PARALDEHYDE. — Paraldehyde (pa raldehydum, U. S. P.) is a polymeric form of ethylic aldehyde. It occurs as a colorless liquid (crystallizes below 50.9° F.), having a peculiar, aromatic, suffocat ing odor and warm taste. It is soluble in alcohol, ether, oils, and chloroform, and in S to 10 parts of cold water, but less readily in hot water. When small bulk is desired, it may be given in an equal volume of oil of sweet almonds. The dose is 30 to 90 minims in capsules, or well diluted with simple elixir, sweet ened water, brandy, or rum.
Physiological Action.—The weight of evidence tends to sustain the views of who in a series of experiments found that paraldehyde was mainly elim inated by the lungs, being readily de tected in the breath six or eight hours after its ingestion. In the urine it can also be recognized three or four hours after ingestion. The drug markedly in creases the elimination of urea, accom panied, however, by increase of the watery constituents. Small doses pro duced no fall of arterial pressure in cats and rabbits, but large doses caused a con siderable fall. In man it also lowers heart-pressure. Injected intravenously it soon caused death through heart-de pression, after a gradual increase of the pulsations. Paraldehyde depresses reflex action and reduces muscular tetany.
Poisoning by Paraldehyde.—Thomas MacKenzie, of Douglass, England, re cords (Brit. Med. Jour., Dec. 12, '91) a case of poisoning by paraldehyde, in a woman who took 3 7, ounces. Several hours after the drug was taken she was found in a deep stupor and limp, like one under the influence of chloroform, with a strong odor of the drug on her breath, face slightly flushed, pupils moderately contracted and quite insensible to light; pulse, 120; respirations, 40. Notwith standing every means was used to arouse her, it was forty-one hours from the time the drug was taken before she was suffi ciently aroused to understand and answer simple questions. When death occurs, it is from respiratory failure. It is not so depressant to the heart as chloral.
Paraldehyde Habit.—Several cases of the paraldehyde habit arc on record, and the results, physical and mental, have usually been most wretched, where the habit was kept up for a long time.
Case of paraldehyde habit in which the woman had taken 1-ounce doses nightly for months, and, instead of suffering ill effects, had grown fat. Frederick Peter son (Med. Rec., Dec. 10, '92).
Report of a case in which patient was accustomed to take 16 ounces of paralde hyde weekly. Patient became rapidly emaciated, suffered great cardiac and general muscular weakness, and subse quently had delusions of persecution with mental failure. Complete recovery followed restraint and appropriate treat ment after three months. F. A. Elkins (Quar. Jour. of Inebriety, Oct., '94).
Symptoms resembling those of chronic alcoholism generally follow the tinued use of the drug in large doses.
Krafft-Ebing has observed epileptoid convulsions in these cases.
Case of paraldehyde delirium tremens in a man, 41 years of age, who tak ing 2 ounces of this drug each day. He could stand with difficulty, and, although his intelligence was not impaired, his speech was labored, and words were de livered in syllables in order to improve this deficiency. His nutrition was en feebled, skin pale, and brow covered with perspiration. The eyeballs were deeply sunken, without disturbance of motion, and his look was fixed. Pupils were in middilatation, but reacted well to light. There were no painful points on head or spine. There was marked tremor of hands and tongue, and the latter was coated. Spinal innervation was un changed. The lungs showed marked em physema; apex-beat was absent; heart sounds muffled; pulmonic second sound accentuated; pulse slightly irregular, ninety to the minute, and moderately full. Abdomen was retracted. Urine was very acid, contained a large quantity of urates, of specific gravity of 1030, but free from albumin and sugar. Patient was sleepless, became delirious, had ideas of persecution and hallucinations, but improved under sodium bromide and tri onal, and finally was discharged after sixteen days of observation. G. Rein hold (They. Monats., II. 6, S. 3110, '97).