Ephedrine is a medication used to prevent low blood pressure during spinal anesthesia. It has also been used for asthma,narcolepsy, and obesity but is not the preferred treatment. It can be taken by mouth or by injection into a muscle, vein, or just under the skin. Onset with intravenous use is fast, while injection into a muscle can take 20 minutes, and by mouth can take an hour for effect. When given by injection it lasts about an hour and when taken by mouth it can last up to four hours.
Common side effects include, trouble sleeping, anxiety, headache, hallucinations, high blood pressure, fast heart rate, loss of appetite, and inability to urinate. Serious side effects include stroke, heart attack, and abuse. While likely safe in pregnancy its use in this population is poorly studied. Use during breastfeeding is not recommended. Ephedrine works by turning on α and βadrenergic receptors.
Ephedrine was first isolated in 1885. It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system. It is available as a generic medication. The wholesale cost is about 0.69 to 1.35 USD per dose. In the United States it is not very expensive. It can normally be found in plants of the Ephedra type. Dietary supplements that contain ephedrine are illegal in the United States. An exception is when used in traditional Chinese medicine.