Tardive dyskinesia is least common with –
**Core Concept**
Tardive dyskinesia is a side effect of long-term use of antipsychotic medications, characterized by involuntary, repetitive body movements that are often irreversible. It is caused by dopamine receptor blockade, particularly in the nigrostriatal pathway.
**Why the Correct Answer is Right**
The correct answer is related to the pharmacological properties of antipsychotic medications. Tardive dyskinesia is less common with atypical antipsychotics, which have a lower affinity for dopamine D2 receptors and a higher affinity for serotonin 5-HT2A receptors. This is because the serotonin-dopamine interaction helps to mitigate the risk of dopamine receptor blockade. Additionally, atypical antipsychotics tend to have a more balanced effect on dopamine and serotonin receptors, which reduces the risk of tardive dyskinesia.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because typical antipsychotics, such as haloperidol, are more likely to cause tardive dyskinesia due to their high affinity for dopamine D2 receptors.
**Option B:** This option is incorrect because clozapine, an atypical antipsychotic, is not the least common cause of tardive dyskinesia; rather, it has a lower risk compared to typical antipsychotics.
**Option C:** This option is incorrect because depot antipsychotics, which are long-acting injections, can increase the risk of tardive dyskinesia due to prolonged dopamine receptor blockade.
**Option D:** This option is incorrect because antipsychotic polypharmacy, which involves combining multiple antipsychotics, can increase the risk of tardive dyskinesia due to cumulative dopamine receptor blockade.
**Clinical Pearl / High-Yield Fact**
When prescribing antipsychotic medications, it is essential to consider the risk of tardive dyskinesia and weigh it against the benefits of treatment. Atypical antipsychotics are generally preferred for long-term use, but close monitoring for extrapyramidal symptoms is still necessary.
**Correct Answer:** B. Clozapine.