POTASSII IODIDUM—POTASSIUM IODIDE
Derivation.—Potassium iodide may be prepared in the same manner as potassium bromide iodine, being used in place of bromine.
Properties.—It is a colorless, transparent, translucent, or opaque white, cubical crystals, or white granular powder, having a peculiar, faint, iodine-like odor and a pungent, saline, afterwards bitter, taste. Permanent in dry air and but slightly deliquescent in moist air. Soluble in 0.7 parts of water, and in about 12 parts of alcohol at 77° F., in 0.5 parts of boiling water, in 6 parts of boiling alcohol; also soluble in 2.5 parts of glycerine.
Actions.—Potassium iodide closely resembles iodine but is less powerful and devoid of local irritant action. Medical doses are antiseptic, desquamatic, deobstruent, expectorant, alterative and diuretic. It stimulates the lymphatic system. It is readily soluble, and is quickly absorbed in the tissues, where it undergoes decomposition; the iodine, when liberated, apparently combines with albuminoids and acts specially on the lymphatic glands and vessels, modifying nutrition, hastening metabolism and promoting absorption. It is doubtless in this way that it also unites with lead and mercury deposited in the tissues, renders them soluble, carries them into the circulation and causes their elimination.
It is quickly excreted by the mucus and skin surfaces, but chiefly by the kidneys.
Uses.—Potassium iodide is useful in promoting absorption of enlarged lymphatic glands, and its action should be assisted by the application of iodine or red iodide of mercury externally. Potassium iodide in small doses diminishes congestion and increases the fluidity and amount of secretions in acute laryngitis, acute and subacute bronchitis, and appears to possess an alterative action in improving the condition and nutrition of the bronchial mucous membranes. It is also of some value in asthma, pulmonary emphysema and chronic bronchitis, unassociated with copious secretion. Chronic pleuritis, pericarditis and ascites are treated with potassium iodide, which assists absorption and occasionally exerts a diuretic effect. Tardy resolution of pneumonia consolidation is hastened by potassium iodide. Endocarditis with cardiac hypertrophy is said to be benefited by potassium iodide and digitalis.
Champignon, or scirrhous cord in horses, is sometimes cured by the sorbefacient powers of potassium iodide in full doses. Potassium iodide is of value in goiter of dogs, calves and sheep when tincture of iodine is used externally. “Roaring” and “thick wind” may be cured by the administration of potassium iodide. It is the best medicine known for actinomycosis. Potassium iodide has a clinical reputation for its power to aid absorption and resolution in inflammation or effusions of the brain or spinal cord, in paralysis of the body or limbs and inflammation of the membranes covering the brain.
Doses.—Horses, 2 to 4 dr.; cattle, 3 to 6 dr.; sheep and pigs, 15 to 30 gr.; dogs, 1 to 10 gr.
It should be given to the larger animals in doses of three drachms daily, until iodism appears, which shows itself by loss of appetite, an irritable, catarrhal condition of the mucous membranes of the nostrils, eyes, throat and digestive organs, a vesicular skin eruption, abstinence from water, diminished secretions of urine, temperature elevated and emaciation.