From the Guidelines
Chlorpromazine is indeed a typical antipsychotic medication. It belongs to the phenothiazine class of typical (first-generation) antipsychotics and works primarily by blocking dopamine D2 receptors in the brain, particularly in the mesolimbic pathway. This mechanism helps reduce positive symptoms of psychosis such as hallucinations and delusions.
Key Points
- Typical dosing ranges from 25-100 mg three times daily, with maintenance doses often between 200-800 mg per day, though individual needs vary.
- As a typical antipsychotic, chlorpromazine carries a higher risk of extrapyramidal side effects (movement disorders) compared to newer atypical antipsychotics, including parkinsonian symptoms, akathisia, dystonia, and tardive dyskinesia.
- It also commonly causes sedation, orthostatic hypotension, anticholinergic effects, and can potentially lead to neuroleptic malignant syndrome.
- Despite newer alternatives being available, chlorpromazine remains in use worldwide, particularly in resource-limited settings, due to its effectiveness and lower cost, as recommended by guidelines such as those from the World Health Organization 1.
Considerations
- The use of chlorpromazine should be carefully considered, weighing its benefits against its potential side effects, especially in comparison to atypical antipsychotics which may offer a more favorable side effect profile for many patients 1.
- Recent guidelines suggest that atypical antipsychotics may be preferred over typical antipsychotics like chlorpromazine due to their lower risk of extrapyramidal side effects and tardive dyskinesia 1.
- However, in settings where resources are limited, chlorpromazine may still be a viable option due to its lower cost and established efficacy 1.
From the FDA Drug Label
WARNING Increased Mortality in Elderly Patients with Dementia-Related Psychosis Elderly patients with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. ... Observational studies suggest that, similar to atypical antipsychotic drugs, treatment with conventional antipsychotic drugs may increase mortality. CLINICAL PHARMACOLOGY The precise mechanism whereby the therapeutic effects of chlorpromazine are produced is not known. The principal pharmacological actions are psychotropic.
- Chlorpromazine is classified as a conventional antipsychotic drug, which is also known as a typical antipsychotic.
- The FDA drug label 2 mentions conventional antipsychotic drugs, implying that chlorpromazine is a typical antipsychotic.
- Therefore, yes, chlorpromazine is a typical antipsychotic 2.
From the Research
Classification of Chlorpromazine
- Chlorpromazine is classified as a typical antipsychotic drug, also known as a first-generation antipsychotic 3, 4, 5.
- It is an aliphatic phenothiazine, which is one of the widely-used typical antipsychotic drugs 3.
Comparison with Atypical Antipsychotics
- Chlorpromazine has been compared to atypical antipsychotic drugs such as olanzapine, risperidone, and quetiapine in several studies 3.
- The studies found that chlorpromazine causes more extrapyramidal adverse effects compared to atypical antipsychotics, but the efficacy of chlorpromazine is similar to that of atypical antipsychotics in some cases 3, 6.
History and Development
- Chlorpromazine was the first antipsychotic drug introduced, and it has been used as a benchmark for comparing the efficacy of other antipsychotic drugs 4, 5.
- The drug has been in use for over 50 years, and it remains one of the most common drugs used for people with schizophrenia worldwide 5.
Side Effects and Adverse Effects
- Chlorpromazine is known to cause several side effects, including sedation, acute movement disorders, Parkinsonism, and low blood pressure with dizziness and dry mouth 6, 5, 7.
- The drug can also cause weight gain and other metabolic adverse effects, although the risk is generally lower compared to atypical antipsychotics 7.