The fresh gland furnishes 20 per cent. of extract or 27 to 28 per cent. of dry powder. The powder is employed in tablet form, in the dose of of a grain.
A powder that will keep for a long time may be prepared in the following manner: After an aseptic removal of the glands, and removing all foreign tis sues, pulpify and mix them with the biborate of soda and powdered charcoal. In this manner is obtained a dry powder, which is put in capsules, each contain ing Ph grains of the extract. This preparation, when not exposed to heat, is not altered. Vigier (Archives de Neurol., Mar., '96).
A preparation that will also keep a long time is the following: Immediately after the death of the animal the gland is excised under all aseptic precautions, all extraneous tissues are removed, ,and the gland is powdered with boric acid. When a sufficient number have been prepared they are taken to the laboratory, cut up, and triturated with sugar and an addi tional amount of boric acid. The sugar absorbs the juices, and the resulting mixture is almost free from liquid. This mixture is desiccated at a temperature of 86° C., and divided into small masses, which are coated with gelatin, each mass containing about 1 grains.
Each lobe of the thyroid produces about 26.8 per cent. of powder; three capsules are therefore equivalent to one lobe of the gland, or the therapeutic unit. (Yvon.) The thyroid extracts prepared by the pharmaceutical chemists of the United States offer a convenient form of admin istration.
Untoward Effects and their Preven tion.—The dangers attending the use of thyroid preparations depend, to a degree, upon the manner in which the remedy is administered. When the pure gland is used, the physiological phenomena caused by an overdose will show them selves,—namely: a weak, rapid pulse and shortness of breath; vomiting, cardiac oppression, a feeling of tightness around the chest, vertigo, and coma. When dried powder or compressed tablets are used symptoms of ptomaine poisoning may be added to those mentioned.
Too great an increase in the pulse-rate and vomiting are signs that the patient is getting too much. H. W. G. Macken
zie (Centralb. f. Nerv. Psy., July, '93).
In giving thyroid preparations, the best guide is the pulse. Any consider able quickening or palpitation should lead us to discontinue the drug until the cardiac action is again normal. There are no dangers in the use of the drug, provided we begin with small doses, from I to 2 grains of Ameri can extracts, and gradually increase, watching the pulse. It should never be given to a patient who cannot be closely watched. R. C. Cabot (Med. News, Sept. 12, '96).
Case in which a man took for obesity nearly 1000 5-grain tablets of thyroid extract within five weeks. After the first three weeks he began rapidly to develop the symptoms of acute Graves's disease. When thyroid was stopped and patient was put upon arsenic all the symptoms disappeared quickly, excepting the eye changes and the goitre, which were still notable for about six months. A. V. Notthaft (Centralb. f. innere Med., Apr. 16, '98).
Among the less active symptoms are anorexia, diarrhoea, malaise, lassitude, and pain in the extremities; headache, increase of urine, rise of temperature, various eruptions, urticaria, transient and papular erythema and eczema, and, in some cases, nervous manifestations: neuralgia, delirium, convulsions, delir ium of persecution, aphasia, monoplegia, etc.
Some of the discomforts of treatment are a feeling of tightness in the chest, with itching, burning, and other ab normal sensations in the skin, and a sense of weakness. G. Stewart (Practi tioner, July, '93).
Thyroid powder, when given subcu taneously, also produces a rise of tem perature. It is a pyrogenic agent. This action of the thyroid shows that we should be careful in its administration to persons affected with heart disease. Isaac Ott (Med. Bull., Oct., '97).
The drug is badly tolerated by genera] paralytic and tuberculous patients, still worse by patients over GO years of age, and worst of all by fat patients, espe cially those in whom there is reason to suspect fatty degeneration of the heart. C. C. Easterbrook (Lancet, Aug. 27, '9S).