What is Esketamine?

You may have seen that an antidepressant called “Esketamine” has been approved for use in the UK. Sounds a bit like ketamine you’re thinking, and you’d be right. It is a purified form of the more well-known drug, commonly thought of as a horse tranquiliser and often used as a drug of abuse. Many drug molecules come in two forms, what you might refer to as a left-handed and a right-handed form. When they are manufactured, both the left (known as the S) and the right (labelled R) form are produced, usually in equal quantities. Often one form, R or S is more active than the other, as is the case with the painkiller ibuprofen. Sometimes, one form is active and the other form causes side effects. This is the case with thalidomide, although the forms are interconverted in the body so it is impossible to make a safe form of that particular drug for women who are or might get pregnant. Standard manufacture of ketamine produces the R and the S form, (R,S)-2-(2-chlorophenyl)-2-(methylamino)cyclohexanone. The R form, interacts with additional receptors in the body that are not the chosen target of the drug and so lead to side effects. Hence, the need to produce ketamine as the S form only for use in treating depression. The drug S-ketamine, thus becomes esketamine. The S form is twice as potent as the mixture of R and S. The R form is nominally arketamine, clever naming. Esketamine is marketed as Ketanest and Spravato, commonly used as a general anesthetic (intr...
Source: David Bradley Sciencebase - Songs, Snaps, Science - Category: Science Authors: Tags: Sciencebase Source Type: blogs