Which medication is indicated for psychosis or hallucinations of Parkinson's disease?

Which medication is indicated for psychosis or hallucinations of Parkinson's disease?

• A. Risperidone
• B. Olanzapine
• C. Haloperidol
• D. Clozapine

Answer: (D)

When treating psychosis or hallucinations in Parkinson’s disease, the goal is to control symptoms without making motor function worse. Clozapine fits this goal best because it can relieve psychotic symptoms while having a much lower risk of extrapyramidal side effects than typical antipsychotics. Its therapeutic effect in PD psychosis comes from its strong 5-HT2A antagonism and relatively low blockade of D2 receptors at standard doses, so it treats hallucinations without greatly impairing motor control. This is in contrast to drugs like haloperidol, which are potent D2 antagonists and tend to worsen Parkinsonian motor symptoms, and even other atypicals like risperidone or olanzapine, which can still contribute to motor side effects in some patients. Clozapine’s efficacy in PD psychosis is well-recognized, though it requires careful blood monitoring due to the risk of agranulocytosis and other potential adverse effects.

When treating psychosis or hallucinations in Parkinson’s disease, the goal is to control symptoms without making motor function worse. Clozapine fits this goal best because it can relieve psychotic symptoms while having a much lower risk of extrapyramidal side effects than typical antipsychotics. Its therapeutic effect in PD psychosis comes from its strong 5-HT2A antagonism and relatively low blockade of D2 receptors at standard doses, so it treats hallucinations without greatly impairing motor control. This is in contrast to drugs like haloperidol, which are potent D2 antagonists and tend to worsen Parkinsonian motor symptoms, and even other atypicals like risperidone or olanzapine, which can still contribute to motor side effects in some patients. Clozapine’s efficacy in PD psychosis is well-recognized, though it requires careful blood monitoring due to the risk of agranulocytosis and other potential adverse effects.