This section is from the book "A Text-Book Of Pharmacology, Therapeutics And Materia Medica", by T. Lauder Brunton. Also available from Amazon: A text-book of pharmacology, therapeutics and materia medica.
A non-metallic element obtained from bones.
Characters. - A semi-transparent, yellowish, waxy-looking solid. When exposed to air it emits white fumes which are luminous in the dark and have a garlicky odour.
This is evaporated and distilled with charcoal, which removes the oxygen. The phosphorus distils over and is condensed under water.
Pilula Phosphori (1/30 gr. in 3 grs.) (p. 522).....................................................................
Pilulae Phosphori (1/100 gr. in each) (p. 523)....................................................................
Oleum Phosphoratum (with stronger ether and almond oil 1 per cent.) ...........................
Action of Phosphorus. - Living protoplasm has the power of oxidising all the members of this group, and also of reducing the products of their oxidation (Binz). It is probable that this action goes on more easily with phosphorus than with nitrogen. Hence if phosphorus replaces nitrogen in a living cell it will quicken metabolism. It is absorbed unchanged into the blood, and is excreted by the kidneys either as phosphorus or phosphoric acid. In small doses it appears to cause development of the fibrous tissue in the liver, and in doses too small to affect the liver or stomach it acts upon the osseous tissues. Its action upon the bones is somewhat peculiar, and has been fully investigated by Wegner. When phosphorus is given to growing animals the bone as it develops is denser than usual, the cancellous tissue being like the denser tissue in the long bones. Cancellous tissue formed before the administration of phosphorus remains unchanged. If the administration be still continued, the cancellous tissue formed previously to the use of the drug is absorbed, and serves to form the cavity of the bone, and after a while the normal cancellated tissue at the end of the epiphysis is also replaced by solid bone. Afterwards even the dense bone thus formed becomes absorbed, and forms the cavity of the long bone. In adult animals phosphorus also causes the bones to become denser, and this is especially noticeable in chickens, in which the cavity of the bone may be completely filled up, so that long bones form a solid rod instead of a tube. The influence of phosphorus upon osseous tissues is not due to excess of phosphates produced by it in the blood, but to stimulation of tissue-growth itself by the phosphorus, for Wegner found that in animals fed with phosphorus but almost entirely deprived of phosphates, the same dense, bony substance was formed, except that instead of the bone being hard, it was like that which occurs in rickets. In men and women exposed to the fumes of phosphorus, e.g. those employed in the manufacture of lucifer-matches, caries of the lower jaw is a frequent occurrence. This is not due to the action of the phosphorus after absorption into the circulation, but to the direct effect of the fumes upon the bone itself. For it has been found that when a bone of an animal fed by phosphorus was exposed, no carious change took place; but if one were exposed to the fumes, caries was produced, and amongst lucifer-match makers it has been noticed that only those who have carious teeth suffer from necrosis of the jaw. "When doses larger than those which induce induration of the bones are given, the phosphorus appears to act upon the connective tissue of the stomach and liver, causing chronic inflammation of these organs, and atrophy of the secreting cells, so that cirrhosis of the liver appears. In poisonous doses phosphorus first produces the symptoms of gastro-enteritis, with a garlicky taste in the mouth, the vomited matters having a similar odour, containing bile, and, but rarely, blood. They sometimes shine in the dark. At the end of twenty-four to thirty-six hours, the symptoms of gastrointestinal irritation cease, and the patient is apparently well with the exception of vague pains in the limbs and loins. During this period, however, fatty degeneration of the liver, stomach, and kidneys is going on, and the effect of the changes in these organs soon manifests itself. Sometimes, after two or three days, the patient may die suddenly, without exhibiting any fresh symptoms, but usually, on the second or third day, jaundice appears, while the urine contains bile, and often albumen, leucin, and tyrosin. There is occasionally vomiting and purging, headache, sleeplessness, delirium, and coma, and death with or without convulsions. In some cases, when the poisoning runs a less acute course, the effect of fatty degeneration of the vessels is most prominent, discharges of blood occurring from the stomach, intestines, nose, lungs, bladder, uterus, and ears, and ecchymoses appearing on the surface. Increasing anaemia and debility finally kill the patient.
The treatment in cases of poisoning by phosphorus is to wash out the stomach freely by means of the stomach-pump, or to employ it by an emetic of sulphate of copper, and to give oxidised oil of turpentine in 40-minim doses in mucilage every fifteen minutes for an hour. Fats and oils should be withheld, as they dissolve any phosphorus which may be present in the stomach, and assist its absorption.
The fatty degeneration produced by phosphorus appears to depend on a more rapid splitting up of albuminous tissues, along with deficient oxidation. This was shown by Voit and Bauer, who produced fatty degeneration of the organs by the administration of phosphorus in dogs absolutely deprived of food, where the fat found after death could neither have come from food nor from fat deposited in other parts of the body, as this had all been absorbed before the administration of the drug had been commenced. It must therefore have been formed in situ from the [decomposition of albuminous substances, and these were shown to have split up more quickly than usual by the amount of urea in the urine being increased by the phosphorus, while oxidation in the body was shown to have diminished by the amount of oxygen absorbed and carbonic acid given off being lessened. In man, the products of albuminous waste are often not converted into urea, but appear in the urine as leucin and tyrosin.
The action of compounds containing phosphorus appears to depend considerably on the more or less complete saturation of its affinities, and the readiness with which the phosphorus may attach itself to the organic constituents of the tissues. Thus, phosphoric acid, in which the affinities of the phosphorus are fully saturated by oxygen, appears simply to act as an acid without exerting any specific action, and when combined with sodium, its effects are simply those of a neutral alkaline salt.
Metaphosphoric and pyrophosphoric acids appear to have a specific poisonous action more nearly resembling that of phosphorus. Pyrophosphate of sodium paralyses the nerve-centres in the spinal cord and medulla oblongata, producing drowsiness, loss of reflex action, paralysis, and death, which is sometimes preceded by convulsions. It lowers the blood-pressure in mammals, slows the beats of the frog's heart, renders them powerful and finally arrests them in systole. When death does not occur rapidly, marked fatty degeneration of the heart and kidneys is found, and a similar change takes place, though to a less extent, in the liver. Although it acts as a poison when injected subcutaneously or into the circulation, pyrophosphate of sodium has no poisonous action when taken into the intestinal canal.
Metaphosphate of sodium has a similar but less powerful action.
Uses. - Phosphorus forms an important constituent of nervous tissue, and has been employed in cases of nervous debility, neuralgia, wakefulness, paralysis, locomotor ataxia, and impotence. In some cases of leucocythaemia it is useful. It has been used in osteomalacia, and instead of arsenic in skin-diseases (vide also p. 719). Even in small doses it may cause nausea, with unpleasant eructations. It is well, therefore, to commence with a very small dose, such as 1/100 of a grain.