CNS drugs and antiepileptics: antipsychotics and prolactin: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Pharmacology · CNS drugs and antiepileptics: antipsychotics and prolactin

Sample item

A 25-year-old woman with schizophrenia on an antipsychotic develops galactorrhoea and amenorrhoea. Serum prolactin is markedly raised and imaging of the pituitary is normal. Which antipsychotic is most likely responsible?

AClozapineBRisperidoneCQuetiapineDAripiprazole

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Risperidone

Dopamine from the hypothalamus inhibits prolactin release, so potent D2 blockade raises prolactin. Risperidone and typical antipsychotics cause marked hyperprolactinaemia. Aripiprazole is a partial D2 agonist that can lower prolactin, and clozapine and quetiapine bind D2 loosely and seldom raise it.

Option by option

A. Clozapine
Clozapine has a weak D2 affinity and rarely raises prolactin.
B. Risperidone (correct)
Correct. Strong D2 blockade in the tuberoinfundibular pathway raises prolactin.
C. Quetiapine
Quetiapine dissociates rapidly from D2 receptors and seldom raises prolactin.
D. Aripiprazole
Aripiprazole is a partial D2 agonist and tends to reduce prolactin.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, Risperidone. Dopamine from the hypothalamus inhibits prolactin release, so potent D2 blockade raises prolactin.

Why is "Clozapine" not the answer?

Clozapine has a weak D2 affinity and rarely raises prolactin.

Why is "Quetiapine" not the answer?

Quetiapine dissociates rapidly from D2 receptors and seldom raises prolactin.

Why is "Aripiprazole" not the answer?

Aripiprazole is a partial D2 agonist and tends to reduce prolactin.

What concept does this question test?

It tests CNS drugs and antiepileptics: antipsychotics and prolactin in Pharmacology. Risperidone and typical antipsychotics cause marked hyperprolactinaemia. Aripiprazole is a partial D2 agonist that can lower prolactin, and clozapine and quetiapine bind D2 loosely and seldom raise it.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study CNS drugs and antiepileptics: antipsychotics and prolactin?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.