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
D2 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). == References ==