Compound

Thioproperazine

Also called Thioperazine, Vontil, Tioproperazina

Original Wikipedia articleen.wikipedia.org/wiki/Thioproperazine revision used (24 October 2026)

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Overview

Thioproperazine, sold under the brand name Majeptil, is a typical antipsychotic of the phenothiazine group which is used as a tranquilizer, antiemetic, sedative, and in the treatment of schizophrenia and manic phase of bipolar disorder. Majeptil is available in 10 mg tablets.[1–5] WP

Risks and side effects

Side effects

Common[6] WP

Extrapyramidal symptoms[6] WP
Amenorrhea[6] WP
Decreased sexual interest and/or function[6] WP
Swelling of breasts and milk production in males and females[6] WP
Difficulty sleeping[6] WP
Constipation[6] WP
Reduced amount of urine[6] WP
Dizziness[6] WP
Drowsiness[6] WP
Dry mouth[6] WP
Nausea[6] WP
Headache[6] WP
Weight changes[6] WP

Rare but potentially serious adverse effects WP

Agranulocytosis WP
Neuroleptic Malignant Syndrome (NMS) WP
Sudden cardiac death WP
Torsades de pointes WP

Elderly individuals with dementia-related psychosis treated with antipsychotic medication are at an increased risk of death compared to individuals not receiving antipsychotics. WP

Interactions

Drug interactions

Medications for allergies (e.g., Benadryl diphenhydramine), certain medications for sleep (e.g., lorazepam, zopiclone), certain medications for pain (e.g., fentanyl), and Antiparkinson medications can increase the sedative effect of thioproperazine and can be potentially dangerous when used together. WP

Chemistry

Formula: C22H30N4O2S2 PC
CAS number: 316-81-4 PC
Molar mass (g/mol): 446.6 PC
IUPAC name (computed by PubChem): N,N-dimethyl-10-[3-(4-methylpiperazin-1-yl)propyl]phenothiazine-2-sulfonamide PC
SMILES: CN1CCN(CC1)CCCN2C3=CC=CC=C3SC4=C2C=C(C=C4)S(=O)(=O)N(C)C PC
InChIKey: VZYCZNZBPPHOFY-UHFFFAOYSA-N PC
PubChem CID: 9429

Harm reduction information

No harm reduction data is on file for this compound yet. That means no dose, timing or combination data from PsychonautWiki or TripSit. Please don't guess a dose from similar compounds. If you have taken it and feel unwell, contact emergency services or a poison control center.

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Pop culture

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Sources

Other Index Nominum 2000: International Drug Directory. 2000
Other Morton IK, Hall JM. Concise Dictionary of Pharmacological Agents: Properties and Synonyms. 6 December 2012
Other Phenothiazines (Systemic)
Other Thioproperazine - Oral
Harm reduction site Thioproperazine
Other Schizophrenia Society of Ontario - Majeptil (thioproperazine)

Text and values on this page are quoted from Wikipedia (CC BY-SA 4.0), PubChem (public domain). Each value links to the exact revision it came from.