Transcript Your pharmacogenotyping blood test showed that codeine

PHARMACOGENOMICS:
PERSONALIZING DRUG THERAPY AT
INDIANA UNIVERSITY HEALTH
Brian Decker MD, PharmD, MS
Janet S. Carpenter, PhD, RN, FAAN
Jennifer L. Milata, MSN, RN, ACNS-BC
OBJECTIVES
1.
2.
3.
Describe a new Personalized Medicine initiative
at IU Health
Discuss why personalized medicine is important
to patient care
Discuss nursing considerations related to the
new Personalized Medicine initiative at IU Health
NEW PERSONALIZED MEDICINE INITIATIVE
AT IUH
For a growing list of medications, a
patient’s pharmacogenotype
determines drug response and
adverse drug effects.
IU Health subspecialty medicine clinics
will be able to determine the
pharmacogenotypes of clinic patients.
The long-term goal is to make
pharmacogenotyping routine care at
IUH clinics
WHAT IS PHARMACOGENOTYPING?
 Simple
blood draw
 Results identify variations in human
genes regulating drug disposition,
especially drug-metabolizing enzymes
 Variations can alter a person’s ability
to metabolize certain drugs
 Different therapeutic responses to
drugs
 Adverse drug events
WHAT ARE GENETIC VARIATIONS?

Most common type of genetic
variation is a single
nucleotide polymorphism
(SNP or “snip”)


See figure: Cytosine (C)
changes to thymine (T) which
changes the base pairs from
cytosine and guanine (CG) to
thymine and adenine (TA)
SNPs alter a person’s ability
to metabolize certain drugs
THE PERSONALIZED MEDICINE INITATIVE
TARGET DRUG LIST

Amitryptyline

Esomeprazole

Tacrolimus

Aripiprazole

Ezetimibe/simvastatin

Thioguanine

Atazanavir

5-Fluorouracil

Tramadol

Atomoxetine

Glyburide

Venlafaxine

Azathioprine

Lansoprazole

Voriconazole

Capcitabine

Mercaptopurine

Warfarin

Citalopram

Nortriptyline

Clopidogrel

Omeprazole

Codeine

Pantoprazole

Doxepin

Phenytoin

Efavirenz

Rasburicase

Escitalopram

Simvastatin
IUH PERSONALIZED MEDICINE CLINIC WORK-FLOW
Patients will be
identified when
prescribed 1 of
the 38 target
drugs for the
first time
Computer “popup” will alert the
clinician of the
availability of
pharmacogenetic
testing for this
medication
Medical
Record
Pharmacogenotyping
test done
Data collected and analyzed for patient morbidity, mortality, quality and cost
Follow Morbidity, Mortality, Quality, Cost
Automatic
Consult
NURSING CONSIDERATIONS
Consent
Patient Education
Patients must
consent to
pharmacogenotyping; Explain why a dosing
Consent will be
adjustment or drug
obtained by research change was made
nurses
Medications
Be alert to and verify
atypical drug doses;
Regularly monitor and
report adverse
effects; Know the
Personalized
Medicine Target Drug
list.
Documentation
Clarify and verify drug
doses; Document
patient education
efforts; Document
response to
medications.
CASE STUDY
Mrs. Jones was seen in an IU Health outpatient
clinic and consented for pharmacogenotyping.
Results show a SNP in her CYP2D6 drug
metabolizing enzymes. She is a poor metabolizer
of CYP2D6 drugs such as codeine, tramadol,
dextromethorphan, fluoxetine, paroxetine,
venlafaxine, and citalopram. These drugs should
be avoided because they are not well
metabolized.
CASE STUDY CONT.
Mrs. Jones asks why her codeine was stopped
and another medication was started. Which is
the best response?
A. Your pharmacogenotyping blood test
showed that codeine was not likely to be
effective for you.
B. Your pharmacogenotyping blood test
showed that you were allergic to codeine.
C. Your pharmacogenotyping blood test
showed that you were likely to have a lot
of side effects from the codeine.
CASE STUDY: CORRECT RESPONSE
 A:
Your pharmacogenotyping blood
test showed that codeine was not
likely to be effective for you.
 This answer is correct.
 Codeine is metabolized by the
CYP2D6 enzyme to morphine.
 Because she cannot metabolize
codeine well, she will not get
effective pain relief.
CASE STUDY: INCORRECT RESPONSES
B: Your pharmacogenotyping blood test showed that
you were allergic to codeine.
 Being unable to metabolize a drug is not the same
as being allergic to a medication.
 C: Your pharmacogenotyping blood test showed that
you were likely to have a lot of side effects from the
codeine.
 Because the drug is poorly metabolized, minimal
side effects would be expected. If
pharmacogenotyping had shown Mrs. Jones was
an ultra-rapid metabolizer, she would be at greater
risk for side effects from codeine.

SUMMARY
Personalized Medicine at IU Health is a new
initiative.
Pharmacogenotyping results will be used to
personalize medications to optimize drug
efficacy and minimize side effects.
Nurses need to be aware of personalized
medication selection and dosing adjustments
that may result from pharmacogenotyping
Improved
Patient
Outcomes