antimetabolites

Question 1

antimetabolites

Answer 1

They are folate analogs or nucleic acid analogs. inhibit enzymes. Act in S phase. Cell Cycle Specific.

Question 2

Methotrexate

Answer 2

Folate Analog

Inhibits DHFR. purine synth down and thymidine synthesis down.

Use: Childhood ALL and choriocarcinoma. Osteosarcoma. Breast Ovarian, bladder, head & neck, and Burkitts lymphoma. Meningeal leukemia and Meningeal metastasis.

Side Effects: Hepatic toxicity, Renal toxicity, reproductive issues

Misc: Leucovorin can help with side effects

Question 3

Pemtrexed

Answer 3

Folate Analog

Polyglutamate form that Inhibits DHFR and Thymidine Synthase.

Use: lung, mesothelioma, colon, pancreatic

Question 4

5-FU

Answer 4

Pyramidine analog

Becomes 5-UMP (inhibits TS) and 5-UTP (added into RNA) with addition of ribose and phosphate.

Use: Head & Neck, Breast, Gastric, Pancreatic, Colorectal, Cervical. Basal Cell Carcinoma

Side Effects: Cardiac toxicity. Hand and Foot Syndrome.

Misc: Leucovorin can potentiate. Very volatile so have to give IV

Question 5

Capetabine

Answer 5

Pyramidine Analog

Metabolized to 5-FU.

Use: Breast and Pancreatic.

Side Effects:—

Misc: —-

Question 6

Cytarabine

Answer 6

Pyramidine Analog

Metabolized from Ara-C to Ara-CMP (by deoxycytidine kinase) and then to Ara-CTP. Ara-CTP is incorporated into DNA.

Use: ALL, CLL, AML

Side Effects: —-

Question 7

Gemcitabine

Answer 7

Pyramidine Analog

Converted by deoxycytidine kinase from dFdC to dFdCMP->dFdCDP->dFdCTP. dFdCDP inhibits deoxyribonucleotide reductase and dFdCTP is incorporated into DNA.

Use: Pancreatic. Lung, Ovarian, Bladder, and Head & Neck.

Side Effects: Flu like symptom

Question 8

6-Mercaptopurine

Answer 8

Purine Analog

Converted by hypoxanthine-guanine blahblah to TIMP. Blocks de novo purine synthesis. Blocks AMP and XMP from IMP. Also incorporated into DNA.

Use: keeps ALL in remission

SIde Effects: Hepatoxicity

Misc: interacts with allopurinol which inhibits xanthine oxidase. results in 6-MP increase.