Largactil is a sedative

ChlorpromazineDrug groupsNeurolepticsPhenothiazine Chlorpromazine is an antipsychotic, calming and antiemetic agent from the group of phenothiazines, which is mainly used to treat psychotic disorders. The effects are based on the antagonism of dopamine receptors and various other receptors. The drugs are given up to four times a day. Possible adverse effects include tiredness, low blood pressure, dry mouth, dizziness, constipation, rash, eye deposits, hand tremors, and movement disorders. Chlorpromazine can increase the QT interval. Withdrawal should be gradual in order to prevent withdrawal reactions.

synonymous: Chlorpromazinum, Chlorpromazini hydrochloridumPhEur, Chlorpromazinhydrochlorid, CPZ


Chlorpromazine was commercially available in various oral and parenteral dosage forms (e.g. Chlorazin®, Thorazine®, Largactil®, Megaphen®). It was first used in the 1950s as one of the first synthetic antipsychotics. Today there are no longer any pharmaceuticals registered in Switzerland. Chlorpromazine is still on the market in some countries.

Structure and properties

Chlorpromazine (C.17H19ClN2S, Mr = 318.9 g / mol) is present in medicinal products as chlorpromazine hydrochloride, a white, crystalline powder that is very easily soluble in water. It is a chlorinated dimethylamine derivative of phenothiazine and structurally belongs to the phenothiazines.


Chlorpromazine (ATC N05AA01) has antipsychotic, antiemetic, calming and depressant properties. The effects are based, among other things, on the antagonism of dopamine receptors, adrenoceptors, muscarinic, histamine and serotonin receptors. Chlorpromazine has a long half-life of around 30 hours.

Mechanism of action of neuroleptics, click to enlarge. Illustration © PharmaWiki


Chlorpromazine is mainly used to treat psychotic disorders such as schizophrenia. There are also other areas of application such as nausea, vomiting, porphyria, tetanus, states of excitement and restlessness.


According to the specialist information. The dose is determined individually and gradually. The medicine is given up to four times a day. Withdrawal should take place gradually to prevent the development of withdrawal symptoms such as nausea, vomiting, dizziness and tremors.


Chlorpromazine is contraindicated in cases of hypersensitivity, intoxication with alcohol or central depressant drugs, liver diseases, low blood pressure and glaucoma. The complete precautionary measures can be found in the product information sheet.


Drug interactions have been described with the following substances, among others:

unwanted effects

Possible adverse effects include tiredness, low blood pressure, dry mouth, dizziness, constipation, rash, eye deposits, tremors in the hands, restlessness in the legs, movement disorders (dyskinesia), chest discharge, menstrual disorders, and erectile dysfunction. Chlorpromazine can increase the QT interval and cause abnormal heart rhythms.

see also

Phenothiazines, neuroleptics

  • Adams C.E. et al. Chlorpromazine for schizophrenia: a Cochrane systematic review of 50 years of randomized controlled trials. BMC Med, 2005, 17, 3, 15 Pubmed
  • Ahmed U., Jones H., Adams C.E. Chlorpromazine for psychosis induced aggression or agitation. Cochrane Database Syst Rev, 2010, CD007445 Pubmed
  • Pharmaceutical product information (CH, USA)
  • European Pharmacopoeia PhEur
  • swell

Conflicts of Interest: None / Independent. The author has no relationships with the manufacturers and is not involved in the sale of the products mentioned.

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This article was last changed on 5/21/2020.
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