Botanical name: 

The leaves of Gaultheria procumbens, Linné (Nat. Ord. Ericaceae). Damp woods and sandy soils of eastern third of the United States.
Common Names: Wintergreen, Teaberry, Mountain Tea, Boxberry.

Principal Constituents.—An aromatic volatile oil (Oleum Gaultheriae); arbutin, ericolin and urson.
Preparations.—1. Oleum Gaultheriae, Oil of Wintergreen. True Oil of Wintergreen; composed of about 96 per cent of methyl salicylate. Dose, 5 to 15 drops.
2. Specific Medicine Gaultheria. Dose, 5 to 20 drops.
3. Spiritus Gaultheriae, Spirit of Gaultheria (Essence of Wintergreen—5 per cent of oil in alcohol). Chiefly a flavor essence.
Related Oil.—Methylis Salicylas, Methyl Salicylate or Artificial Oil of Wintergreen. This is prepared synthetically and sold under the name of Oil of Wintergreen. Its source must be stated on the label. It ranges from colorless to yellowish or reddish and has the odor and taste of wintergreen. Dose, 5 to 15 drops.
Specific Indications.—Irritation of the bladder and prostate gland; undue sexual excitement, and early stage of renal inflammation.

Action.—Oil of wintergreen has identically the same physiological action as salicylic acid except that in poisonous doses it is more certain to produce coma. The symptoms of toxic doses are drowsiness, cerebral congestion with throbbing of the carotids, delirium, contracted or dilated pupils, visual disturbances, tinnitus aurium, paresis, somnolence, and coma preceding death. Autopsy reveals congestion of the stomach, duodenum, and the kidneys.

Therapy.—External. Oil of wintergreen in full strength may be applied to carious teeth to relieve toothache. In full strength, or in suitable dilution with olive oil or cottonseed oil, it provides a good pain-relieving application for acute articular and chronic rheumatism and in gonorrheal arthritis. If used very strong the skin may subsequently exfoliate. Applied to denuded surfaces it is readily absorbed and may produce toxic effects.

Embrocations containing oil of wintergreen are valuable for local inflammatory swellings, neuralgic pain, pleurodynia, myalgia, itching, and swelling and stiffness of the joints. The following are a few of many such liniments: (1) Oil of Gaultheria, 3 fluidrachms; Oil of Olive, enough to make 6 fluidounces. Mix. (2) Oil of Gaultheria, 3 drachms; Salicylic Acid, 20 grains; Alcohol, 2 fluidounces; Oil of Olive, enough to make 6 fluidounces; Mix. Shake when used. Especially useful upon rheumatic joints. (3) Oil of Gaultheria, 3 fluidrachms; Chloroform Liniment and Soap Liniment, 2 fluidounces each. Mix. Shake when used. For painful surfaces. (4) Oil of Gaultheria, 2 fluidounces; Asepsin, 15 grains; Echafolta and Alcohol, 2 ½ fluidounces each. Mix. Valuable for application to cuts, bruises, and diluted with water as a mouth wash.

Internal. Specific Medicine Gaultheria, or an infusion (Leaves, 1 ounce to Water, 16 fluidounces), has a specific action upon the urino-genital tract, relieving irritation and subacute inflammation. This action is especially exerted upon the neck of the bladder and in the prostatic urethra. It does not greatly increase the secretion of urine, but renders its voiding easier by alleviating the sphincteric irritation. It is, therefore, a remedy for dysuria. In incipient renal inflammation it sometimes does good, and in acute tubal nephritis it is asserted to have given benefit even where blood and tube casts are passed. Considerable good has been accomplished with it when spermatorrhea and sexual excitement are caused by urethral irritability and prostatic fullness. The specific medicine may be administered in 5 to 15 drops doses in water 3 or 4 times a day. Some physicians have advised both gaultheria and its oil for the relief of hepatic congestion and in sluggish vascularity and engorgement of the intestinal glands, as well as to relieve hemorrhoids by overcoming congestion of the portal vessels.

Oil of gaultheria has aromatic and antiseptic properties. It consists most largely of methyl salicylate, over 90 parts at least, and is therefore analogous to salicylic acid and the salicylates in its effects. Large doses depress the heart just as the salicylates do; large doses also cause nausea and vomiting. Used within bounds, short of sufficient to induce gastric derangement, it is very useful where an anti-rheumatic is demanded and in cystic disorders with putrescent urine. Too long continued, however, it may induce renal irritation, and this must be carefully guarded against. Urine that was ammoniacal and putrescent a few hours after passage has been followed, after the administration of twenty drops of the oil, by an output that remained free from putrefaction for twelve days. One part of the oil in about two hundred of urine has preserved the latter from change for eighteen days. Hence the value of this oil in cystitis with putrescent urine. While few agents should be administered with digitalis, oil of wintergreen is a grateful adjuvant and does not impair the usefulness of the foxglove. If for any reason sodium salicylate disagrees with rheumatic patients, oil of wintergreen, which is less likely to contain deleterious by-products, may be given. It is useful in all types of acute rheumatism in which salicylic acid or the salicylates are effective. Those most benefited are the acute inflammatory rheumatism and so-called gonorrheal rheumatism, a specific gonorrheal arthritic infection. Small doses have relieved facial neuralgia and tic douloureux; and sometimes it exerts a soothing and antiseptic effect in acute gonorrhea. The oil may be administered in olive oil or in the form of the spirit (essence) mixed with sweetened water.

The essence is of service in dry, persistent bronchial cough, and the specific medicine in cough with considerable bronchial secretion. It is also useful in the colic of infants.

Gaultheria is an agent of special value as a flavoring agent and preservative for water-dispensed medicines in the summer season. For this purpose it should be widely used. The spirit (50 parts of oil of gaultheria to 950 parts of alcohol) is the preferred form for this purpose.

The Eclectic Materia Medica, Pharmacology and Therapeutics, 1922, was written by Harvey Wickes Felter, M.D.