What is Chlorpromazine (Thorazine)?

From the Guidelines

Chlorpromazine (Thorazine) is a phenothiazine antipsychotic medication.

Key Characteristics

• It can be used to treat nausea/vomiting, intractable hiccups, and agitated patients 1
• Chlorpromazine has anticholinergic properties, which may worsen the condition of patients with intoxication from drugs with anticholinergic properties or anticholinergic delirium 1
• It is a low-potency antipsychotic agent, which tends to produce more anticholinergic side effects, including sedation and potential deficits in memory 1

Clinical Use

• Chlorpromazine is approved for acute mania in adults, but it is generally not used as a first-line agent 1
• It may be considered for treatment-refractory cases of schizophrenia or bipolar disorder, under the supervision of mental health professionals 1
• The medication should be used with close clinical observation, cardiorespiratory monitoring, pulse oximetry, and/or electrocardiogram to monitor for potential cardiac adverse effects, such as QTc prolongation 1

Important Considerations

• Chlorpromazine should be prescribed at a time, and antipsychotic combination treatment may be considered only when necessary, under close clinical monitoring 1
• Anticholinergics should not be used routinely to prevent extrapyramidal side effects, but may be considered for short-term use in cases of significant side effects 1

From the FDA Drug Label

CLINICAL PHARMACOLOGY The precise mechanism whereby the therapeutic effects of chlorpromazine are produced is not known. The principal pharmacological actions are psychotropic. It also exerts sedative and antiemetic activity. DESCRIPTION Chlorpromazine hydrochloride, USP, a dimethylamine derivative of phenothiazine, has a chemical formula of 2-chloro-10-[3-(dimethylamino) propyl] phenothiazine monohydrochloride.

Chlorpromazine, also known as Thorazine, is a dimethylamine derivative of phenothiazine with psychotropic, sedative, and antiemetic properties. Its chemical formula is 2-chloro-10-[3-(dimethylamino) propyl] phenothiazine monohydrochloride 2 2.

• Key characteristics:
  • Chemical formula: C17H19ClN2S. HCl
  • Molecular weight: 355.33 g/mol
  • Principal pharmacological actions: psychotropic, sedative, and antiemetic activity

From the Research

Overview of Chlorpromazine

• Chlorpromazine, also known as Thorazine, is a first-generation antipsychotic drug that was introduced in the 1950s 3, 4.
• It is used to treat schizophrenia and other psychotic disorders, and is listed as one of the essential medicines by the World Health Organization 5.
• Chlorpromazine works by blocking dopamine receptors in the brain, which helps to reduce psychosis and other symptoms of schizophrenia 3, 4.

History and Development

• Chlorpromazine was first synthesized in 1951 and became available for prescription in France in 1952 4.
• Its introduction revolutionized the treatment of schizophrenia and paved the way for the development of other antipsychotic drugs 4, 6.
• The discovery of chlorpromazine also led to a greater understanding of the role of chemical messaging in neurotransmission and reduced the stigma associated with mental illness 6.

Pharmacology and Efficacy

• Chlorpromazine is a dopamine blocker that reduces psychosis regardless of the underlying diagnosis 3.
• The efficacy of chlorpromazine has been studied in several clinical trials, which have shown that it is effective in reducing symptoms of schizophrenia 5.
• However, the optimal dosage of chlorpromazine is still a topic of debate, and studies have shown that lower doses may be just as effective as higher doses 5.

Administration and Bioavailability

• Chlorpromazine can be administered orally or through a topical gel formulation 7.
• However, studies have shown that the bioavailability of chlorpromazine from a topical gel formulation is low, and it may not be an effective treatment option 7.
• The pharmacokinetics of chlorpromazine have been studied, and it is known to have a long half-life and to be metabolized by the liver 6.

Side Effects and Adverse Effects

• Chlorpromazine can cause a range of side effects, including extrapyramidal symptoms, weight gain, and sedation 3, 5.
• The risk of side effects is higher with higher doses of chlorpromazine, and studies have shown that lower doses may be associated with fewer side effects 5.
• The adverse effects of chlorpromazine have been studied, and it is known to have a range of potential adverse effects, including neuroleptic malignant syndrome and tardive dyskinesia 6.