Latin, Iodum (Gen., Iodi)

Eng., Iodine. Synonym, Resub-limed Iodine. A solid element, at one time largely obtained from the ashes of seaweed, known as Kelp, now chiefly from the niter beds of South America.

Form

Heavy, bluish-black plates of a metallic luster.

Odor And Taste

A distinctive, penetrating odor; a sharp, acrid taste.

Solubility

In about 2950 parts of water; in 12.5 parts of alcohol. More soluble in the presence of Potassium Iodide.

Incompatibles

Alkaloids, ammonia, mineral acids, tannic acid, oil of turpentine, starch, vegetable colors, etc.

Average Dose

1/12 grain (0.005 Gm.).

Official Preparations.

Liquor Iodi Compositus

Eng., Compound Solution of Iodine. Synonym, Lugol's Solution. Iodine, 5 Gm.; Potassium Iodide, 10 Gm.; Water, to make 100 mils.

Average Dose

3 minims (0.2 mil).

Tinctura Iodi

Eng., Tincture of Iodine. Synonym, Compound Tincture of Iodine. Iodine, 70 Gm.; Potassium Iodide, 50 Gm.; Water, 50 mils; Alcohol, to make 1000 mils.

Average Dose

1 l/2 minims (0.1 mil).

Unguentum Iodi

Eng., Iodine Ointment. Iodine, 4 Gm.; Potassium Iodide, 4 Gm.; Glycerin, 12 Gm.; Benzoinated Lard, 80 Gm.

Therapeutic Action

Germicide, irritant, alterative, resolvent.

Uses

Sometimes used in the treatment of goiter, typhoid fever, diarrhea, vomiting, etc. Locally, it is used for disinfecting the skin for surgical work and for disinfecting fresh wounds, abscesses, etc.; also used as an application for toothache, tonsillitis, ulcers, adenitis, erysipelas, and superficial infections generally. Used as a counterirritant in pleurisy and many other conditions. Sometimes used by inhalation for bronchitis, etc.

Toxicology

Chronic iodine poisoning is discussed under "Iodides." Acute iodine poisoning is usually evidenced by the characteristic discoloration of the mucous membrane of the mouth and throat. The treatment consists in administering starch or, if that is inaccessible, a dilute solution of ammonia. Demulcent drinks should be given freely. If the quantity of the drug taken is large, emesis should be induced.

Administration

The Tincture is the preparation most commonly used. It is usually prescribed alone. The present official tincture, which contains Potassium Iodide, is freely miscible with either water or alcohol. Before the U. S. P., viii, the tincture of iodine did not contain potassium iodide; so it was insoluble in water to any appreciable extent. This caused many to order a tincture containing the iodide which was unofficial; it is the same as the present tincture of iodine, but was then called the compound tincture. It will be seen, therefore, that there is now no"compound tincture,"known as such. Somewhat similar misunderstanding sometimes occurs relative to the old"resublimed iodine."All "iodine"is now resublimed. Therefore to prescribe the"compound" tincture of iodine or"resublimed"iodine is unnecessary, and shows a lack of knowledge of present conditions.

The pure tincture of iodine is rather strong for common use, and many institutions dilute it one-half as a routine measure. If the undiluted tincture is applied to the skin several days in succession it will often irritate, or even blister.

Much of the blistering resulting from the local application of iodine is due to the presence of some dressing or application containing a mercuric salt, the red mercuric iodide (a powerful irritant) being formed.

When a bottle containing the tincture of iodine is left open the alcohol evaporates more rapidly than the iodine; so there is a concentration of the solution, and this may take place to where one application will blister.

When the tincture is carried for some time in a cork-stoppered bottle, sufficient of the cork may be acted upon and dissolved to interfere with obtaining a clear solution when the preparation is added to water. Some frequently used prescriptions are shown in the following:

As a local application in the treatment of tonsillitis, inflamed glands, abscess, furuncle, insect-bite, inflamed joints, etc.:

Sig

Apply once daily as directed. (Poison-label.)

Or, better still is the following, known by the dentists as"Iodine and aconite":

Sig

Apply twice a day as directed. (Poison-label.)

It may usually be applied to the skin several days before too much local irritation develops.

This is also extensively used in the treatment of toothache.

As a local application for tonsillitis, etc.; also for clavus:

M.

Sig

Apply as directed.

As an application to mucous membrane:

M.

Sig

Apply as directed.

Iodine is sometimes used internally in the treatment of goiter:

M.

Sig

Teaspoonful in water after meals.

As a vaginal douche in vaginitis, endometritis, ovaritis, salpingitis, etc.:

Sig

Use teaspoonful to gallon of hot water every second night.

1 Ruhrah: Diseases of Children.

This makes about as strong a solution as can well be tolerated by the patient and often proves too strong. If used oftener than once a day it will frequently cause too much irritation. It is usually employed in connection with the daily or twice daily douches of hot saline.

Official Iodides.

Incompatibles

Mineral acids and salts, alkaloids, bismuth subnitrate, soluble lead salts, mercurous salts, glycyrrhiza, potassium chlorate, spirit of nitrous ether, silver nitrate, starch.