Repeated USMLE Questions Step 1- 266

A 12-year-old girl visits her physician for follow up after treatment with methotrexate for acute lymphoblastic leukemia. Stool analysis reveals blood in stool. Her platelet count is very low.

Which of these substances should be administered immediately?

A-Vitamin K






This is a case of methotrexate toxicity. Leucovorin is the active form of folic acid and it reverses methotrexate toxicity except neurotoxicity. Vitamin K is used in cases of bleeding due to defect in coagulation factors. Deferoxamine is the drug used in iron overdose. Amitriptyline is a tricyclic antidepressant and it has no role in methotrexate toxicity. Penicillamine is used in Wilson’s disease and some other metal toxicities.

The correct answer is B

3 thoughts on “Repeated USMLE Questions Step 1- 266”

  1. Since methotrexate also causes hepatotoxicity, can’t it cause Vitamin K dependent coagulation defects as well and hence blood in stool?

  2. Absolutely correct Dr Hamda. Thank you for your comment.

  3. Leucovorin is the active form of folic acid .that is sutible medicine.

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