Thioridazine

Thioridazine

Clinical data
AHFS/Drugs.com	Consumer Drug Information
MedlinePlus	a682119
License data	US DailyMed: 9c4bedb4-2d59-4fcd-aad7-fce988cd96d8 US FDA: Thioridazine
Pregnancy category	AU: C US: C (Risk not ruled out)
Routes of administration	Oral
ATC code	N05AC02 (WHO)
Legal status
Legal status	Withdrawn by the manufacturer worldwide
Pharmacokinetic data
Bioavailability	incomplete
Metabolism	hepatic (at least partly mediated by CYP2D6)
Biological half-life	21-24 hours
Excretion	faeces
Identifiers
IUPAC name 10-{2-[(RS)-1-Methylpiperidin-2-yl]ethyl}- 2-methylsulfanylphenothiazine
CAS Number	50-52-2 Y
PubChem CID	5452
IUPHAR/BPS	100
DrugBank	DB00679 Y
ChemSpider	5253 Y
UNII	N3D6TG58NI
KEGG	D00373 Y
ChEBI	CHEBI:9566 Y
ChEMBL	CHEMBL479 Y
ECHA InfoCard	100.000.041
Chemical and physical data
Formula	C21H26N2S2
Molar mass	370.577
3D model (Jmol)	Interactive image
SMILES S(c2cc1N(c3c(Sc1cc2)cccc3)CCC4N(C)CCCC4)C
InChI InChI=1S/C21H26N2S2/c1-22-13-6-5-7-16(22)12-14-23-18-8-3-4-9-20(18)25-21-11-10-17(24-2)15-19(21)23/h3-4,8-11,15-16H,5-7,12-14H2,1-2H3 Y Key:KLBQZWRITKRQQV-UHFFFAOYSA-N Y

Thioridazine (Mellaril or Melleril) is a piperidine typical antipsychotic drug belonging to the phenothiazine drug group and was previously widely used in the treatment of schizophrenia and psychosis; the branded product was withdrawn worldwide in 2005 because it caused severe cardiac arrhythmias, however, generic versions are available in the US.

Thioridazine was voluntarily discontinued by its manufacturer, Novartis, worldwide because it caused severe cardiac arrhythmias.

Its primary use in medicine was the treatment of schizophrenia. It was also tried with some success as a treatment for various psychiatric symptoms seen in people with dementia, but chronic use of thioridazine and other anti-psychotics in people with dementia is not recommended.

For further information see: Phenothiazine

Thioridazine prolongs the QTc interval in a dose-dependent manner. It produces significantly less extrapyramidal side effects than most first-generation antipsychotics. Its use, along with the use of other typical antipsychotics, has been associated with degenerative retinopathies. It has a higher propensity for causing anticholinergic side effects coupled with a lower propensity for causing extrapyramidal side effects and sedation than chlorpromazine, but also has a higher incidence of hypotension and cardiotoxicity. It is also known to possess a relatively high liability for causing orthostatic hypotension compared to other antipsychotics. Similarly to other first-generation antipsychotics it has a relatively high liability for causing prolactin elevation. It is moderate risk for causing weight gain. As with all antipsychotics thioridazine has been linked to cases of tardive dyskinesia (an often permanent neurological disorder characterised by slow, repetitive, purposeless and involuntary movements, most often of the facial muscles, that is usually brought on by years of continued treatment with antipsychotics, especially the first-generation (or typical) antipsychotics such as thioridazine) and neuroleptic malignant syndrome (a potentially fatal complication of antipsychotic treatment). Blood dyscrasias such as agranulocytosis, leukopenia and neutropenia are possible with thioridazine treatment.