ephedrine (Ĭfĕd´rĬn, ĕf´Ĭdrēn´), drug derived from plants of the genus Ephedra (see Pinophyta), most commonly used to prevent mild or moderate attacks of bronchial asthma. Unlike epinephrine, to which it is chemically similar, ephedrine is slow to take effect and of mild potency and long duration. A bronchodilator and decongestant, ephedrine is used to relieve nasal congestion originating from allergic conditions, e.g., hay fever, or from bacterial or viral infection of the upper respiratory tract. It may be used as well to raise blood pressure. Ephedrine also is used in the production of methamphetamine (see amphetamine).
Ephedrine is the active constituent of ma huang, an herbal preparation used medically in China for thousands of years. Also commonly known as ephedra, it is derived from several Asian species of Ephedra. Preparations of these species were formerly used in "natural" dieting aids and bodybuilding supplements and also were marketed as "herbal ecstasy." Ephedra and ma huang may cause such side effects as insomnia, restlessness, euphoria, palpitations, and high blood pressure; there have been reports of a number of deaths associated with their use as recreational drugs and dietary supplements. In 2004 the Food and Drug Administration banned sales of dietary supplements containing ephedra because of illnesses and deaths associated with the drug.