Acidum Noricum.

Synonyms—Picric acid, carbazotic acid, trinitraphenol.

Occurrence—This acid is obtained from the action of creosote upon nitric acid, or by dissolving pure crystallized carbolic acid in sulphuric acid and treating this product with nitric acid or with sodium nitrate.

Description—It is crystalline in character, light yellow in color, bitter, freely soluble in water, sublimes without decomposition, and explodes upon heating. Its salts of potassium and sodium are too unstable for use in medicine, being violent explosives, the ammonium salt alone being in common Use.

Physiological Action—It acts as an irritating depressant. In poisonous doses, there is a reduction of temperature and blood pressure, shallow breathing, rapid, feeble heart action, great weakness, profuse diarrhea with pain in the stomach and bowels, and collapse. In some cases convulsions occur followed by death.

It colors the serum of the blood, materially increases the white corpuscles and alters the character of the red blood cells. The action of the agent as a medicine is considered in the action of the picrate of ammonium.

Therapy—Picric acid is used in the treatment of superficial burns by a number of eminent authorities, but in the treatment of extensive and deep burns, there is danger of poisoning. Sterilized gauze is soaked in a five per cent solution of picric acid and laid over the entire burned surface, a light dressing is laid over this and the whole is retained by a light bandage. After three days it may be thoroughly moistened with a solution of the acid as it will become very dry, and may be removed. A second dressing may be applied as the first. It controls pain and rapidly promotes healing. When granulation is progressing, and pus no longer forms, it may be replaced by a simpler dressing.

In some cases the solution is simply brushed over the surface thoroughly, and gauze placed over it for a few days.

Stains from the use of picric acid may be removed by alcohol, a solution of boric acid, or a strong soap.

The American Materia Medica, Therapeutics and Pharmacognosy, 1919, was written by Finley Ellingwood, M.D.
It was scanned by Michael Moore for the Southwest School of Botanical Medicine.