93 out of 100
Which of the following is an antimetabolite(LQ)
Ans. A Methotrexate
A. Methotrexate - Antimetabolite
B. Vinblastine - Vinka alkaloids - Natural alkaloids
C. Cisplatin - Platinum coordinated compounds – Alkylating agents
Etoposide - Epipodophyllotoxins.
A few points about Methotrexate.
- It acts by inhibiting DHFRase. It is a pseudo irreversible inhibition because methotrexate has 50000 times affinity than the normal substrate.
- It kills in S-phase cell cycle. Primarily affects DNA synthesis but also affects RNA & protein synthesis.
- Major toxicity of methotrexate is pancytopenia which is reversed by folinic acid.