Part 42

An alkaloid obtained from opium by evaporation of the ammoniacal liquid, after the precipitation of morphine. The residue is added to water, precipitated by potassium hydrate, and redissolved in ether, from which codeine crystallizes out on evaporation.

PROPERTIES.--White or nearly translucent, orthorhombic prisms, octahedral crystals, or a crystalline powder; odorless and having a faintly bitter taste; slightly efflorescent in warm air. Soluble in water, alcohol, ether and chloroform.

DOSE.--Dogs, ¹⁄₄ to 1¹⁄₂ gr.

HEROIN--DIACETYLMORPHINE

This drug is a derivative of morphine, and is now used extensively in human medicine as a substitute for morphine and codeine.

PROPERTIES.--White or colorless, crystalline powder, possessing a slightly bitter taste. Insoluble in water, but readily soluble in weak acidous solutions. Heroin hydrochloride is a white, crystalline powder, odorless, soluble in 2 parts of water. Heroin surpasses both morphine and codeine therapeutically in many ways. It increases markedly the inspiratory and expiratory force, while lessening the number of the respiratory movements and exerts a special sedative influence on the respiratory mucous membranes. The drug acts also as a general motor depressant, hypnotic and analgesic, but is not comparable to morphine in these respects. Heroin is about five times more toxic for dogs than morphine. Heroin is particularly valuable in the treatment of all varieties of coughs affecting the dog. The after-effects of small doses are not as nauseating or constipating as morphine.

Heroin can be given in powder, pill or tablet, the Heroin hydrochloride in solution, every three or four hours.

DOSE OF EITHER.--Horses, ¹⁄₂ to 2 gr.; dogs, ¹⁄₂₄ to ¹⁄₆ gr.

ACTIONS.--Opium is analgesic, hypnotic, diaphoretic, antispasmodic, narcotic; also cardiac and respiratory depressant after primary brief stimulation.

MEDICAL DOSES.--It dries all secretions except the mammae and skin. The latter being increased, it produces dryness of the mouth and throat, arrests gastric secretions, retards digestion and causes anorexia (loss of appetite); it stimulates the brain by increasing the blood supply; in man it stimulates the mental activity, while in animals it stimulates motor activity; it does not affect the conductivity of nerves, but it prevents the consciousness to pain by paralyzing the nerve centers; the action of the heart is increased and arterial tension is raised; the pupil slightly contracted; the mind at first stimulated, becomes calm, sleep follows, disturbed by dreams and headache; constipation and some depression follows.

LARGE DOSES.--Arrest digestion, cause nausea and vomiting, greatly increase perspiration, prevents the conductivity of nerves, depresses the heart and circulation, impairing oxidation and lowering temperature; it contracts the pupil by stimulating the motor nerve of the eye (in horses it dilates the pupil) and causes intense puritis (itching), especially of the nose, often retention of the urine and soon profound sleep; in some cases coma or delirium, leaving as after-effects nausea, depression, constipation, vertigo, anorexia, nasal puritis and fetid pathological secretions.

Morphine and codeine compared with the action of opium. Morphine is more anodyne and hypnotic; it causes more intense puritis (itching) is less stimulant, less convulsant, less constipating and diaphoretic.

Codeine is a motor paralyzant; it exalts the spinal cord more than morphine and affects the cerebrum less, producing muscular tremors in excess of sedation; it reduces the urinary sugar in diabetes and has a selective sedative influence on the pneumogastric nerve, thus a better sedative in cough.

Indications for the use of Opium:

1. To relieve pain and spasm. 2. To produce sleep. 3. To abort inflammation. 4. To check excessive secretions. 5. To act as a stimulant and supporting agent. 6. As a sudorific (not so active in animals as in man).

Sulphuric ether administered with opium prevents its drying up effects as well as the nauseating and depressing effects. Used for pain from any cause except acute inflammation of the brain. Used in low fevers to support the system when sufficient food cannot be taken, also in irritation of bronchi, bladder, stomach and bowels, as well as the uterus.

In inflammation of the serous membranes which line the abdominal walls (peritonitis) opium can be used freely; combined or alternated with aconite and diuretics is very highly recommended and tends to prevent dropsical conditions.

In inflammation of the serous membrane investing lungs and lining the thorax (pleurisy) opium and aconite will often arrest its development if administered in its first stages.

In diarrhoea and dysentery opium is said to be one of the best medicines we have, it can be combined with acetate of lead, prepared chalk, etc.

In inflammation of the bowels, owing to its effect in binding up the bowels, belladonna alternated with aconite is preferred to opium.

In colds administer Dover’s Powder, or opium, ammonium carbonate, quinine sulphate and camphor.

In spasmodic colic do not use opium, but give hypodermically three to four grains of morphine sulphate; it is non-constipating; also use anodynes, such as cannabis indica, hyoscyamus, etc., are preferable.

In gastritis, opium conjoined with bismuth subnitrate and hydrastis.

In eversion of the rectum or uterus, administer morphine hypodermically to prevent straining.

In muscular spasms opium is very effective.

In cerebro-spinal meningitis opium should be administered early, before exudation has set in, with belladonna and ergot, alternated with aconite.

In diabetes mellitus, codeine is said to be best, as it lessens the amount of sugar in the urine and should be administered by the mouth; if given hypodermically it exerts no influence on the sugar.

In catarrhal diseases administer opium to lessen the discharge.