Pharmacogenomic Testing

Question 1

PGx testing & pharmacist action

Abacavir

Triumeq, Epzicom

Answer 1

HLA-B*5701

at risk of hypersensitivty
test all patient prior to starting

if positive don’t use

Question 2

PGx testing & pharmacist action

Allopurinol

Zyloprim, Aloprim

Answer 2

HLA-B*5801

increased risk of SJS
d/c @ first sign of allergic rxn

if positive, don’t use

Question 3

PGx testing & pharmacist action

Tegretol
Trileptal
Dilantin
Cerebyx

Carb, Ox, Pheny, Fos

Answer 3

HLA-B*1502

risk of SJS and TEN
test all asian patients before starting Tegretol

if postive, don’t use

Question 4

Identify CYP polymorphisim and pharmacist action

Plavix

Clopidogrel

Answer 4

CYP2C19

Plavix is a prodrug
CYP2C19 2** or **3 are PM

CYP2C192** or **3, consider alternative

Question 5

Identify CYP polymorphisim and pharmacist action

Codeine

Answer 5

CYP2D6

Codeine is a prodrug
CYP2C19 2** or **3 are PM

CYP2C19 2** or **3 , consider alternative

Question 6

Identify CYP polymorphisim and pharmacist action

Coumadin, Jantoven

warfarin

Answer 6

CYP2C9
VKORC1

CYP2C9 2** OR **3

Lower dose

Question 7

Identify PGx testing & pharmacist action

Herceptin

Trastuzumab

Answer 7

HER2

require overexpression of HER2 for efficacy

If tumor is HER2 (-), drugs are not effective

Question 8

Identify PGx testing & pharmacist action

Erbitux

Cetuximab

Answer 8

KRAS mutation

only patients who are KRAS mutation (-) should receive these medications

if positive, do not use

Question 9

Identify PGx testing & pharmacist action

AZA

Azathioprine (Azasan, Imuran)

Answer 9

TPMT

low/absent TPMT activity ↑ the risk of myelosuppression

If TPMT low/absent, start at a very low dose or use alternative

Question 10

Identify PGx and pharmacist action

Xeloda

Capecitabine or Fluorouracil

Answer 10

DPD deficiency

↑risk of severe toxicity

If DPD deficient, do not use