External

The compound with camphor equal weights of camphor and chloral rubbed together to form a liquid has been employed as a local anodyne for neuralgia, and may be applied to aching teeth. To this menthol can be advantageously added.

Internal

Chloral is largely used for its hypnotic effect. Its great advantages over many other hypnotics are that doses sufficient to produce a deep sleep are not large enough to cause gastro-intestinal irritation, cardiac and respiratory depression, and the other harmful effects. Chloral is certain in its action in that it quickly produces sleep; and there are usually no bad after-effects. Chloral is far from being a safe hypnotic; it depresses the heart so markedly that the prescriber should be always upon his guard. Children take it well. Its unpleasant taste can be concealed by administration in bottled "lemon soda."

It is especially useful in simple insomnia from overwork, worry, etc. Its disadvantages are that it does not relieve pain at all, and it should therefore not be used for insomnia due to this cause; and that, as it depresses the heart and respiration, it must be given carefully in diseases of the heart and lungs, and also when the stomach or intestines are diseased, as it may irritate these structures. In febrile insomnia it is very valuable in the early stages, but must be given cautiously, later, when there is any danger of cardiac weakness. It does not relieve the distress and cough of disease of the heart and lungs. It has been used as a cerebral depressant in delirium tremens, puerperal convulsions, and mania, but very large doses are required, and consequently the results must be watched with great care. A very important use of chloral is in midwifery; here it has been designated the medicinal forceps. Frequently after rest has been obtained by this drug, labor proceeds vigorously and is rapidly terminated.

From its action on the spinal cord, chloral has been used, and sometimes with success, in tetanus, whooping-cough, incontinence of urine and strychnine poisoning.

Hypnal is a compound of chloral with antipyrin, made by mixing their solutions, and is obtained in crystalline form. It was proposed by Bardet as a hypnotic, more certain than chloral, nearly free from taste, entirely free from irritating effect upon the mucous membranes, and having distinct analgesic effects. It has been but little used. The dose is about 15 gr.; 1.00 gm.

Toxicology

Acute Poisoning

As will be inferred from the action of chloral, the symptoms of poisoning by it closely resemble those of opium. They are deep coma; a weak, feeble, irregular, slow pulse, which may become quick before death; diminished frequency of respiration and consequent lividity; and abolition of reflex movements. The surface of the skin is cold, and the temperature is subnormal. The pulse should always be carefully watched whenever chloral has been administered. It frequently happens that symptoms of failing heart come on unexpectedly even after small doses.

Treatment

Give emetics (see p. 139) or wash out the stomach. Keep up the temperature by hot bottles, hot blankets, friction and massage. Prevent sleep by the injection of hot, strong coffee into the rectum, shouting at the patient, hitting him, flapping with wet towels, bathing, etc. Give a subcutaneous injection of strychnine, because of its stimulant action on the anterior cornua. Use inhalations of amyl nitrite to stimulate the heart, and artificial respiration if necessary.

Chronic Poisoning

The taking of chloral is a vice to which many persons are addicted. A craving for it is soon established. The chief symptoms of chronic chloral poisoning are gastro-intestinal irritation, a great liability to erythematous eruptions, dyspnoea dependent upon the cardiac and respiratory depression and general weakness. There may be disturbance of the mental equilibrium, and persons have been known to become permanently weak-minded. A slightly larger dose than usual may be quickly fatal.