Ephedrine is a member of the adrenergic bronchodilator class of drugs that serve to open up the bronchial tubes of the lungs. Since the 1920s, synthetic versions of this drug have been used as a bronchodilator and nasal decongestant, and for controlling urinary incontinence. Although ephedrine is too slow acting to treat acute allergic attacks, it replaces epinephrine in nonemergency treatment of allergic reactions.
Ephedrine is derived from any of several species of evergreen shrub belonging to the genusEphedra, but E. sinica is the primary botanical source for the alkaloid ephedrine. While some ephedra species have no alkaloid content, E. sinica typically has the highest concentration of ephedrine. The alkaloid content of E. sinica ranges from one to three percent; 40% to 90% of the alkaloids are ephedrine, with the remainder made up of pseudoephedrine, norephedrine and norpseudoephedrine.
E. sinica is native to northern China and inner Mongolia. In Chinese, it is called "ma huang." It has been called the world's oldest medicine, since it has been used to treat symptoms of colds and asthma in traditional Chinese medicine for over 5,000 years. Traditionally, the dried stems were crushed and administered in powder form or in a tea.