An alkaloid obtained from Opium. C18H21 No3+H2O=316.31. Synonym. - Methyl Morphine.

Source

Obtained by evaporating the ammoniacal liquids, remaining . after the precipitation of Morphine by Ammonia in the preparation of the Hydrochlorate, treating the residue with water, precipitation with Caustic Potash, and purifying by dissolving in Ether and letting the Codeine crystallize out on spontaneous evaporation.

Characters

White, or nearly translucent, orthorhombic prisms, or octahedral crystals, having a faintly bitter taste, and slightly efflorescent in warm air.

Solubility

In 80 parts of water; in 3 of Alcohol.

Dose, 1/4 to 2 gr.; .015 to .12 gm.

Action And Therapeutics Of Codeine

Codeine may produce tremors because it excites the cord more, and depresses the higher faculties less, than morphine, and in man its physiological action is in all respects much less than that of morphine. It often relieves the hacking cough of phthisis. It is also used for ovarian pain and to diminish the glycosuria in diabetes which it does more effectually than opium itself and as an analgesic. It is an excellent substitute for morphine as an ingredient of cough mixture. For diabetes it is usually given as a pill, or in a syrup. The phosphate (not official) has the advantage of being much more soluble than codeine.

The following non-official alkaloids are sometimes used: -

Thebaine. Paramorphine

Thebaine. Synonym. - Paramorphine. It is contained in Opium, 0.15 to 1 per cent. It occurs in silvery scales or hard prisms, odorless and having a bitterish taste; soluble in Ether, Alcohol and Chloroform. This produces powerful convulsions as the result of its action on the cord. Its subsequent depressant action is very slight.

Narceine

Narceine. - It is contained in Opium 0.1 to 0.7 per cent., and occurs in long quadrangular prisms, or white, silky needles, sparingly soluble in Alcohol, and in water. It closely resembles morphine in its action, but is probably more hypnotic and not so likely to be followed by disagreeable after-effects.

Anarcotine

Anarcotine. - This is also known as narcotine, which is an improper name, for the drug does not cause sleep. It is contained in opium 1.3 to 10. per cent., the amount varying greatly according to the source; it is the chief constituent of Indian opium. It exists in a free state in Opium from which it is left behind when the drug is treated with water. It crystallizes in white, silky, flexible needles which are tasteless and odorless. It is antiperiodic in its action and is valuable not only as a preventive, but as well cures malarial fevers.