Flupentixol, marketed as Fluanxol and Depixol by Lundbeck, is a thioxanthene antipsychotic developed in Denmark in the 1960s. It comes in two forms: oral tablets used for both schizophrenia and (at lower doses) depression and anxiety, and a long-acting depot injection (flupentixol decanoate) used for maintenance treatment of schizophrenia. Like its thioxanthene cousin zuclopenthixol, flupentixol has never been approved in the United States but has decades of use in the UK, continental Europe, Canada, Australia, South Africa, and elsewhere.
Flupentixol is a thioxanthene antipsychotic used internationally for schizophrenia, with oral and depot forms and an unusual additional low-dose indication for depression and anxiety, never approved in the United States.
How it works
Flupentixol blocks dopamine D1 and D2 receptors and has affinity for serotonin 5-HT2 receptors. Its receptor profile is slightly more activating than zuclopenthixol's — many patients describe it as less sedating, sometimes mildly energising at low doses. This is part of why low-dose flupentixol has been used as an antidepressant in some countries.
Oral flupentixol: dosing
Per international product information (e.g., the UK eMC labelling), oral flupentixol for schizophrenia is typically dosed at 3 to 9 mg per day in divided doses, occasionally higher in severe cases. For depression and anxiety, much lower doses (0.5 to 2 mg per day) are used, divided morning and noon to avoid disturbing sleep. The maximum dose for the depression/anxiety indication is generally 3 mg per day; higher doses are reserved for psychotic conditions.
Flupentixol decanoate (depot)
The depot form is given by deep intramuscular injection every 2 to 4 weeks. Typical doses are 20 to 100 mg every 2 to 4 weeks, with adjustments based on response and tolerability. Some patients are stable on lower or higher doses; older adults usually need the lower end. The slow release of decanoate ester from the oily injection produces relatively steady plasma levels over weeks.
The unusual depression indication
The use of low-dose flupentixol as an antidepressant is notable because it sits outside the modern standard of care for depression in most countries. The indication dates from older European clinical trials suggesting low-dose antipsychotic effect on mood and anxiety. Modern psychiatric guidance generally recommends SSRIs, SNRIs, or other established antidepressants first, with antipsychotics added in specific situations. Flupentixol's depression indication remains in some product information but is not commonly used in 2026 except in selected cases. Patients prescribed low-dose flupentixol for depression should ask the prescriber about the rationale relative to standard antidepressants.
Side effects
Movement effects
Acute dystonia, parkinsonism, and akathisia are common, particularly at higher antipsychotic doses. Anticholinergic medications such as procyclidine or benztropine are sometimes co-prescribed. Tardive dyskinesia risk accumulates with long-term use.
Sedation
Generally mild to moderate. Less than zuclopenthixol or chlorpromazine. At low doses some patients describe a mild stimulating effect.
Anticholinergic and orthostatic
Modest. Dry mouth, constipation, blurred vision possible. Orthostatic hypotension can occur.
Weight gain and metabolic effects
Modest. Less than olanzapine or clozapine. Periodic monitoring of weight, glucose, and lipids is reasonable.
Hyperprolactinemia
Substantial at higher doses, less prominent at the low doses used for depression.
Cardiovascular
QT prolongation possible. Orthostatic hypotension may occur during initiation.
Injection site reactions (depot)
Pain, redness, induration. Deep gluteal injection technique and site rotation help.
Severe muscle stiffness with high fever and confusion, severe sudden involuntary movements, fainting, or signs of an allergic reaction.
Boxed warnings (international)
International labels include the standard antipsychotic warning about increased mortality in elderly patients with dementia-related psychosis. EPS, NMS, QT prolongation, and tardive dyskinesia warnings are also standard.
Drug interactions
Additive sedation with CNS depressants. Additive QT effects with other QT-prolonging drugs. Lowered seizure threshold. Anticholinergic effects compound those of other anticholinergics. Always disclose all medications and supplements.
Where flupentixol fits today
In countries where it is available, flupentixol is used:
- As oral or depot maintenance for schizophrenia, particularly when sedation needs to be avoided
- As a generic option in cost-constrained settings
- In patients with predominantly negative symptoms — some clinicians find the activating profile useful, although the evidence base is limited
- Occasionally for low-dose use in depression or anxiety, although standard antidepressants are usually preferred
In the US, equivalent depot options are fluphenazine decanoate or haloperidol decanoate among typicals, and second-generation depots such as paliperidone palmitate or aripiprazole monohydrate.
For patients moving between countries
Patients stable on flupentixol who move to the US will need to transition to an antipsychotic available there. Patients moving to the UK, Canada, or Europe will find flupentixol available as an additional option. Cross-titration of depots is best planned with an experienced prescriber.
Practical questions to ask your prescriber
- Why flupentixol — what alternatives have been considered?
- Should I be on oral, depot, or both?
- If using low-dose flupentixol for depression, why not a standard antidepressant?
- What is the AIMS exam schedule for monitoring tardive dyskinesia?
- What baseline ECG, weight, and labs do I need?
The big picture
Flupentixol is a flexible, well-established antipsychotic outside the US. The depot form has a clear maintenance role; the oral form is workable for daily use; the low-dose depression indication is unusual and worth questioning relative to modern standards. As with all antipsychotics, the conversation about whether it fits is best had with a prescriber who knows your full picture and the local context.
This article is for educational purposes only and is not medical advice. Information is summarised from publicly available FDA labelling, regulatory sources, and peer-reviewed literature. Always consult your prescribing clinician before starting, stopping, or changing any medication.