Pharmacogenomics 3 & 4 Flashcards
The patients with the greatest area under the plasma concentration-time curve are those with which CYP2C19 phenotype?
A. Poor Metabolizer
B. Intermediate metabolizer
C. Extensive metabolizer
A. Poor Metabolizer
The same cure rates would probably be obtained doing this same study in a Caucasian population. T/F
False
Adverse effects of amoxicillin are increased in the subjects with the low activity variants of CYP2C19. T/F
False
Which of the following statements are rationale(s) given by the author for why subjects with the double mutant CYP2C19 genotype were more successfully treated than subjects with the other genotypes?
A. Omeprazole decreases gastric acid pH, increasing the stability of amoxicillin the stomach.
B. Omeprazole raises gastric acid pH, increasing the stability of amoxicillin the stomach.
C. The competition for omeprazole and amoxicillin CYP2C19 metabolism is decreased in subjects that are poor metabolizers.
D. The systemic availability of omeprazole is increased in persons with the poor
E. Omeprazole increases amoxicillin concentrations in gastric juices.
B. Omeprazole raises gastric acid pH, increasing the stability of amoxicillin the stomach.
D. The systemic availability of omeprazole is increased in persons with the poor
E. Omeprazole increases amoxicillin concentrations in gastric juices.
These authors were looking for an association between:
A. CYP2C19 genotype and incidence of gastric ulcer disease
B. CYP2C19 genotype and omeprazole AUC
C. CYP2C19 genotype and cure rate of H. pylori infection
D. CYP2C19 genotype and amoxicillin dose
C. CYP2C19 genotype and cure rate of H. pylori infection
What is S-mephenytoin 4’-hydroxylase? A. CYP2D6 B. CYP1A1 C. CYP2C19 D. CYP3A5
C. CYP2C19
Trastuzumab
What gene is being evaluated?
HER2 receptor not a gene
Trastuzumab
For which variant of that gene?
HER2 Receptor (Protein)(Overexpression of subclass of receptor than seen in non-tumor tissues).
Trastuzumab
How does the variant affect patient response to the drug?
a. You have to have HER2 receptors being highly expressed in order for Herceptin therapy to work.
i. If the protein is there and the receptor is present, the drug should work.
ii. Not overexpressed or not expressed at all - do not use this drug.
Trastuzumab
Are we genotyping the tumor or the patient?
. We are genotyping the tumor to see if the tumor expresses the HER2
a. NOT genotyping the patient
b. We are trying to get this drug to interact with the TUMOR based on receptors present
Trastuzumab
Are we doing this genotyping to ensure efficacy or prevent toxicity?
to ensure efficacy of Herceptin therapy
Trastuzumab
Are we genotyping or doing cytology studies (looking at the presence of cell surface receptors using immunohistochemistry for example?
We are doing cytology studies (looking for the presence of cell receptors, specifically the HER2 receptors to see if there is overexpression.) Not looking at DNA sequence
Trastuzumab
Does the FDA say what genotyping test to use?
HER2 Testing, FDA approved. Use different tests depending on whether it is breast cancer or gastric cancer.
Not a specific company, just use a product that is FDA approved.
Trastuzumab
Is there a particular patient population or tumor type that should be genotyped?
breast or gastric/gastroesophageal adenocarcinoma
Nursing mothers.
Trastuzumab
How do genotyping results affect clinical use of the drug or clinical care of the patient?
If there is an overexpression of the HER2 receptor, then use the drug.
Not overexpressed or not expressed at all - do not use this drug.
Abacavir
What gene is being evaluated?
HLA-B
Abacavir
For which variant of that gene?
HLA-B*5701
Abacavir
How does the variant affect patient response to the drug?
Potential hypersensitivity reaction- fatal