Medical Pharmacology: Chemotherapy Practice Questions

Folic acid antagonist: binds to catalytic site of dihydrofolate reductase-
1. altretamine (Hexalen)
2. cisplatin (Platinol)
3. methotrexate
4. fludarabine (Fludara)
Cellular mechanism(s) of resistance to the action of methotrexate:
1. reduce drug transport
2. increased polyglutamate formation
3. increased levels of dihydrofolate reductase
4. A & C
Most common mechanism of resistance to both 6-MP (6-mercaptopurine) and 6-TG (6-thioguanine):
1. increased levels of dihydrofolate reductase (DHFR)
2. increased drug efflux from the cells by increased active transport
3. decreased HGPRT activity
4. decreased polyglutamate formation
This pyrimidine analog is used systemically to treat adenocarcinomas, topically for skin cancer and works through inhibition of DNA synthesis.
1. cytarabine (ARA-C)
2. vinblastine (Velban)
3. fluorouracil (5-FU)
4. cladribine (Leustatin)
Leucovorin "rescue"
1. busulfan (Myleran)
2. mercaptopurine (Purinethol)
3. methotrexate
4. daunorubicin (DaunoXome)
Administrate of this drug concurrently with allopurinol can result in excessive toxicity;
1. thioguanine
2. mercaptopurine (Purinethol)
3. cytarabine (ARA-C)
4. fludarabine (Fludara)