Products
Chlorpromazine was commercially available in various oral and parenteral dosage forms (e.g., Chlorazine, Thorazine, Largactil, Megaphene). It was first used in the 1950s as one of the first synthetic antipsychotics. Today, it is no longer a registered drug in many countries. In some countries, chlorpromazine is still on the market.
Structure and properties
Chlorpromazine (C17H19ClN2S, Mr = 318.9 g/mol) is present in drugs as chlorpromazine hydrochloride, a white crystalline powder that is very soluble in water. It is a chlorinated dimethylamine derivative of phenothiazine and structurally belongs to the phenothiazines.
Effects
Chlorpromazine (ATC N05AA01) has antipsychotic, antiemetic, sedative, and depressant properties. Effects include antagonism at dopamine receptors, adrenoceptors, muscarinic, histamine, and serotonin receptors. Chlorpromazine has a long half-life of approximately 30 hours.
Indications
Chlorpromazine is mainly used to treat psychotic disorders such as schizophrenia. In addition, other indications include nausea, vomiting, porphyria, tetanus, agitation, and restlessness.
Dosage
According to the SmPC. The dose is determined individually and gradually. The drug is administered up to four times daily. Discontinuation should be gradual to prevent the development of discontinuation symptoms such as nausea, vomiting, dizziness, and tremor.
Contraindications
Chlorpromazine is contraindicated in hypersensitivity, intoxication with alcohol or central depressant drugs, liver disease, low blood pressure, and glaucoma. For complete precautions, see the drug label.
Interactions
Drug-drug interactions have been described with the following substances, among others:
- Alcohol
- Central depressant drugs
- Antihypertensive drugs
- Anticoagulants
- Pentetrazol
- Levodopa
- Stimulants
Adverse effects
Possible adverse effects include fatigue, low blood pressure, dry mouth, dizziness, constipation, skin rash, deposits in the eye, tremors of the hands, restlessness of the legs, movement disorders (dyskinesias), breast secretions, menstrual irregularities, and potency disorders. Chlorpromazine may prolong the QT interval and cause cardiac arrhythmias.
