Properties : Sodium bicarbonate occurs as a white, opaque powder, odorless and having a cooling, mildly alkaline taste. It is soluble in water (1:12) at 15 C, practically without decomposition, but above this temperature the solution gradually loses carbon dioxid, and at the boiling point of water the salt is converted into normal carbonate; it is practically insoluble in alcohol.

Incompatibilities : Sodium bicarbonate is incompatible with acids and acid salts, and the solution should be made with cold water, which tends to prevent its conversion into the more alkaline carbonate.

Action and Uses: Sodium bicarbonate is used to neutralize the acid of the gastric juice in hyperacidity, acid dyspepsia, etc. For this purpose it is to be preferred in cases which are not accompanied by constipation or in which there is diarrhea. It is sometimes used to render the urine alkaline in gravel, etc., but the citrate is preferable.

Large doses are given by the mouth in cases of acidosis in diabetes, fevers and similar conditions. Sodium bicarbonate may be used intravenously in cases of extreme acidosis. It may also be employed with sodium chlorid for saline infusions in cases accompanied by edema, although edema produced by large doses of alkali has been reported. It should never be injected hypodermically or intramuscularly as it may cause sloughing.

Externally it is used as a mild alkaline wash. Solutions of sodium bicarbonate are antipruritic. A weak solution is employed to soften impacted cerumen. Sodium bicarbonate may be employed to neutralize acetic or citric acids for the extemporaneous preparation of sodium acetate or citrate.

Dosage: 1 gm. or 15 grains. Much larger doses may be given in acidosis. As much as 60 gm. or 2 ounces may be given daily. It may be administered by a "drop enema" of a 4 per cent, solution. For intravenous injection a 6 per cent, solution sterilized by boiling and hence partly converted into the carbonate has been recommended. 1,000 c.c. of such a solution may be injected, but great care must be taken that none of the liquid gets outside the vein lest necrosis of the tissues occur.