1. n. Bioch. A crystalline alkaloid found naturally in some ephedras, used in drugs to treat asthma and head colds.
From modern Latin ephedra, «ephedra», and the suffix -ine.
Ephedrine is a naturally-occurring alkaloid produced by several species of the genus Ephedra (Ephedraceae). It is commercialized in the form of a salt for relief of hay fever, asthma, and nasal congestion.
Originally, ephedrine was obtained from Chinese ephedras, particularly Ephedra sinica, but in the West it has been commercially synthesized since the 1920s.
Effects on the human body
Ephedrine causes constriction of the blood vessels and widening of the bronchial passages. Its action is slow, but its effect lasts for several hours.
Ephedrine is a natural bronchodilator (a drug that relaxes bronchial muscle, resulting in expansion of the bronchial air passages) and nasal decongestant (a medicinal agent that relieves nasal congestion). In China, several native species of ephedras are being used for more than 5,000 years now to relieve asthma and treat hay fever (allergy to some kinds of pollen that appear in the springtime).
Commercial synthetic ephedrine is sold in the form of a salt to relieve asthma, hay fever, and nasal congestion. It is also used to control urinary incontinence.
Its activity is slower and its effect is lengthier than that of epinephrine. Hence ephedrine is unsuited for arresting acute allergic attacks. This limits its use to the nonemergency treatment of allergic reactions.
Because of its stimulant effects, ephedrine must sometimes be used in combination with sedatives.
Way of administration
Ephedrine is effective when administered orally.