Ephedrine hypotension, treatment

Chinese medical practitioners in the 15th century recommended ephedra as an antipyretic and antitussive agent. Modem physicians use intravenous ephedrine for the prophylaxis and treatment of hypotension caused by spinal anesthesia, particularly during cesarean section (see Chapter 29). 

Ephedrine, given im/iv/sc, is indicated for the treatment of acute hypotensive states, treatment of Adams-Stokes syndrome with complete heart block, stimulation of the central nervous system (CNS) to combat narcolepsy and depressive states, treatment of acute bronchospasm, treatment of enuresis, and treatment of myasthenia gravis. When given in nasal form, ephedrine is used in the treatment of nasal congestion, promotion of nasal or sinus drainage, or relief of eustachian tube congestion. 

The medicinal use of Ephedra sinica in China dates from 2800bc. Ma Eluang (the stem and branch) was used primarily in the treatment of common cold, asthma, hay fever, bronchitis, edema, arthritis, fever, hypotension, and urticaria. Ephedra has been used to treat bronchoconstriction for centuries, because of its activity at /li-adrenergic receptors. It contains pseudoephedrine, ephedrine, and other similar alkaloids. These are sympathomimetics that either directly or indirectly stimulate a- and jS-adrenergic receptors. It has become less extensively used with the advent of more selective agonists. 

Physicians routinely used intravenous ephedrine for the prophylaxis and treatment of hypotension caused by spinal anesthesia particularly during caesarean section (9). In the past, ephedrine was used to treat Stokes-Adams attacks (complete heart block), and was also recommended as a treatment for narcolepsy. Over the years, ephedrine has been replaced by other, more effective agents (10), and the advent of highly selective [3-agonists has mostly eliminated the need to use ephedrine in treating asthma. 

In the past, ephedrine was used to treat Stokes-Adams attacks with complete heart block and as a CNS stimulant in narcolepsy and depressive states. It has been replaced by alternate treatments in each of these disorders. In addition, its use as a bronchodilator in patients with asthma has become much less extensive with the development of p2-selective agonists. Ephedrine has been used to promote urinary continence, although its efficacy is not clear. Indeed, the drug may cause urinary retention, particularly in men with benign prostatic hyperplasia. Ephedrine also has been used to treat the hypotension that may occur with spinal anesthesia. 

Ephedrine, isolated from Ephedra sinica, is the major active constituent of this plant species. It is used in the treatment of asthma, nasal congestion, and as a prophylactic to avoid hypotension associated with spinal anesthesia for cesarean section [55]. Herbal products containing Ephedra are used as antiobesity agents and energy boosters despite reports on serious side-effects, such as hypertension, seizures, myocardial infarction [56]. The 15,2/ -(- -)-enantiomer of ephedrine is not present in the plant. 

---