Feng, Xiaodong_ Xie, Hong-Guang - Applying pharmacogenomics in therapeutics-CRC Press (2016)

174 Applying Pharmacogenomics in Therapeutics
d. Carboplatin and cisplatin are activated through the CYP2B6 enzyme.
e. Higher levels of ERCC1 protein will cause less oxaliplatin ototoxicity.
2. Match the following chemotherapies with its PGx biomarkers
Chemotherapy
Oxaliplatin
Cyclophosphamide
Dabrafenib
Irinotecan
Tamoxifen
6-MP
Methotrexate
Capecitabine
Biomarkers
a. MTHFR
b. G6PD
c. UGT1A1
d. DPD
e. CYP2B6
f. CYP2D6
g. TPMT
h. ERCC1
3. What is the current recommendation for a patient who is treated with
FOLFIRI (5-FU, leucovorin, and irinotecan) who is homozygous for
UGT1A1*28?
4. What is the clinical recommendation for a patient who is being treated with
6-MP, and is heterozygous for TPMT?
a. Start with the normal dose, then allow 2 weeks to reach steady state
before adjusting dose.
b. Start with 25% of normal dose, then allow 4 weeks to reach steady state
before adjusting dose.
c. Start with 25% of normal dose, then allow 6 weeks to reach steady state
before adjusting dose.
d. Start with 50% of normal dose, then allow 4 weeks to reach steady state
before adjusting dose.
e. Start with 50% of normal dose, then allow 6 weeks to reach steady state
before adjusting dose.
5. Consider the following statements:
I. Deficiency of CYP2D6 activities causes less toxicities in tamoxifen,
such as hot flashes.
II. Majority of the biomarkers for drug toxicity are drug transporters.
III. Patients with heterozygote DPD activity treated with 5-FU should be
treated with 50% dose reduction.
IV. Decreased GST activity is associated with decrease in cyclophosphamide
toxicity.
V. ALDH3A1*2 allele variant causes increased risk of hemorrhagic cystitis
in patients.
Which of the above statements are true?
a. I, II, III, IV
b. I. III, V
c. I, IV, V
d. II, III, V
e. II and IV