DNA Synthesis Inhibitors/Deoxyribonucleotide Synthesis Inhibitors

Question 1

6-Mercaptopurine

Answer 1

AKA: 6-MP

Type: DNA Synthesis Inhibitor

MOA: inhibits denovo purine synthesis

AE:
1. Hepatotoxicity

DDI:
1. Allopurinol
2. Febuxostat (absolute CI)

Question 2

Methotrexate

Answer 2

AKA: MTX

Type: DNA Synthesis Inhibitor & Deoxyribonucleotide Synthesis Inhibitor

MOA:
1. inhibits DHF-Reductase –> inhibition of thymidylate synthase
2. inhibits denovo purine synthesis

AE:
1. Hepatotoxicity (BBW)
2. BM Suppression (BBW)

CI: Pregnancy (BBW) (used with misoprostol for pregnancy termination)

Leucovorin rescue therapy to limit toxicity

Question 3

5-Fluoruracil

Answer 3

AKA: 5-FU

Type: Deoxyribonucleotide Synthesis Inhibitor

MOA: inhibits thymidylate synthase

AE:
1. Hand-foot syndrome (skin toxicity)

Question 4

Capecitabine

Answer 4

*oral prodrug of 5-FU

Type: Deoxyribonucleotide Synthesis Inhibitor

MOA: inhibits thymidylate synthase

AE:
1. Hand-foot syndrome (skin toxicity)

Question 5

Hydroxyurea

Answer 5

MOA: inhibits ribonucleotide reductase