Ephedrine

-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.

Side effects

-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.

Sources of Ephedrine

Agricultural                                                                                                     

Ephedrine is obtained from the plant Ephedra sinica and other members of the Ephedra genus. Raw materials for the manufacture of ephedrine and traditional Chinese medicines are produced in China on a large scale. As of 2007, companies produced for export US$13 million worth of ephedrine from 30,000 tons of ephedra annually, 10 times the amount used in traditional Chinese medicine.

Synthetic

Most of the l-ephedrine produced today for official medical use is made synthetically as the extraction and isolation process from E. sinica is tedious and no longer cost effective.

Biosyntheti

Ephedrine was long thought to come from modifying the amino acid L-phenylalanine.L-Phenylalanine would be decarboxylated and subsequently attacked with ω-aminoacetophenone. Methylation of this product would then produce ephedrine. This pathway has since been disproven.A new pathway proposed suggests that phenylalanine first forms cinnamoyl-CoA via the enzymes phenylalanine ammonia-lyase and acyl CoA ligase. The cinnamoyl-CoA is then reacted with a hydratase to attach the alcohol functional group. The product is then reacted with a retro-aldolase, forming benzaldehyde. Benzaldehyde reacts with pyruvic acid to attach a 2 carbon unit. This product then undergoes transamination and methylation to form ephedrine and its stereoisomer, pseudoephedrine.