Anti-Metabolites

Question 1

What enzyme does methotrexate bind?

Answer 1

Dihydrofolate reductase

Question 2

What product is not formed when dihydrofolate reductase is inhibited?

Answer 2

Tetrahydrofolate

Question 3

DHFR is an enzyme necessary in the production of what precursor molecule required for the S phase of DNA replication?

Answer 3

Purines

Question 4

What must occur for methotrexate to be eliminated?

Answer 4

Polyglutamation

Question 5

What is leucovorin used for?

Answer 5

Leucovorin can rescue the cell from the cytotoxicity of methotrexate

Question 6

What is the MOA of pemetrexed?

Answer 6

Inhibition of thymidylate synthase

Question 7

How can you reduce the extent of myelosuppression with pemetrexed?

Answer 7

Pre-treatment with B12 and folate

Question 8

What is the MOA of cytosine arabinoside?

Answer 8

S-phase pyrimidine analog- undergoes sequential phosphorylation until it is a triphosphate and then is incorporated into the DNA.

Inhibits DNA polymerase and therefore chain elongation

Question 9

How is cytosine arabinoside administered?

Answer 9

Approved for intrathecal administration

Question 10

Which anti-metabolite causes photosensitivity and hyperpigmentation of the palms?

Answer 10

5-FU

Question 11

5-FU can be replaced with which drug?

Answer 11

Capecitabine

Question 12

Which drug must be reduced when administered with allopurinol?

Answer 12

6-mercaptopurine