Medical Pharmacology: Cancer Chemotherapy Drugs: Anti-Metabolites Practice Questions

Azacitidine (Vidaza):
1. Along with decitibine. Azacitidine exhibits antileukemic activity.
2. Azacitidine inhibits DNA cytosine methyltransferase.
3. Both the citabine and azacitidine may be used in treatment of myelodysplasia.
4. A & B
5. B & C
6. A & C
7. A, B & C
Azacitidine (aza-nucleosides in general):
1. Azacitidine uses the "human eequilibrative transporter" to enter human cells.
2. Aza-nucleosides following DNA incorporation covalently bind to cytosine methyltransferase, which, because of intracellular enzyme depletion, results in both DNA demethylation and ultimately apoptosis.
3. Both
4. Neither
Azacitidine (aza-nucleosides) major toxicities:
1. Mild G.I. symptoms
2. Myelosuppression
3. Both
4. Neither
Gemcitabine (Gemsar) is related to deoxycytidine as the drug is a difluoro analog.
1. True
2. False
Gemcitabine (Gemzar):
1. Gemcitabine is sequentially phosphorylated to a triphosphate nuclear form.
2. Gemcitabine triphosphate incorporation into DNA prevents more than a single additional nucleotide addition, thus causing chain termination.
3. Both
4. Neither
More likely to exhibit anti-cancer activity against solid tumors.
1. Cytarabine
2. Gemcitabine
3. Both
4. Neither
Gemcitabine: primary dose-limiting toxic reaction is myelosuppression (neutropenia).
1. True
2. False
Concerning gemcitabine pharmacokinetics:
1. Mainly determined by hepatic and plasma (as well as other organs) deamination reactions.
2. Wide variance in clearance across individuals; however, clearance appears unaffected by renal failure.
3. Both
4. Neither
Gemcitabine administrationresults in radiosensitization and generally should not be used with radiotherapy.
1. True
2. False
Resistance to gemcitabine may be related to expression and/or activity of the human equilibrative nucleoside transporter (hENT1).
1. True
2. False