An alkaloid obtained from the bark of various species of Cinchona.

Properties : Quinin occurs as white, flaky or microcrystalline powder, odorless and having a bitter taste. It is very slightly soluble in water (1 :1,750), but very soluble in alcohol (1 :0.6).

Action and Uses: Quinin is antimalarial, antipyretic, ecbolic and is also used as a bitter tonic. Quinin is a protoplasmic poison, especially affecting the protozoa more than bacteria. It is somewhat irritant to the stomach and intestines and when absorbed it causes ringing in the ears, but in moderate doses produces no other marked effects in healthy persons. In patients with fever it is antipyretic. Its solutions produce local anesthesia, especially the solution of quinin and urea hydrochlorid. In large doses it produces depression of the heart and respiration, and collapse. In toxic doses quinin may produce" more or less complete hemianopia terminating in permanent loss of sight. Moderately large doses of quinin act as a stimulant to the uterine muscles, but do not produce such spasmodic contractions as ergot.

Quinin may be used as a tonic, like the simple bitters, for the improvement of digestion and nutrition.

Its chief use is as an antiperiodic in malaria. In this disease it should be given in large doses several hours before the time of the expected chill.

Dosage: 0.25 gm. or 4 grains. In malaria 0.6 gm. or 10 grains may be given at a dose. For ordinary use it is preferably administered in the form of capsules. For use as a bitter tonic it is given in solution. For its use as a local anesthetic see quinin and urea hydrochlorid. In medicine quinin is customarily used in the form of one of the official or unofficial salts.

The intensely bitter taste of quinin and its soluble salts, which constitutes the greatest objection to its use, especially with children, may be masked by administering the alkaloid or the insoluble tannate in syrup of glycyrrhiza or syrup of yerba santa.

Quininae Bisulphas.—Quinine Bisulphate, U. S. P. The Acid Sulphate Of The Alkaloid Quinin.

Properties : Quinin bisulphate occurs in colorless, transparent crystals or as small whitish needles, odorless and having a very bitter taste. It is freely soluble in water (1:8.5) and soluble in alcohol (1 :18).

Dosage: 0.25 gm. or 4 grains.

Quininae Hydrochloridum.—Quinine Hydrochloride, U. S. P.

Properties : Quinin hydrochlorid occurs as white silky, glistening needles, odorless and having a very bitter taste." It is soluble in water (1 :18> and very soluble in alcohol (1 :0.6).

Dosage: 0.25 gm. or 4 grains.

Quininae Sulphas.—Quinine Sulphate, U. S. P.

Properties : Quinin sulphate occurs as white, glistening crystals of prismatic needles, odorless and having a very bitter taste. It is only slightly soluble in water (1:720). but soluble in alcohol (1 :86).

Dosage: 0.25 gm. or 4 grains.

Quininae Tannas.—Quinine Tannate, N. N. R.

The tannate of the alkaloid quinin, containing from 30 to 35 per cent, of quinin

Properties : Quinin tannato occurs as an amorphous, pale lemon-yellow, odorless powder without taste, or at most slightly bitter, with scarcely an astringency. It is only slightly soluble in water, but freely soluble in alcohol (1:3).

Dosage: 0.5 gm. or 7 grains.

Quininae Et Ureae Hydrochloridum.—Quinine And Urea Hydrochlorid, N. N. R.

The compound of quinin hydrochlorid and urea hydrochlorid, containing approximately 60 per cent, of anhydrous quinin.

Properties : Quinin and urea hydrochlorid occurs as white. interlaced prismatic crystals, odorless and having a very bitter taste. It is freely soluble in water (1 :1).

Actions and Uses : Quinin and urea hydrochlorid has the actions of quinin. It is non-irritating when injected hypodermically. Recent investigations have shown that when injected hypodermically or when applied locally to mucous membranes, it exerts an anesthetic action similar to that of cocain. It is reported that the anesthesia is in some cases prolonged for several days.

Quinin and urea hydrochlorid is especially useful in the treatment of malaria by hypodermic injections. It has also been applied as a substitute for cocain in the production of local anesthesia.

Dosage: The same as quinin. For the production of local anesthesia, injection of a solution of from 0.25 to 1 per cent, strength is said to bo free from the risk of producing fibrous indurations, which sometimes occur with the stronger solution. For application to mucous membranes solutions varying in strength from 10 to 20 per cent, should be used.