Chemotherapy: rituximab and hepatitis B: 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 · Chemotherapy: rituximab and hepatitis B

Sample item

A 60-year-old man with diffuse large B-cell lymphoma is to start rituximab-based chemotherapy. HBsAg is negative, anti-HBc total is positive and anti-HBs is negative. What is the best step?

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

The answer and the reasoning

B. Start antiviral prophylaxis such as entecavir or tenofovir before chemotherapy

Rituximab depletes B cells and carries a high risk of hepatitis B reactivation in patients with past infection (anti-HBc positive), even when HBsAg is negative. Prophylaxis with entecavir or tenofovir is started before treatment and continued for at least 12 months after it ends. Reactivation can cause fulminant hepatic failure.

Option by option

  • A. No action, since HBsAg is negative

    A negative HBsAg does not exclude occult infection with reactivation risk.

  • B. Start antiviral prophylaxis such as entecavir or tenofovir before chemotherapy (correct)

    Correct. Prophylaxis prevents reactivation during profound B-cell depletion.

  • C. Give hepatitis B vaccine alone

    Vaccination will not respond in time and does not prevent reactivation of latent virus.

  • D. Start peginterferon for two weeks before chemotherapy

    Interferon is myelosuppressive and not used as prophylaxis.

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.

More Pharmacology questions

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, Start antiviral prophylaxis such as entecavir or tenofovir before chemotherapy. Rituximab depletes B cells and carries a high risk of hepatitis B reactivation in patients with past infection (anti-HBc positive), even when HBsAg is negative.

Why is "No action, since HBsAg is negative" not the answer?

A negative HBsAg does not exclude occult infection with reactivation risk.

Why is "Give hepatitis B vaccine alone" not the answer?

Vaccination will not respond in time and does not prevent reactivation of latent virus.

Why is "Start peginterferon for two weeks before chemotherapy" not the answer?

Interferon is myelosuppressive and not used as prophylaxis.

What concept does this question test?

It tests Chemotherapy: rituximab and hepatitis B in Pharmacology. Prophylaxis with entecavir or tenofovir is started before treatment and continued for at least 12 months after it ends. Reactivation can cause fulminant hepatic failure.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. 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 Chemotherapy: rituximab and hepatitis B?

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.