Question

Methotrexate toxicity can be prevented by:

• A. \( \text{Leucovorin} \)
• B. \( \text{Mesna} \)
• C. \( \text{Oncovin} \)
• D. \( \text{Na}_2\text{S}_2\text{O}_3 \)

Hint:

Leucovorin "rescue" protects normal tissues while allowing methotrexate to exert its anti-cancer effects.

Answer 1

The Correct Option is A

Leucovorin (folinic acid) is used to prevent methotrexate toxicity by rescuing healthy cells from its effects. Methotrexate inhibits dihydrofolate reductase, leading to folate depletion; leucovorin bypasses this blockade. It is administered in high-dose methotrexate therapy to mitigate adverse effects.