Thioxanthene
# Thioxanthene

Thioxanthene is a chemical compound in which the oxygen atom in xanthene is replaced with a sulfur atom. It is also related to phenothiazine. Several of its derivatives are used as typical antipsychotics in the treatment of schizophrenia and other psychoses.

## Derivatives

The derivatives of thioxanthene used clinically as antipsychotics include:

* Chlorprothixene (Cloxan, Taractan, Truxal)
* Clopenthixol (Sordinol)
* Flupenthixol (Depixol, Fluanxol)
* Thiothixene (Navane)
* Zuclopenthixol (Cisordinol, Clopixol, Acuphase)

The therapeutic efficacy of these drugs is related to their ability to antagonize the $D_2$ receptors in the brain, though they have actions at other sites such as serotonin, adrenaline, and histamine receptors as well which mostly contribute to side effects.

The thioxanthenes, as a class, are closely related chemically to the phenothiazines. The major structural difference is that the nitrogen at position 10 in the phenothiazines is replaced by a carbon atom with a double bond to the side chain. This difference is noted in the illustration of flupenthixol, which shows a double-bonded carbon in the number 10 position (opposite the sulfur molecule in the central chain).

