**Question:** All are used for schizophrenia except -

A. Clozapine
B. Quetiapine
C. Risperidone
D. Haloperidol

**Core Concept:** Schizophrenia is a severe mental disorder characterized by disturbances in perception, thought, emotion, and behavior. The treatment of schizophrenia involves antipsychotic medications targeting dopaminergic neurotransmission in the brain.

**Why the Correct Answer is Right:** Haloperidol is a typical or first-generation antipsychotic (FGA) drug that works by antagonizing dopamine D2 receptors in the brain. Although it can be effective in managing some symptoms of schizophrenia, it is less effective than newer antipsychotic drugs like clozapine, quetiapine, and risperidone.

**Why Each Wrong Option is Incorrect:**

A. Clozapine: Atypical or second-generation antipsychotic (SGA), clozapine is highly effective for schizophrenia, particularly for patients with treatment-resistant schizophrenia. It has a lower risk of extrapyramidal side effects and tardive dyskinesia compared to FGAs.

B. Quetiapine: Another SGA, quetiapine is effective in treating schizophrenia symptoms. It has a broader spectrum of action, affecting multiple neurotransmitter systems, including dopamine, serotonin, and histamine.

C. Risperidone: Atypical antipsychotic drug, risperidone also targets multiple neurotransmitter systems, including dopamine, serotonin, and histamine. It is effective in treating schizophrenia symptoms and has a lower risk of extrapyramidal side effects compared to FGAs.

D. Haloperidol: As mentioned earlier, haloperidol is a typical antipsychotic drug with lower efficacy and higher risk of side effects compared to newer antipsychotic drugs like clozapine, quetiapine, and risperidone.

**Clinical Pearl:** When choosing an antipsychotic treatment for schizophrenia, clinicians typically opt for second-generation antipsychotics (clozapine, quetiapine, and risperidone) due to their superior efficacy, safety profile, and reduced extrapyramidal side effects. Haloperidol remains a valid option but is generally considered second-line therapy for patients with schizophrenia.

**Correct Answer:** Haloperidol is a first-generation antipsychotic (FGA) drug that was one of the first antipsychotics developed. Although it can be effective in treating schizophrenia symptoms, it has several limitations compared to second-generation antipsychotics (SGAs).