Metotrimeprazine is used in the treatment of psychosis, particularly those associated with schizophrenia and the manic phase of bipolar disorder.

It is also used for treating anxiety, sleep disorders, nausea or vomiting and pain.


What is Metotrimeprazine?


Metotrimeprazine is an antipsychotic. Its effect is mainly due to its action as an antagonist of the dopamine neurotransmitter receptors in the brain. It is also thought that its ability to bind to the receptors 5-HT2 serotonin contributes to its mechanism of action. It exerts a calming, relaxing and pain-relieving effect.


How should Metotrimeprazine be taken?


Metotrimeprazine can be administered orally, by intramuscular injections or by infusion directly into a vein.


Side effects associated with Metotrimeprazine


Metotrimeprazine can increase the levels of blood sugar and those of prolactin. Moreover, it can cause painful and prolonged erections, neuroleptic malignant syndrome and tardive dyskinesia. Finally, it may be associated with QT prolongation and increase the risk of heat stroke as well as the skin’s sensitivity to the sun.


Among the other possible adverse effects are included:


  • Dizziness
  • Drowsiness
  • Constipation
  • Dry mouth
  • Tarnished vision
  • Difficulty passing urine
  • Weight gain


It is important to contact a doctor immediately if taking Metotrimeprazine triggers any of the following symptoms:


  • Rash
  • Urticaria
  • Difficulty breathing
  • Tightness in the chest
  • Swelling of the mouth, face, lips, or tongue
  • Spasms or muscle stiffness
  • Tremors
  • Restlessness
  • Unusual face expression (like a mask)
  • Drooling from the mouth
  • Bleeding and bruising
  • Symptoms of an infection in progress
  • Nausea, vomiting or persistent loss of appetite
  • Stomach or abdominal pain
  • Jaundice
  • Pain, swelling or sudden reddening
  • Fainting
  • Severe dizziness
  • Convulsions
  • Persistent diarrhea
  • Blood or mucus in the stool


Contraindications and warnings associated with the use of Metotrimeprazine


Before taking Metotrimeprazine it is important to tell your doctor if:


  • You have any allergies to the active substance, to other components, any other drug, food or other substances
  • You are taking other medications, herbal remedies and supplements, in particular drugs that may prolong the QT interval (such as dronedarone and pimozide) and medicines that make you sleepy (such as antihistamines and muscle relaxants)
  • You suffer (or have suffered) from blood disorders, severe depression of the central nervous system, liver disease, pheochromocytoma, glaucoma, heart problems, Parkinson's disease, seizures and difficulty urinating
  • You are pregnant or breastfeeding


Moreover, it is important to inform physicians, surgeons or dentists about ongoing treatment with Metotrimeprazine prior to any procedure.


Lastly, the treatment may impair the ability to drive or operate hazardous machinery.