Cardiovascular drugs: hydralazine adverse effects: 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.

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Pharmacology · Cardiovascular drugs: hydralazine adverse effects

Sample item

A 50-year-old woman on hydralazine 200 mg per day for 8 months develops fever, arthralgia and pleuritic chest pain. Antinuclear and antihistone antibodies are positive, and anti-dsDNA is negative. Which factor most increases her susceptibility to this syndrome?

AGlucose-6-phosphate dehydrogenase deficiencyBPoor CYP2D6 metaboliser statusCSlow acetylator statusDRapid acetylator status

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

The answer and the reasoning

C. Slow acetylator status

Hydralazine is inactivated by N-acetyltransferase 2. Slow acetylators have higher drug exposure and are at greater risk of drug-induced lupus, typically with antihistone antibodies and sparing of the kidney and brain. The syndrome usually resolves on withdrawal, and the risk is dose related above about 200 mg per day.

Option by option

A. Glucose-6-phosphate dehydrogenase deficiency
G6PD deficiency predisposes to oxidative haemolysis, not to drug-induced lupus.
B. Poor CYP2D6 metaboliser status
Hydralazine is not metabolised mainly by CYP2D6; that enzyme handles drugs such as codeine and metoprolol.
C. Slow acetylator status (correct)
Correct. Reduced acetylation leaves more active drug and higher cumulative exposure.
D. Rapid acetylator status
Rapid acetylators clear the drug quickly and are less prone to lupus, although they may need higher doses.

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 C, Slow acetylator status. Hydralazine is inactivated by N-acetyltransferase 2.

Why is "Glucose-6-phosphate dehydrogenase deficiency" not the answer?

G6PD deficiency predisposes to oxidative haemolysis, not to drug-induced lupus.

Why is "Poor CYP2D6 metaboliser status" not the answer?

Hydralazine is not metabolised mainly by CYP2D6; that enzyme handles drugs such as codeine and metoprolol.

Why is "Rapid acetylator status" not the answer?

Rapid acetylators clear the drug quickly and are less prone to lupus, although they may need higher doses.

What concept does this question test?

It tests Cardiovascular drugs: hydralazine adverse effects in Pharmacology. Slow acetylators have higher drug exposure and are at greater risk of drug-induced lupus, typically with antihistone antibodies and sparing of the kidney and brain. The syndrome usually resolves on withdrawal, and the risk is dose related above about 200 mg per day.

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 Cardiovascular drugs: hydralazine adverse effects?

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.