Physiological Action (Internal)

Circulatory System

In accordance with the slight general excitation already described, the pulse and temperature are slightly raised about an hour after taking doses of 1/30 gr.; and after such doses, given daily for some weeks, the circulation has been found more equable and more steady than before (Dr. Ford on fifteen patients: American Journal of Insanity, January, 1874). Thompson has noted dilatation of the skin-capillaries. In toxic cases the pulse rises to 120 or more per minute, and the temperature to 102° to 103° F., though this condition is only temporary.

Dr. Gowers has proved that, under the influence of small, continued doses, the proportion of red blood-corpuscles is increased (British Medi-cal Journal, i., 1878), at least in lymphoma, and this interesting observation may throw light on the tonic power of the drug.

Toxic Action

The poisonous symptoms produced are essentially of irritant and destructive character, but vary in degree, and are often obscure and insidious - probably in proportion to the varying amount absorbed, or the chemical changes the drug undergoes under different circumstances. Lecorche makes three forms of "acute phosphorismus": 1, that produced by phosphuretted hydrogen; 2, that by phosphoric acid; 3, a mixed form; but the clinical varieties described by Trousseau, or better by Dr. Guy, are of more practical importance - he names them as 1, the irritant; 2, the nervous; and 3, the hemorrhagic form - and a brief notice of them comes within the scope of our subject, because it will help to fix in the mind of the reader the characters of the full physiological action of the drug.

1. The irritant form is the most common: it is induced (on the Continent, not infrequently) by swallowing match-heads, or a certain rat-poison paste. A foul taste and smell, like garlic or sulphur, are first perceived, then heat and swelling of the tongue and fauces, pain and distension of the stomach, bilious and mucous vomiting and purging, with colic and abdominal tenderness. The ejecta occasionally contain blood, and may be phosphorescent, and the faeces contain small masses of crystals of the fatty acids, and later in the attack become clay-colored. The pulse rises to 120 or higher, and the temperature to 102° or 103° F.; but this pyrexia passes away as the gastro-intestinal symptoms become very severe, and is succeeded by an opposite condition (Gubler).

In the early stages there is pronounced nerve-excitement, with hyperaesthesia, agitation, talkative delirium, and delusion, which is sometimes of erotic character, though priapism is rare. Muscular twitchings and cramps, and even general convulsions occur, but later on follow prostration, fainting, and collapse, loss of muscular sense, and of sensation, retention of urine, and partial paralysis, affecting mostly the extensor muscles.

2. In the nervous form these latter symptoms become much more marked, but there is little pyrexia; erythematous spots occur in the skin, which is dry and yellow, and later becomes cold; dilatation of pupil and strabismus are described, and the fatal termination comes on with somnolence and coma.

3. The hemorrhagic form is less quickly fatal than the others. In it the ejecta are almost wholly sanguineous; bleeding occurs in and from the skin and mucous membranes, and many parts of the body. It is due partly to the altered blood-state, and partly to general softening of the tissues, including fatty degeneration of vessels (Lebert). In women there is uterine hemorrhage, miscarriage, or abortion - but these may be due to the irritant effects on the intestinal canal.

In all cases of phosphorus-poisoning, about the third or fourth day pain is felt over the liver, and is followed shortly afterward by jaundice, headache, and sleeplessness; the urine is found to contain bile, and generally albumen, leucin, tyrosin, and paralactic acid. The presence of bile is an argument that the jaundice depends not on suppression, but on occlusion of the biliary passages, which is probably catarrhal in character. In exceptional cases (in which, probably, only a small amount of the poison has been absorbed) there has been neither gastro-enteritis, nerve-excitement, nor quick pulse, but the prominent symptoms have been jaundice and hepatic congestion (British and Foreign Review, April, 1863). The time that elapses from the taking of the phosphorus to the appearance of symptoms varies from a few minutes to two days. Death, when it occurs, is usually from asthenia, but the course of the illness is not always steadily progressive: sometimes the severe symptoms subside for a few hours or days, and death takes place suddenly, from failure of the cardiac muscle (Habershon: Medico- Chirurgical Transactions, v., 50). A fatal dose may be stated as about 1 to 2 gr. for adults, but much less for children, in whom vomiting and convulsions are usually the prominent symptoms.

Tolerance

The system may become habituated to the use of phosphorus to some extent, and a gradual increase of dose may be borne up to an amount which would not at first be tolerated. In using it for neuralgia, Thompson has found that cases not relieved by a gradually increased dose have yielded to a similar dose, given at once after allowing an interval to elapse. Any "cumulative action," so called, may be explained by the mechanical accumulation of the drug in the stomach or intestines.