of dosage must form one of the principal corner-stones in the foundation. Drugs have widely differing actions on the human organism in health and in disease, according as they are administered in different doses, in different menstrua, and during different conditions of the subject's health. This difference, when between extremes of dosage, is often so wide as to separate actions directly contrary to each other,that of the very large one opposing the action of the very small dose:-a truth hidden by one set of dogmatists under their former "doctrine," now "rule," of "similars," and avoided by the great mass of the medical profession, through dread of the bogy-name, "irregular."
A thoroughly-prepared materia medica of half-a-dozen standard drugs, such as Aconite, Arsenic, Belladonna, Mercury, Opium and Quinine,-based upon their actions and uses in different doses and under different states of the organism,-would be of more real value to the physician, who wishes to do his work accurately and with his eyes open, than all the contents of the dispensatories, plus the entire literature of the "new remedies," and every symptom in the ten quarto volumes of the largely discredited and partly repudiated homoeopathic Materia Medica.
If our medical students would each devote but one month, of his annual college vacation, to the personal investigation of some one feature of the action of some one drug, under such safe-guards against error as would secure the acceptance of the resulting observations, what a mine of therapeutic gold would soon yield its solid truth to eager eyes! Formally laid down by Haller (see ante, page 18) in 1755, cultivated to some extent by Alexander in 1768, Crumpe in 1793, Thommassini, Curtis, etc.,-urged by John Hunter, Sir Thomas Watson, Dr. King Chambers, and many other luminaries of the medical profession,-the scientifically guarded proving of drugs on the human organism has lain, like the similar work of Jenner, neglected all these years, waiting for another Koch, to re-inaugurate the work.
MATERIA MEDICA AND THERAPEUTICS.
ABRUS, Jequirity (Unofficial), -is the seed of Abrus precatorius, or Wild Liquorice, a plant of the nat. ord. Leguminosa, indigenous in India, but growing wild in most tropical countries. The seeds are small, hard, of a bright scarlet color, with a black spot around the hilum, and contain an alkaloid, some fixed oil, sugar, a principle resembling Glycyrrhizin, and Abric Acid, C12HNO; but neither of these is believed to be the active principle.
Infusum Abri, Infusion of Jequirity (Unofficial),-prepared by macerating three powdered seeds in 3 ss of cold water for twelve hours, adding 3ss of boiling water, and filtering when cold. It should be used while fresh, as after two or three days it is worthless.
Another formula contains gr. ix of Jequirity to the 3, with gr. iv of Boric Acid to prevent decomposition.
PHYSIOLOGICAL ACTION AND THERAPEUTICS.
Jequirity seeds, when moistened with water, become highly poisonous. If applied to the conjunctiva, a severe inflammation is set up, with oedema and false membrane, ulceration of the cornea, and extension to the lids, face, neck and submaxillary glands. Inserted into a wound in cattle, they cause death in a few hours. The irritant action is believed to result from the presence in the seeds of some ferment, or perhaps great numbers of gonidia, which develop rapidly on a suitable tissue. The infusion, in a short time, swarms with bacteria.
Jequirity is used for the purpose of producing a purulent or croupous conjunctivitis, by which to destroy old granulations (trachoma) and panA mild infusion is applied to the eye two or three times a day for two days, and followed by weak solutions of Alum or Borax. This should be repeated after three weeks if necessary. An emulsion of the seeds in water is a useful application to unhealthy ulcers and lupus.
ABSINTHIUM, Wormwood, the leaves and tops of Artemisia Absinthium, a perennial garden herb of the nat. ord. Compositæ, indigenous in Europe, but cultivated in the United States. The leaves are about 2 inches long, hoary, silky-pubescent, petiolate, pinnately two or three-cleft; heads numerous, with small, pale-yellow florets, odor aromatic, taste persistently bitter. It contains a volatile oil and a bitter principle, Absinthin. Dose, gr. xx-xl, in infusion. There are no official preparations, except Vinum Aromaticum (see ALCOHOL), of which Absinthium constitutes one per cent.
Absinthe, the French liqueur, is an alcoholic solution of the oil, containing also extracts of Anise, Marjoram, and Angelica. Its continued use produces various nervous symptoms, morning nausea and vomiting, also a tendency to epileptiform convulsions.
The bitter constituent of Absinthium is stimulant to the digestive organs, but the oil is a narcotic poison, increases the cardiac action, and produces tremor, stupor, epileptiform convulsions, involuntary evacuations, and stertorous breathing. It is but little used in medicine, and only as a stomachic tonic in dyspepsia.
ACACIA, Gum Arabic,—is a gummy exudation from Acacia Verek, a small tree of the nat. ord. Leguminosa, indigenous in Africa-also from other species of Acacia. It occurs in spheroidal tears of various sizes, breaking with a glassy, sometimes iridescent fracture; insoluble in alcohol, but soluble in water, forming a thick and mucilaginous liquid. It consists of Arabin or Arabic Acid, C2H22O11, combined with calcium, potassium, and magnesium.
It should not be prescribed Dose, indefinite.
Mucilago Acacia,-has of Acacia 34, Water to 100 parts. with tinctures or spirits except in very small quantity. Syrupus Acacia,-has of the Mucilage 25, Syrup 75. Should be freshly made. Dose, indefinite.
Acacia enters into the composition of Mistura Amygdale, Mistura Glycyrrhizae Composita, Pulvis Crete Compositus, Trochisci Cretæ, Trochisci Cubebe, and Trochisci Glycyrrhizæ et Opii.
Gum Arabic has no activity except the negative one of a demulcent, and is chiefly used in coughs, sore throats, catarrhal inflammation of the stomach and intestines, and irritant poisoning. It is much employed in pharmacy to suspend insoluble powders in mixtures, for which purpose the mucilage is generally used.
ACETANILIDUM, Acetanilide,-Antifebrin. Like the major number of the newest antipyretics, which are related either to Chinoline or to Phenol, Acetanilide is a derivative of Anilin, from which it is obtained by the action thereon of glacial acetic acid, substituting the organic
Chemically, it has the name
radical Acetyle for an atom of hydrogen.
The name Antifebrin is copyrighted by its original promoters for trade purposes, and therefore should be dropped from professional usage.
It is a pure white and crystalline powder, of neutral reaction, odorless, but of slightly burning taste. It melts at 235° F., and distils at 557° F., -is soluble freely in alcohol, wine, etc.,--but very sparingly (1 in 200) in cold water, and more readily in hot water. It is a neutral substance, being unaffected by hydrochloric or sulphuric acids, and ordinarily so by alkalies.
The dose ranges from gr. ij to gr. x, repeated twice, and not exceeding gr. xlv in the 24 hours. As much as 3j has been swallowed without ill effects supervening. It may be administered in the very convenient form of compressed tablets;-also in powders, or in dilute alcoholic solution. 3j may be dissolved in 3ivss of brandy, to which, if we add 3 vj each of simple syrup and water, we get a six-ounce mixture, of which a tablespoonful (ss) contains 5 grains of Acetanilide, a fair adult dose. As an antipyretic, gr. iij may be administered every 4 to 1⁄2 hour, until 12 or 15 grains have been given, which will usually be a sufficient quantity, especially if given at the acme of the febrile
UNOFFICIAL DERIVATIVES AND ALLIED COMPOUNDS.
Antikamnia is a proprietary preparation widely advertised as an antipyretic and analgesic, of equal power in the latter respect with morphine. Analyses of several samples have been made by different chemists, all of which agree in finding the chief ingredients to be Acetanilide and Sodium Bicarbonate in varying proportions. By some observers Caffeine was detected, also Tartaric Acid, etc. The preparation is formulated by the earliest analysis as a mixture of Acetanilide 70, Sodium Bicarbonate 20, and Caffeine 10 parts., Dose, gr. v-xv.
Antinervine is a mixture of Acetanilide, 2 parts, with 1 each of Ammonium Bromide and Salicylic Acid (Ritsert). It is also called by the names Salbromalide and Salicylbromanilide.
Phenolid is a preparation consisting of a mixture of Acetanilide 58, and Sodium Salicylate 43. It competes with Antikamnia as a universal panacea against pain.
Exodyne is a mixture of Acetanilide 90, Sodium Salicylate 5, and Sodium Bicarbonate 5. The name (from 'εž, out of, odevn, pain) sufficiently states its claims to medicinal virtue.
Exalgine, Methyl-acetanilide,—is a crystalline compound allied to Acetanilide, occurring in acicular needles, readily soluble in dilute alcohol, less so in warm water, and with difficulty in cold water. Dose, gr. j-v, in wine, or other dilute alcoholic mixture. Alcohol 3 ss, and Water 3j form a permanent solution with gr. xvj.
Exalgine resembles Acetanilide and Antipyrine in its antipyretic and analgesic powers. Compared with the latter it is less efficiently antipyretic, but more powerful as an analgesic and antiseptic. In overdose it is highly dangerous, having produced symptoms resembling those of angina pectoris, also toxic effects resembling those of carbolic acid, with delirium, dyspnoea, cyanosis and renal disturbances. It has been used with most excellent results in neuralgias; also in chorea. In the latter affection daily doses of 3 grains were sufficient. Its name, derived from 5, out of, aryos, pain, denotes its principal therapeutic action.
Acetanilide is a very efficient antipyretic, besides being strongly analgesic and antispasmodic, lessening the reflex action of the spinal cord, and inhibiting the sensibility of sensory nerves. It raises the arterial tension somewhat, and slows the heart in a corresponding degree.
Compared with the action of Antipyrine, the effect of Acetanilide on the body-temperature is manifested more slowly (1 hour against 1⁄2 hour), -but lasts a longer time (6 against 2 hours). It is markedly diuretic, somewhat diaphoretic; is a cerebral, muscular and vaso-motor stimulant, and leaves no ill after-effects;-while Antipyrine is powerfully diaphoretic, a cerebral sedative, and produces great depression. Furthermore, Acetanilide produces the same degree of reduction of body-temperature as Antipyrine, with the ingestion of but 4th the dose; and, like the latter agent, it has little or no effect on the normal temperature, and its continued use begets tolerance of its action.
Its Antipyretic action corresponds, in degree and in duration, to the size of the dose, -the pulse is slowed, and quiet sleep often follows. There is neither vomiting nor diarrhoea afterwards, but there is a tendency, in some few cases, to collapse, with chills and cyanosis, especially the latter, during the period of depressed temperature.
A toxic dose destroys the ozonizing function of the blood, decolorizing it, and forming methyl-hæmoglobin. The heart, liver and kidneys are found in a state of acute fatty degeneration, in animals poisoned thereby. Its continued use in large doses is highly injurious to the blood, especially in diseases (as typhoid fever) which are themselves destructive to the blood-elements.
Besides being one of the most efficient antipyretics, this drug has marked analgesic and antispasmodic powers; and these, together with its great advantages of a small dose, efficiency and safety, and the absence of the severe rigors and cardiac depression which mark the chinoline derivatives, combine to make it one of a wider therapeutical range than most of its analogues. It is especially useful in phthisis and typhoid fever, for the hyperpyrexia, thereby relieving wakefulness, lessening delirium, and upholding a failing heart; but if long used in large doses in the latter disease it may increase the liability to serious sequelæ, especially periostitis of the ribs, gangrene of tissues, etc. For the pains of locomotor ataxia, and in those of rheumatic origin, sciatica, lumbago, etc., it is a most efficient remedy. In acute rheumatism, it is highly praised; and in acute bronchitis doses of four grains every two hours have often arrested the attacks within twenty-four hours. In epilepsy, it is being tried, with the view of moderating reflex excitability. Added in minute proportion to aqueous solutions for hypodermic use it is said to preserve them from decomposition more efficiently than any other agent hitherto employed for that purpose.