Pharmacogenetics Flashcards
What is pharmacogenetics?
The study of genetic variation in relation to drug response.
What is pharmacodynamics?
What the drug does to your body.
What is pharmacokinetics?
What your body does to the drug.
-i.e. metabolism
What is personalised medicine?
Therapies tailored to the individual.
What is stratified medicine?
Selecting therapies for groups of patients with shared biological characteristics.
NB what is the difference between germline and somatic mutations?
Germline are hereditary, somatic are acquired.
What proportion of UK hospital admissions are related to adverse drug reactions?
6.5%.
What effect does thiopurine have on drug metabolism?
Inactivates certain drugs, causing toxicity.
-e.g. azathioprine (immunosuppressant)
What are N-acetlytransferase?
Liver enzymes that inactivate drugs by acetylation.
- SNP variation alters speed
- e.g. isonazid (TB drug)
What is succinylcholine?
Muscle relaxant used in anaesthesia.
-related to curare (poison)
What gene mutations alter succinylcholine activity?
BCHE gene variants.
- reduced butyrylcholinesterase activity
- effects last hours instead of minutes
What causes aminoglycoside induced hearing loss?
G>A mutation in mitochondrial MT-RNR1 gene.
- aminoglycosides more likely to bind
- maternal inheritance
Optimum warfarin dose varies 20x between individuals. What genes explain 50% of this variability? (2)
- Cytochrome P450 (CYP2C9)
- Vitamin K oxidoreductase complex 1 (VKORC1)
Why might it be helpful to test for polymorphisms before treatment?
May reduce adverse effects and hospital admissions.
-personalised therapy
What effect does Trastuzumab have on breast cancer?
Antibody against HER2 receptor.
- effective in patients with HER2 overexpression (20%)
- can be detected using FISH
