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Prochlorperazine mesilate injection


Solution for injection containing prochlorperazine mesilate

Drugs List

  • prochlorperazine 12.5mg/1ml injection
  • STEMETIL 12.5mg/1ml injection
  • Therapeutic Indications


    Acute mania
    Schizophrenia and other psychoses
    Treatment of nausea and vomiting



    Treatment of nausea and vomiting
    Initial dose: 12.5mg by deep intramuscular injection. Follow by oral medication after 6 hours if considered necessary.

    Schizophrenia and other psychoses and acute mania
    Initial dose: 12.5mg to 25mg two or three times a day by deep intramuscular injection until conversion to oral therapy is possible.


    Use with caution, rate of metabolism and excretion of prochlorperazine decreases with age.

    Consider a reduced dose based on adult dose.


    Prochlorperazine injection is not licensed for use in children as it has been associated with dystonic reactions.

    Treatment of nausea and vomiting (unlicensed)
    Children aged 12 to 18 years
    12.5mg by intramuscular injection, given up to three times a day, if necessary.
    Children aged 5 to 12 years
    5mg to 6.25mg by intramuscular injection, given up to three times a day, if necessary.
    Children aged 2 to 5 years
    1.25mg to 2.5mg by intramuscular injection, given up to three times a day, if necessary.

    Patients with Renal Impairment

    Prochlorperazine should be avoided in patients with renal dysfunction.

    The Renal Drug Handbook recommends that patients with a glomerular filtration rate below 10 ml/minute be given small starting doses such as 5mg orally.


    Children under 2 years
    Central nervous system depression
    Prolactin-dependent neoplasm

    Precautions and Warnings

    Children aged 2 to 18 years
    Predisposition to prolongation of QT interval
    Prolonged starvation
    Benign prostatic hyperplasia
    Cardiac arrhythmias
    Cardiac disorder
    Cardiovascular disorder
    Cerebrovascular disorder
    Diabetes mellitus
    Epileptic disorder
    Haematological disorder
    Hepatic impairment
    History of agranulocytosis
    History of jaundice
    History of narrow angle glaucoma
    History of seizures
    Metabolic disorder
    Myasthenia gravis
    Organic brain syndrome
    Parkinson's disease
    Renal impairment
    Severe respiratory disease

    May mask symptoms of serious disease of the stomach and delay diagnosis
    Advise impaired alertness may affect ability to drive or operate machinery
    Not all available brands are licensed for all indications
    Patients at risk of arrhythmias perform ECG prior to initiating therapy
    Avoid contact of product with skin
    Do not use if solution is discoloured or particulates are apparent
    Local pain or nodule formation may occur after intramuscular administration
    Diabetic control may need adjustment
    Elderly more susceptible to sedation, hypotensive & temp regulatory effects
    Examine eyes for defects in prolonged use
    Monitor blood counts regularly
    Monitor ECG in patients at risk of QT prolongation
    Perform blood counts if unexplained infection or fever develops
    May cause postural hypotension especially in elderly
    May increase risk of seizure
    May precipitate diabetes mellitus
    Avoid abrupt withdrawal
    Discontinue at first signs of jaundice
    Discontinue if fever occurs
    Discontinue if patient develops neuroleptic malignant syndrome
    Reduce dose in elderly
    Advise patient to avoid alcohol during treatment
    Advise that effects are potentiated by CNS depressants (including alcohol)
    Advise patient that photosensitivity possible
    Advise patient to avoid exposure to direct sunlight

    Prochlorperazine may potentiate QT prolongation which is exacerbated by the presence of bradycardia or hypokalaemia. Use with caution, monitoring biochemical status and ECG of patients with congenital or acquired predisposing factors for prolonged QT interval e.g. cardiac disease, alcohol abuse, starvation and other metabolic abnormalities such as hypokalaemia, hypocalcaemia or hypomagnesaemia, particularly during the initial phase of treatment.

    Discontinue if jaundice occurs and use with caution in patients with a history of jaundice. A premonitory sign of an allergic hepato-biliary disorder manifesting as jaundice may be the sudden onset of fever after one to three weeks of treatment.

    Discontinue if patient develops an unexplained fever as this may be a sign of neuroleptic malignant syndrome (pallor, hyperthermia, autonomic dysfunction, altered consciousness, muscle rigidity). Signs of autonomic dysfunction such as sweating and arterial instability may precede the onset of hyperthermia and serve as early warning signs. Use with caution in organic brain disease and volume depleted patients - increased risk of neuroleptic malignant syndrome.

    Monitor full blood counts regularly. Agranulocytosis has been reported, occurrence of unexplained infections or fever may be evidence of blood dyscrasia and requires immediate haematological investigation.

    There is an increased susceptibility to CNS side effects, postural hypotension, hypothermia, hyperthermia and drug-induced parkinsonism in the elderly particularly after prolonged use. Use with caution in the elderly and patients with Parkinson's disease. Care should be taken not to confuse the adverse effects of prochlorperazine e.g. orthostatic hypotension, with the effects due to the underlying disorder.

    In schizophrenia response to prochlorperazine may be delayed. If treatment is withdrawn the recurrence of symptoms may not become apparent for some time.

    Pregnancy and Lactation


    Use prochlorperazine with caution in pregnancy.

    Prochlorperazine crosses the placenta. According to Briggs and co-workers, short courses of low dose prochlorperazine may be considered as safe for both mother and foetus despite isolated reports of congenital defects in children who had been exposed to prochlorperazine in utero. UK licensed product information however, recommends that prochlorperazine should be avoided during pregnancy. Product information further mentions possible adverse effects on the neonate. These include lethargy or paradoxical hyperexcitability, tremor and low apgar scores.

    Neuroleptics may occasionally prolong labour. It is then recommended that treatment is withheld until the cervix is dilated 3 to 4 cm.

    When neuroleptics have been used up to delivery, observation of neonate for at least 2 days is recommended. In order to prevent neonatal adaptation disorders, prescribers are advised to reduce the dose or even interrupt treatment in the days immediately preceding delivery. Neonates exposed to antipsychotic drugs during the third trimester are at risk of adverse effects including extrapyramidal and withdrawal symptoms such as agitation, hypertonia, hypotonia, tremor, somnolence, respiratory distress and feeding problems.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Prochlorperazine is contraindicated in breastfeeding.

    It is suspected that prochlorperazine, in line with other phenothiazines, will appear in breast milk. It cannot be excluded that the nursing infant would be exposed to prochlorperazine. UK licensed product information advises to stop breastfeeding during treatment.

    Use of prochlorperazine has been associated with galactorrhoea and hyperprolactinaemia.

    Infants of mothers who are breastfeeding while taking psychotropic medication should be monitored for adverse reactions.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Acute dystonias
    Atrial arrhythmia
    Atrioventricular block
    Autonomic instability
    Blood dyscrasias
    Blurred vision
    Cardiac arrhythmias
    Cholestatic jaundice
    Contact sensitisation
    Corneal opacities
    Decrease in bone mineral density
    Deep vein thrombosis (DVT)
    Difficulty in micturition
    Dry mouth
    ECG changes
    Extrapyramidal effects
    Gastro-intestinal disturbances
    Impaired consciousness
    Increased prolactin
    Interference with temperature regulation
    Lens opacities
    Menstrual disturbances
    Narrow angle glaucoma
    Nasal stuffiness
    Neuroleptic malignant syndrome
    Ocular changes
    Oculogyric crisis
    Postural hypotension
    Prolongation of QT interval
    Pulmonary embolism
    Purplish pigmentation of cornea, conjunctiva, retina
    Purplish pigmentation of skin
    Reflex tachycardia
    Respiratory depression
    Sexual dysfunction
    ST depression
    Sudden death reported
    T-wave changes
    Tardive dyskinesia
    U-wave changes
    Venous thrombosis
    Ventricular fibrillation
    Ventricular tachycardia
    Weight gain
    Withdrawal symptoms


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: October 2014

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 2nd edition (2007) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 9th edition (2011) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

    Medications and Mothers' Milk, 14th Edition (2010) Hale, T. Hale Publishing, Amarillo, Texas.

    The Renal Drug Handbook. 3rd edition. (2009) ed. Ashley, C and Currie, Radcliffe Publishing Ltd, Abingdon.

    Summary of Product Characteristics: Prochlorperazine 12.5mg/1ml injection. Antigen International Ltd. Revised December 2011

    Summary of Product Characteristics: Stemetil injection. Sanofi-Aventis. Revised August 2014

    NICE Evidence Services Available at: Last accessed: 14 September 2017

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Prochlorperazine Last revised: 7 September, 2013
    Last accessed: 14 October, 2014

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