MCQ – 79005

Correct Answer » B Explanation

Detailed Explanation:

Clinical Reasoning for the Correct Answer:
– Clozapine is an atypical antipsychotic well known for its risk of agranulocytosis, a potentially life-threatening decrease in neutrophils requiring regular blood monitoring.
– Haloperidol, a typical antipsychotic, does not typically cause agranulocytosis.
– Therefore, agranulocytosis is a distinguishing adverse effect of clozapine compared to haloperidol.

Why Option A is Incorrect: Weight gain
– Both clozapine and haloperidol can cause weight gain, but it is more prominent with atypical antipsychotics like clozapine.
– However, weight gain is common among many atypical antipsychotics and thus not as uniquely distinguishing as agranulocytosis.

Why Option C is Incorrect: Sedation
– Clozapine can cause sedation due to its antihistaminergic and anticholinergic effects.
– Haloperidol may cause sedation but usually to a lesser extent than clozapine.
– Sedation is not as specific a side effect to differentiate these drugs compared to agranulocytosis.

Why Option D is Incorrect: Severe extrapyramidal symptoms (EPS)
– Haloperidol, a high-potency typical antipsychotic, is well known for causing severe extrapyramidal symptoms (e.g., Parkinsonism, dystonia).
– Clozapine causes minimal EPS due to its action on multiple neurotransmitter pathways and weak D2 receptor blockade.
– Therefore, severe EPS is much more characteristic of haloperidol than clozapine.

Differential Side Effect Profiles
– Agranulocytosis → clozapine only.
– Severe EPS → haloperidol only.
– Weight gain and sedation → more common with clozapine but also possible with others.