A secondary alcohol obtained from the oil of Mentha piperita, Linné, or from other oils of mints. It should be kept in well-stoppered bottles, and in a cool place.
Description.—Colorless needle or prismatic crystals with a strong odor and taste characteristic of peppermint, very soluble in alcohol, ether, and chloroform, and slightly soluble in water. It gives a feeling of warmth when tasted, followed by a sensation of cold when air is inhaled or water is drunk. Dose, 1/8 to 2 grains.
Specific Indications.—Pruritus; nausea and vomiting.
Action and Therapy.—External. Menthol is a local antiseptic, anaesthetic and antipruritic. It is used with great success in various disorders attended with itching and pain. It may be used alone or rubbed up with camphor, chloral hydrate, or phenol in combinations desired, and painted upon painful surfaces or employed to obtund the pain in a carious tooth. In alcoholic or oil solution it is an unexcelled application for the itching of hives, pruritus vulvae et ani, eczema, ringworm, or herpes zoster. For pain and cellular inflammations it is very effectual in burns and scalds, insect bites and stings, earache, neuralgia, boils, carbuncles, and the surface pains of sciatica. The pain of local and superficial neuralgias and of arthritis, simple, rheumatic, or gonorrheal, may be relieved by painting upon the affected surface a combination of hydrated chloral, thymol, and menthol. A 20 per cent mentholated petrolatum may be used as a stimulating agent when there is a lack of cerumen in the auditory canal, and for boils in that passage a 20 per cent oil solution is very comforting. A 10 to 20 per cent solution in liquid petrolatum or olive oil gives relief in coryza and hay fever, or may be sprayed into the larynx for the relief of the distressing pain of laryngeal tuberculosis. An albolene spray of menthol is largely employed in inflamed and irritable conditions of the nose and throat—ozaena, catarrhal sore throat, asthma, chronic bronchitis, and whooping cough. The vapor is useful to allay harassing and irritable bronchial cough.
Internal. Minute doses of menthol relieve nausea and vomiting, as of pregnancy and seasickness. It is sometimes of value in hiccough. It should not be used in large doses internally because of the profound nervous disturbances it may occasion.