Trifluoperazine: Formula, Presentation, Indications, Mechanism of Action, Dosage, Side Effects and Interactions

It is a derivative of phenothiazine and a dopamine antagonist with antipsychotic and antiemetic activities.

Trifluoperazine exerts its antipsychotic effect by blocking the central receptors of dopamine, thus avoiding effects such as delusions and hallucinations caused by an excess of dopamine.

This agent also functions as an inhibitor of calmodulin, which leads to the elevation of cytosolic calcium.

It is an oral antipsychotic medication used for the treatment of schizophrenia.

Trifluoperazine is one of the oldest first generation antipsychotic medications. Examples of other first generation antipsychotics include:

  • Proclorperazina (Compazine, Compro, Procomp).
  • Clorpromazina (Promapar, Thorazine).
  • Perfenazine (Trilaphone).
  • Tioridazina (Mellaril).

Chemical formula

  • C21H24F3N3S.

Presentation

  • Tablets of 1, 2, 5 and 10 mg of Trifluoperazine.

Indications

This medication is indicated in the treatment of mental disorders such as schizophrenic psychosis, psychosomatic disorders, behavioral disorders, borderline personality disorders and as anxiolytic and antiemetic in low doses.

Mechanism of action

Although the exact mechanism of antipsychotics is unknown, scientists believe they can work by blocking the action of dopamine in the brain.

Dopamine is a neurotransmitter (chemical) that the nerves use to communicate with each other. Trifluoperazine is used when patients do not respond to other antipsychotics.

Dose

  • The recommended initial dose of trifluoperazine for the treatment of schizophrenia is 1 to 5 mg every 12 hours.
  • The typical maintenance dose is 15 to 20 mg daily, and the maximum daily dose is 40 mg.
  • The dose to treat anxiety is 1 to 2 mg every 12 hours.
  • The maximum dose is 6 mg daily.

Trifluoperazine should not be used to treat anxiety for longer than 12 weeks.

Side effects

Side effects have been reported such as excessive sleep, which tends to disappear after several days following treatment.

Another common side effect is the symptoms of akathisia, as well as the appearance of some mild skin reactions.

Also some patients have experienced dry mouth, amenorrhea,  insomnia , muscle weakness, fatigue, blurred vision and nausea.

When the high doses are administered, there are usually some symptoms such as neutropenia , agranulocytosis, cholestatic jaundice , anemia and hepatitis.

There may also be hypotension , myocardial depression, syncope , seizures and parkinsonism, worsening of glaucoma and an increase or decrease in blood glucose.

Although it is extremely rare, in some patients, tardive dyskinesia may appear and the neuroleptic malignant syndrome may be the result of treatment with trifluoperazine.

These side effects can be so serious that you should seek emergency medical attention.

Warnings and contraindications

The use of trifluoperazine during pregnancy has not been adequately studied.

Neonates exposed to antipsychotics during the third trimester of pregnancy are at risk of having extrapyramidal symptoms and abstinence after birth.

The reported symptoms included agitation, hypertonia , hypotonia , tremor, drowsiness, depressed breathing and eating disorder.

The safe use of trifluoperazine by nursing mothers has not been established.

That is why, its use must be restricted during pregnancy and lactation.

Trifluoperazine is contraindicated in comatose states or in patients with very pronounced depressions caused by depressants of the central nervous system.

It is also contraindicated when the patient presents blood dyscrasias, depression of the bone marrow and in pre-existing liver disorders, as well as in cases of renal failure, untreated epilepsy and Parkinson’s disease.

Interactions

When you combine trifluoperazine with medications such as procainamide (Pronestyl), sotalol (Betapace), amiodarone  (Cordarone), and dofetilide (Tikosyn’s) that affect your heart rhythm and can cause abnormal heartbeats.

Antidepressants such as fluoxetine (Prozac), sertraline (Zoloft) and tricyclic antidepressants can reduce the breakdown of trifluoperazine, which leads to an increase in blood levels and more side effects of trifluoperazine.

Trifluoperazine should be used with caution with medications that depress the central nervous system and cause sedation or drowsiness.

Examples include alprazolam (Xanax), lonazepam (Klonopin), zolpidem (Ambien), codeine and morphine.

Such combinations may cause excessive sedation, drowsiness, weakness, confusion, impaired speech and, in severe cases, a coma or death.

The combination of alcohol and trifluoperazine may increase the risk of low blood pressure .

Trifluoperazine decreases its absorption when it is administered comitantly with medications such as antacids, cholinergics, coffee or tea.

This drug is used with caution in patients with heart disease, with hypertrophy of the prostate  and the presence of glaucoma .

In the case of extrapyramidal symptoms, these can easily be reversed with the use of anticholinergics, but without administering it simultaneously with trifluoperazine.