Trifluoperazine (Stelazine)

What it treats

Trifluoperazine is FDA-approved for schizophrenia and for short-term treatment of generalized non-psychotic anxiety. The anxiety indication is rarely used today, benzodiazepines, SSRIs, buspirone, and other options are almost always preferred. The main modern use is schizophrenia, especially where cost is a factor or a person has responded well to it in the past.

How it works

Trifluoperazine is a phenothiazine first-generation antipsychotic that blocks dopamine at the D2 receptor. That quiets the overactive dopamine signaling thought to drive hallucinations, delusions, and disorganized thinking. It has minimal action at histamine, muscarinic, or alpha-adrenergic receptors, which is what makes it high-potency, small doses do a lot of D2 work, and side effects like sedation, dry mouth, and blood pressure drop are less prominent.

Receptor mechanism (detail)

Trifluoperazine is a high-potency D2 antagonist. Its receptor selectivity is similar to fluphenazine and haloperidol, favoring D2 over other receptors. The trade-off is a higher rate of extrapyramidal side effects, parkinsonism, akathisia, and acute dystonia, and higher long-term risk of tardive dyskinesia compared with atypical antipsychotics. It also raises prolactin.

Potency and typical dosing pattern

Ranges are typical framework only, not a prescription for any individual. Trifluoperazine is high-potency.

A common starting range for schizophrenia is 2 to 5 mg twice daily. The usual range extends up to about 40 mg per day divided in two or three doses. For short-term anxiety (rarely used today), 1 to 2 mg twice daily is typical. The prescriber sets and adjusts the dose based on response and side effects.

Safety monitoring

• Involuntary-movement screen (AIMS) every six months for tardive dyskinesia.
• Movement side-effect check at each early visit.
• Prolactin if symptoms appear.
• Metabolic labs, weight, BMI, fasting glucose or HbA1c, and lipids at baseline and annually.
• Blood pressure at baseline and periodically.
• Liver function at baseline and if symptoms suggest a problem.

Metformin co-commencement: Aoife Carolan / Schizophrenia Bulletin guideline.

A clinical guideline led by Aoife Carolan strongly recommends co-commencing metformin alongside high-risk antipsychotics like olanzapine or clozapine. This proactive approach helps mitigate severe metabolic side effects, significantly reducing antipsychotic-induced weight gain and improving insulin resistance. The Schizophrenia Bulletin guideline states that when prescribing olanzapine or clozapine, metformin should be initiated immediately to prevent weight gain and cardiometabolic issues. Trifluoperazine is a first-generation antipsychotic and isn't on the automatic co-commencement list, but metformin is recommended if weight rises more than 3 percent of pre-medication weight or if other cardiometabolic risk factors are present.

Typical titration used in the guideline: 500 mg once daily, then 500 mg twice daily after one week, then 500 mg increments every two weeks as tolerated, up to 1000 mg twice daily by about week six. Contraindicated with eGFR below 30 mL/min/1.73 m². Renal function is checked annually and metformin is held during acute illness or dehydration.

Source: Carolan A, et al. Metformin for the Prevention of Antipsychotic-Induced Weight Gain: Guideline Development and Consensus Validation. Schizophrenia Bulletin. 2025;51(5):1193 to 1203.

What to expect

Common side effects

• Parkinsonism, tremor, slowness, stiffness.
• Akathisia.
• Acute dystonia.
• Mild sedation.
• Raised prolactin.
• Dry mouth (less than with low-potency phenothiazines).

Serious side effects and warnings

Boxed warning. Trifluoperazine carries the FDA boxed warning that antipsychotics increase the risk of death in older adults with dementia-related psychosis, and it isn't approved for that use.

• Tardive dyskinesia. Long-term antipsychotic use can produce involuntary movements. Risk rises with dose and duration.
• Neuroleptic malignant syndrome. Rare but serious. A medical emergency.
• Acute dystonic reactions, treatable and usually reversible.
• QTc prolongation at higher doses.
• Cholestatic jaundice, uncommon.

This isn't medical advice. Any concern about a serious side effect should be raised with a prescriber promptly.

Sexual side effects

Trifluoperazine can lower sex drive and cause erectile problems or delayed orgasm, partly through prolactin elevation. If sexual side effects appear, it's worth raising with the prescriber.

Weight, appetite, and sleep

Weight gain is usually modest. Sleep tends to be minimally affected. Some people find high-potency antipsychotics slightly activating; others find them slightly sedating.

Starting and dosing basics

This section is general background, not a dosing instruction. Trifluoperazine comes as tablets and an oral concentrate. It can be taken with or without food.

Missed doses and interactions

If you miss a dose, take it when you remember unless it's almost time for the next one, then skip and carry on. Don't double up. Trifluoperazine interacts with other CNS depressants, some antibiotics, and QT-prolonging drugs. The prescriber and pharmacist need a full list of medications and supplements. Alcohol worsens sedation.

Stopping and tapering

Don't stop trifluoperazine abruptly. A prescriber can step the dose down gradually.

Pregnancy and breastfeeding

Untreated psychosis carries its own risks in pregnancy, and trifluoperazine passes into breast milk. Anyone who's pregnant, planning a pregnancy, or breastfeeding should talk it through with their prescriber. This isn't medical advice.

Cost and generic availability

Trifluoperazine has been generic for decades. It's inexpensive and generally covered by insurance without difficulty.

Common questions

Why is trifluoperazine still used for anxiety? It rarely is anymore. The old anxiety indication is on the label, but SSRIs, SNRIs, buspirone, and benzodiazepines have almost entirely replaced antipsychotics for anxiety in modern practice. An antipsychotic wouldn't be a first, second, or third-line choice for typical anxiety.

How does it compare with haloperidol? They're similar in potency and in side-effect profile. Choice between them usually comes down to prescriber familiarity and prior response.

What about tardive dyskinesia risk? Real and cumulative with any long-term first-generation antipsychotic. AIMS screening every six months helps catch it early.

Do I need to worry about weight and blood sugar? Less than with the sedating atypicals like olanzapine, but changes still happen for some people. Annual labs are appropriate.

Questions to ask your prescriber

• What are we hoping this treats, and how will we know it's working?
• What movement side effects should I watch for?
• Should we plan for AIMS screening every six months?
• If side effects appear, what would we try next?
• If we decide to stop it later, how would we taper safely?

Sources

This guide draws on current prescribing information and public health references. It is reviewed for clinical accuracy and updated as guidance changes, and current as of June 8, 2026.

• U.S. Food and Drug Administration. Trifluoperazine prescribing information.
• MedlinePlus, U.S. National Library of Medicine. Trifluoperazine.
• National Institute of Mental Health. Mental health medications.
• American Psychiatric Association. Practice Guideline for the Treatment of Patients with Schizophrenia, 3rd edition.
• National Institute for Health and Care Excellence (NICE). CG178, Psychosis and schizophrenia in adults.
• Carolan A, et al. Metformin for the Prevention of Antipsychotic-Induced Weight Gain: Guideline Development and Consensus Validation. Schizophrenia Bulletin. 2025;51(5):1193 to 1203.