CHEMOTHERAPY OF NEOPLASTIC DISEASES 2

Question 1

Who are the antimetabolites

Answer 1

FOLATE ANALOGS
PURINE ANALOGS
PYRIMIDINE ANALOGS

Question 2

Who are the purine analogs

Answer 2

6-MERCAPTOPURINE

6-THIOGUANINE

Question 3

6-MERCAPTOPURINE is a thick analog of ________

Answer 3

6-MERCAPTOPURINE is a thick analog of hypoxanthine

Question 4

6-MERCAPTOPURINE: MOA

Answer 4

• Converted to thio-IMP by the salvage pathway enzyme, HGPRT.
• Thio-IMP inhibits the first step of the de novo purine ring biosynthesis.
• Thio-IMP also blocks formation of AMP and GMP from IMP.
• Also, dysfunctional RNA and DNA result from incorporation of guanylate analogs.

Question 5

HGPRT IS absent in which syndrome

Answer 5

Leash nyhan syndrome

Question 6

6 mercaptopurine is metabolized to thiouric acid by_________

If _________ is given to reduce hyperuricemia, dose of 6-MP must be decreased to avoid accumulation of the drug b/c xanthine oxidase is blocked

Answer 6

6 mercaptopurine is metabolized to thiouric acid by xanthine oxidase

If alopurinol is given to reduce hyperuricemia, dose of 6-MP must be decreased to avoid accumulation of the drug

Question 7

6-MERCAPTOPURINE: ADVERSE EFFECTS

Answer 7

• Nausea, vomiting, diarrhea.
• Bone marrow suppression.
• Hepatotoxicity.

Question 8

What does 6 thioguanine do

Answer 8

Converted to the nucleotide, which then inhibits purine synthesis and the phosphorylation of GMP to GDP.

Question 9

Which drug is Used for acute nonlymphocytic leukemias.

Answer 9

6 thioguanine

Question 10

• 6-mercaptopurine and 6-thioguanine are also metabolized by ?

Answer 10

• 6-mercaptopurine and 6-thioguanine are also metabolized by the enzyme thiopurine methyltransferase (TPMT).
• Patients who have weak activity TPMT are at increased risk for severe toxicities such as myelosuppression.

Question 11

Who are the pyrimidine analogs

Answer 11

5-Fluorouracil

Cytarabine