Chlorprothixene (Taractan, Truxal): Why This Thioxanthene Left U.S. Pharmacies and What Telehealth Can Still Do

Last updated: August 24, 2026

Chlorprothixene is a first-generation thioxanthene antipsychotic. U.S. clinicians once sold it as Taractan (Roche). Other names you may see on old bottles or overseas records include Truxal, Tarasan, and Clothixen. DrugBank classifies it as approved, experimental, investigational, and withdrawn. NCATS lists the hydrochloride as U.S. previously marketed, first approved in 1962. It is not a current U.S. retail option.

If you found “chlorprothixene,” “Taractan,” or “Truxal” on a chart from decades ago, or after a move from Europe, a licensed clinician can still review symptoms and discuss medicines U.S. pharmacies actually stock. Coverage varies by plan. Verify benefits before you book. If you are in crisis, call or text 988.

See conditions Klarity treats or start with online anxiety treatment if worry, restlessness, or tension is the main problem you want to discuss.

TL;DR

• Chlorprothixene is a typical thioxanthene antipsychotic (DrugBank DB01239). Formula C18H18ClNS. Average molecular weight 315.86. ATC N05AF03.
• It blocks 5-HT2, D1, D2, D3, histamine H1, muscarinic, and alpha-1 adrenergic receptors. DrugBank lists antipsychotic potency at about half to two-thirds of chlorpromazine, with antiemetic effects and a side-effect profile similar to chlorpromazine (allergic reactions and liver injury reported less often in that write-up).
• Historic U.S. brand: Taractan by Roche, first approved 1962 (NCATS 268KCR965N). Salt UNII 268KCR965N. CAS 6469-93-8. RxNorm RXCUI 91133.
• NCATS sample oral use guide: usual adult dose 15-100 mg for milder symptoms or 100-400 mg for severe symptoms. After a 15 mg single oral dose in fasting adults, one experiment reported Cmax 11 ng/mL, AUC 187 ng·h/mL, and half-life 8.4 hours (PubMed 1140253, as cited on the NCATS card). DrugBank lists half-life as 8 to 12 hours.
• PubChem’s thiothixene record notes chlorprothixene is no longer commercially available in the U.S. Do not buy research-grade powder or unlabeled overseas tablets and swallow them.
• Medicare behavioral telehealth in the home remains available on a permanent basis. Several other Medicare telehealth flexibilities run through December 31, 2027 (HHS page last updated February 5, 2026). Klarity’s 2,000+ licensed providers can evaluate current symptoms. They cannot restart Taractan.

On this page

• What is chlorprothixene?
• Taractan, Truxal, and the 1962 U.S. approval
• How this thioxanthene worked
• Historic doses and pharmacokinetics
• Safety, overdose, and what not to do
• What telehealth can still do
• How Klarity fits
• FAQ

What is chlorprothixene?

DrugBank DB01239 calls chlorprothixene a typical antipsychotic of the thioxanthene (tricyclic) class. Synonyms include Chlorprothixen, Chlorprotixen, Chlorprotixene, and Alpha-Chlorprothixene. The hydrochloride salt is the form NCATS catalogs as previously marketed in the United States.

Indication language on DrugBank is treatment of psychotic disorders (for example schizophrenia) and of acute mania that occurs as part of bipolar disorder. That is historic pharmacology language, not a current U.S. label you can fill at a chain pharmacy.

Thioxanthenes sit next to phenothiazines on older psychopharmacology charts. Klarity already has live explainers for related molecules such as thiothixene (Navane), flupentixol (Fluanxol/Depixol), and zuclopenthixol (Clopixol). Chlorprothixene is the older, more sedating cousin that left U.S. shelves.

Taractan, Truxal, and the 1962 U.S. approval

NCATS lists chlorprothixene hydrochloride as U.S. previously marketed, first approved in 1962, source Taractan by Roche. Originator on that card is Lundbeck. Brands named in the NCATS description include Taractan, Tarasan, and Truxal. DrugBank’s international brand table adds Clothixen (Yoshitomi), Cloxan (Orion), and Taractan (Roche).

Identifiers that show up when a records team traces an old order: UNII 268KCR965N, CAS 6469-93-8 (salt) and 113-59-7 family listings on related records, InChIKey YWKRLOSRDGPEJR-KIUKIJHYSA-N, ECHA 229-289-3, EPA CompTox DTXSID701017267, PubChem CID 667467 for the parent, ATC N05AF03.

Treat every milligram figure below as historic. They are not a current prescription.

How this thioxanthene worked

DrugBank: chlorprothixene blocks postsynaptic mesolimbic D1 and D2 receptors, depresses hypothalamic and hypophyseal hormone release, and is believed to depress the reticular activating system, which can affect basal metabolism, body temperature, wakefulness, vasomotor tone, and emesis. Listed antagonist targets include D2, D1, D3, 5-HT2A, histamine H1, and muscarinic M1–M5.

NCATS potency notes (from curator-compiled sources on that card): D2 Ki 3.4 nM, H1 Ki 3.75 nM, D1 Ki 18.0 nM. Those are binding numbers, not a home-dosing guide.

DrugBank pharmacodynamics: low antipsychotic potency (about half to two-thirds of chlorpromazine); antiemetic effects demonstrated; antidepressant and analgesic effects not thoroughly demonstrated; side-effect profile similar to chlorpromazine, with allergic reactions and liver damage described as less frequent in that comparison.

Food note from DrugBank: avoid alcohol; take with food because food reduces irritation.

Historic doses and pharmacokinetics

NCATS “sample in vivo use guide”: usual adult oral dose 15-100 mg for mild to moderate symptoms or 100-400 mg for severe symptoms. That is an archived field, not an FDA Medication Guide.

A single 15 mg oral dose in fasting healthy adults, as summarized on NCATS from PubMed 1140253: Cmax 11 ng/mL, AUC 187 ng × h/mL, half-life 8.4 hours. DrugBank lists half-life as 8 to 12 hours, absorption as incomplete bioavailability, and metabolism as hepatic. NCATS also flags CYP2D6 substrate activity.

Highest studied oral dose listed on the NCATS card is 1800 mg once daily in an unhealthy adult group (PubMed 1314010). Seven patients discontinued or needed a dose cut for polyneuropathy. That is a toxicity signal, not a target dose.

Safety, overdose, and what not to do

DrugBank overdose symptoms include severe breathing difficulty, severe dizziness, severe drowsiness, severe muscle trembling, jerking, stiffness, or uncontrolled movements, small pupils, unusual excitement, and unusual tiredness or weakness.

Class first-generation antipsychotic risks still matter on old records: extrapyramidal symptoms, tardive dyskinesia, neuroleptic malignant syndrome, sedation, orthostatic hypotension, anticholinergic effects, and the boxed-class warning that older adults with dementia-related psychosis who take antipsychotics have a higher chance of death. Chlorprothixene is not a current U.S. product, so there is no live DailyMed boxed-warning page to quote line by line. Clinicians still treat those class risks as real when they review history.

Do not import unlabeled Truxal or Taractan tablets. Do not swallow research-catalog chlorprothixene. If someone is rigid, febrile, collapsing, or cannot stay safe, call 911. For a mental health crisis, call or text 988.

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What telehealth can still do

Telehealth.HHS.gov (last updated February 5, 2026) states that Medicare patients can permanently receive behavioral and mental telehealth in the home, with no geographic originating-site restriction, and that audio-only remains permanently allowed for those behavioral services. An in-person visit within six months of an initial Medicare behavioral telehealth service, and annually after that, is not required through December 31, 2027.

A Klarity visit can cover current psychosis, mania, anxiety, or depression questions and compare FDA-available options. It cannot restart Taractan. New or worsening psychosis with danger to self or others, suspected NMS, or inability to swallow still belongs in an emergency department.

How Klarity fits

Klarity connects adults with 2,000+ licensed U.S. providers. You can start on the condition pages, then book if a clinician agrees a video visit is appropriate. We do not promise that any plan will cover a specific medicine or visit type. Coverage varies. Verify benefits before you book.

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FAQ

Is Taractan still available in the United States?

No current U.S. commercial product is on typical retail shelves. NCATS status is U.S. previously marketed (1962, Roche). PubChem’s thiothixene monograph states chlorprothixene is no longer commercially available in the U.S.

Is chlorprothixene the same as thiothixene (Navane)?

No. Both are thioxanthenes. Thiothixene still has a generic capsule story in the U.S. Chlorprothixene (Taractan) does not.

What was a typical historic dose?

NCATS sample guide: 15-100 mg orally for milder symptoms, 100-400 mg for severe symptoms. That is historic, not a current order.

Can a telehealth clinician prescribe chlorprothixene?

Not as a standard U.S. retail fill. A licensed clinician can still evaluate symptoms and discuss available alternatives.

Does insurance cover a visit to talk about an old Taractan record?

Coverage varies by plan. Verify benefits before you book. Klarity cannot guarantee payment.

Disclaimer

This article is education, not medical advice, diagnosis, or a promise of treatment or insurance payment. Medication decisions belong to you and a licensed clinician. If you may harm yourself or someone else, call 911 or 988.

Sources: DrugBank DB01239; NCATS 268KCR965N; PubChem CID 667467; HHS telehealth policy updates.