Which medication is classified as a typical antipsychotic?: An Overview of First-Generation Antipsychotics

October 11, 2025 •

4 min read

First-generation antipsychotics, commonly known as typical antipsychotics, work primarily by blocking dopamine D2 receptors in the brain. This class of medication, which includes haloperidol and chlorpromazine, has been used since the 1950s to manage symptoms of psychosis and other severe mental health conditions. Understanding which medication is classified as a typical antipsychotic is crucial for navigating treatment options for disorders like schizophrenia.

Quick Summary

An exploration of typical antipsychotic medications, including prominent examples, their mechanism of action, key clinical uses, and comparison with newer atypical counterparts. It also examines their side effect profile and how they differ from second-generation drugs in treating psychotic symptoms.

Key Points

Haloperidol is a typical antipsychotic: Commonly known by its brand name Haldol, haloperidol is a widely used first-generation antipsychotic.
Dopamine blockade is the mechanism: Typical antipsychotics work by blocking dopamine D2 receptors in the brain, which helps reduce positive symptoms of psychosis.
High risk of movement side effects: A significant drawback of typical antipsychotics is their propensity to cause extrapyramidal symptoms (EPS) and tardive dyskinesia.
Used for schizophrenia and other disorders: Typical antipsychotics are indicated for conditions like schizophrenia, Tourette's syndrome, and severe agitation.
Examples include Chlorpromazine and Fluphenazine: In addition to haloperidol, other medications like chlorpromazine (low potency) and fluphenazine (high potency) are also classified as typicals.
Individualized treatment is crucial: Due to varying side effect profiles and patient responses, the choice between typical and atypical antipsychotics is highly personalized and requires careful medical supervision.

What is a typical antipsychotic?

Typical antipsychotics are a class of medications also referred to as first-generation antipsychotics (FGAs) or conventional antipsychotics. These drugs were the first to be developed for the treatment of psychosis and work primarily by inhibiting dopaminergic neurotransmission in the brain. Their main therapeutic effect is achieved by blocking the dopamine D2 receptors in the brain's mesolimbic pathway. This mechanism is most effective for managing the "positive symptoms" of schizophrenia, which include hallucinations, delusions, and disorganized thinking.

Examples of common typical antipsychotics

Several medications are classified as typical antipsychotics, differing mainly in their potency and side effect profiles. They are often categorized based on their strength of D2 receptor blockade and corresponding risk of side effects.

High-Potency Typical Antipsychotics:

Haloperidol (Haldol): One of the most widely known typical antipsychotics, used for schizophrenia, Tourette's syndrome, and severe agitation.
Fluphenazine (Prolixin): Available in oral and long-acting injectable forms for treating schizophrenia.
Trifluoperazine (Stelazine): Used to treat schizophrenia and some cases of severe anxiety.

Medium-Potency Typical Antipsychotics:

Perphenazine (Trilafon): Can treat schizophrenia as well as severe nausea and vomiting.
Loxapine (Adasuve): Used for schizophrenia treatment.

Low-Potency Typical Antipsychotics:

Chlorpromazine (Thorazine): One of the first antipsychotics discovered, used for schizophrenia, manic-depression, nausea, and persistent hiccups.
Thioridazine (Mellaril): Primarily for schizophrenia when other medications are ineffective.

How typical antipsychotics work

The primary mechanism of typical antipsychotics involves blocking dopamine D2 receptors. The overactivity of dopamine in certain brain regions is thought to cause psychotic symptoms. By blocking these receptors, typical antipsychotics reduce the influence of dopamine, leading to a reduction in the severity of hallucinations, delusions, and other positive symptoms. While effective against positive symptoms, the mechanism of action also contributes to a higher risk of motor-related side effects compared to newer atypical antipsychotics. The specific dosage is often titrated to achieve optimal efficacy, typically aiming for 65-80% D2 receptor blockade, while minimizing the risk of adverse effects.

Key differences: typical vs. atypical antipsychotics

In recent years, the use of atypical (second-generation) antipsychotics has become more common, largely due to their different side effect profiles. The following table outlines some of the key distinctions between the two generations.


Feature	Typical Antipsychotics (First-Generation)	Atypical Antipsychotics (Second-Generation)
Mechanism of Action	Primarily blocks dopamine D2 receptors.	Blocks both dopamine (D2) and serotonin (5-HT2A) receptors.
Symptom Coverage	More effective at treating positive symptoms (hallucinations, delusions).	Effective at treating both positive and negative symptoms (social withdrawal, apathy).
Movement Side Effects	Higher risk of Extrapyramidal Symptoms (EPS), including tardive dyskinesia.	Lower risk of EPS and tardive dyskinesia.
Metabolic Side Effects	Lower risk of metabolic issues like weight gain and diabetes.	Higher risk of metabolic side effects and significant weight gain.
Cost	Generally less expensive.	Often more expensive due to newer patents.

Potential side effects and management

Patients taking typical antipsychotics are at a significant risk for several side effects, which must be closely monitored and managed by a healthcare provider. High-potency typicals are particularly associated with movement disorders due to their strong D2 blockade in the nigrostriatal pathway.

Common Side Effects:

Extrapyramidal Symptoms (EPS): This can include acute dystonia (painful muscle contractions), akathisia (restlessness), and parkinsonism (tremor, stiffness). These can often be managed with adjunctive medications or by adjusting the dose.
Tardive Dyskinesia (TD): A more serious and potentially irreversible condition involving involuntary, repetitive body movements, such as grimacing and tongue protrusion. The risk of TD is a major reason why typicals are not the first choice for long-term therapy.
Anticholinergic Effects: Low-potency typicals, with their higher affinity for muscarinic receptors, can cause side effects like dry mouth, blurred vision, constipation, and urinary retention.
Sedation: Particularly common with low-potency typical antipsychotics.
Neuroleptic Malignant Syndrome (NMS): A rare but life-threatening condition characterized by muscle rigidity, high fever, and altered mental status. It requires immediate medical intervention.

Due to these potential risks, the selection of an antipsychotic involves careful consideration of the patient's specific symptoms, tolerance for side effects, and overall treatment goals. Treatment plans are highly individualized and often involve regular monitoring of the patient's physical and mental health. The lowest effective dose is generally recommended to minimize side effect risks.

Conclusion

Which medication is classified as a typical antipsychotic? The answer includes a range of first-generation drugs, with haloperidol and chlorpromazine being two prominent examples. These medications work primarily by blocking dopamine receptors and have been effective in treating the positive symptoms of psychotic disorders for decades. However, their use is associated with a higher risk of extrapyramidal side effects compared to newer atypical antipsychotics. Modern treatment guidelines favor a holistic approach, weighing the efficacy against the side effect profile for each patient's unique needs. Further research into novel antipsychotic mechanisms continues to advance the field. For comprehensive information on the different generations of antipsychotics, one can refer to the National Center for Biotechnology Information (NCBI) for detailed pharmacology reports: Antipsychotic Medications - NCBI Bookshelf.

Frequently Asked Questions

Typical (first-generation) antipsychotics primarily block dopamine D2 receptors and are more likely to cause movement-related side effects. Atypical (second-generation) antipsychotics block both dopamine and serotonin receptors, generally resulting in fewer movement side effects but a higher risk of metabolic issues like weight gain.

Common examples include haloperidol (Haldol), chlorpromazine (Thorazine), fluphenazine (Prolixin), and perphenazine (Trilafon).

The main use is to treat psychotic disorders, particularly the positive symptoms of schizophrenia, such as hallucinations and delusions. They are also used for other conditions like Tourette's syndrome and severe agitation.

Typical antipsychotics work by antagonizing, or blocking, dopamine D2 receptors in the brain. This action helps to reduce the overactivity of dopamine that is believed to cause psychotic symptoms.

Side effects can include extrapyramidal symptoms (EPS) like muscle stiffness, restlessness (akathisia), and involuntary movements (tardive dyskinesia). Other effects can include sedation, dry mouth, blurred vision, and weight gain, though metabolic effects are more common with atypicals.

Yes, they are still used, particularly for managing acute agitation or in cases where other treatments have been ineffective. However, atypical antipsychotics are often preferred for long-term maintenance due to a more favorable movement-related side effect profile.

No, typical antipsychotics are generally not very effective for treating the negative symptoms of schizophrenia, such as social withdrawal and lack of motivation. Atypical antipsychotics are considered more effective for these symptoms.