Prochlorperazine: Price, Dosage & Where to Buy

Prochlorperazine is a phenothiazine antipsychotic medicine used to control severe nausea and vomiting, a principal use listed on its label. It is also used for schizophrenia and short-term generalised non-psychotic anxiety, although it is not usually the first treatment chosen for that anxiety. Prochlorperazine requires a prescription in the United Kingdom, and generic versions are available.

Prochlorperazine is used to control severe nausea and vomiting. Its label also lists treatment of schizophrenia and short-term treatment of generalised non-psychotic anxiety. For anxiety, it is not usually the first medicine chosen because some risks associated with it are not shared by common alternative treatments.

Evidence for its anxiety use does not establish that it helps other conditions where anxiety or similar symptoms occur, such as physical illness or agitated depression. Prochlorperazine is not approved for dementia-related psychosis, and its effectiveness has not been shown for behavioural complications in people with intellectual disability.

Phenothiazine antipsychotics act mainly by blocking the effects of dopamine, a chemical messenger involved in communication between nerve cells. Blocking dopamine signals in areas of the brain involved in triggering vomiting can reduce nausea and vomiting. Effects on dopamine signalling elsewhere in the brain contribute to their antipsychotic action.

Because dopamine also helps regulate movement, this action can cause unwanted muscle stiffness, restlessness or involuntary movements. The medicine's effects are not limited to the pathways involved in the symptoms being treated.

The label lists oral tablets and film-coated oral tablets in strengths of 5 mg and 10 mg, and rectal suppositories of 25 mg. The label lists the usual adult oral dosage for severe nausea and vomiting as 5 mg or 10 mg, 3 or 4 times daily. The label lists daily dosages above 40 mg for resistant cases only.

The label lists the usual oral dosage for non-psychotic anxiety as 5 mg, 3 or 4 times daily, with a limit of 20 mg per day and a treatment duration no longer than 12 weeks. The usual starting dose is 10 mg, 3 or 4 times daily, for moderate to severe psychotic disorders in hospitalised or adequately supervised adults.

Treatment is individualised according to response and the severity of the condition. The label describes more gradual dosage increases in elderly, debilitated or emaciated patients, with close monitoring of elderly patients because of susceptibility to low blood pressure and neuromuscular reactions.

For a missed scheduled dose, follow the directions on the dispensing label or ask a pharmacist. General pharmacy advice is to resume the usual schedule if the next dose is nearly due, rather than doubling a dose. Advice may differ when the medicine is prescribed only when needed.

The label does not specify general pregnancy safety data or breastfeeding information. It states that if neuromuscular reactions occur in a pregnant patient, treatment should be stopped and not restarted. Discuss pregnancy, plans for pregnancy or breastfeeding with a doctor or pharmacist so that treatment can be reviewed.

The label specifies storage at 20° to 25°C, protected from light, in a tight, light-resistant container. Keep the medicine in its labelled container to maintain quality and keep it out of children's reach.