Pharmacology - Antimetabolites

Question 1

How do you reverse the effects of MTX?

Answer 1

leucovorin (folinic acid)

Question 2

How do you reverse the effects of 5-fluorouracil?

Answer 2

thymidine “rescue”

Question 3

What is the main toxicity of both MTX and 5-fluorouracil?

Answer 3

myelosuppression

Question 4

Side fx include: myelosuppression, macrovesicular fatty change in the liver, mucositis, and teratogenicity.

Answer 4

MTX

Question 5

Side fx include: myelosuppression and photosensitivity.

Answer 5

5-FU

Question 6

5-FU is ______ analog.

Answer 6

pyrimidine

Question 7

MTX is a ______ analog.

Answer 7

folic acid

Question 8

What phase of the cell cycle do antimetabolites work in?

Answer 8

S phase

Question 9

Name a purine analog used to treat leukemias and lymphomas.

Answer 9

6-mercaptoPURINE

Question 10

What drug can increase the toxicity of 6-mercaptopurine? Why?

Answer 10

Allopurinol b/c 6-MP is metabolized by xanthine oxidase.

Question 11

Name the purine analog used mainly to treat ALL.

Answer 11

6-thioguanine

Question 12

How are the purine analog drugs 6-MP and 6-TG activated in vivo?

Answer 12

By HGPRT.

Question 13

What is the mechanism of action of cytarabine (ara-C)?

Answer 13

pyrimidine analog that inhibits DNA polymerase