Pharmacogenetics Flashcards
1
Q
Define pharmacokinetics and pharmacodynamics
A
Pk= What the body does to the drug Pd= What the drug does to the body
2
Q
How can genetic variation effect drug?
A
- Absorption
- Activation
- Altered target
- Catabolism
- Excretion
3
Q
How is Thiopurine methyltransferase be a problem with drug metabolism?
A
- Inactivates certain drugs
- Includes Azathioprine (immunosuppressant), 6-mercaptopurine & 6-thioguanine (chemo)
- Gene polymorphisms reduce enzyme protein activity
- Severe toxicity if both copies of the gene have the variant
4
Q
How can N-Acetyltransferase activity be a problem in drug metabolism?
A
- Liver enzymes inactivating drugs by acetylation
- Fast & slow acetylators
- Slow acetylators inc risk of side effects
5
Q
How is Succinylcholine a problem in drug metabolism?
A
- Related to poison curare
- Muscle relaxant
- Rare gene variant homozygotes have reduced butyrylcholinesterase activity
- Effects may last hours can cause death without ventilation
6
Q
How is warfarin a problem in drug metabolism?
A
- Oral anticoagulant to reduce embolism/thrombosis
- Decreases availability of it K
- Dose too low= patient remains at risk
- Dose too high= risk of haemorrhage
7
Q
What is Trastuzumab (Herceptin) and what patients is it used in?
A
- Monoclonal antibody for HER2 receptor
- Used in the 20% of breast cancers which have over-expression of HER2
8
Q
Why are BRAF inhibitors used for treating melanomas?
A
- Melanoma resistant to chemo
- 50% melanomas have somatic mutation in BRAF gene
9
Q
Name some new genetic testing technologies and what they can potentially idenntify
A
- SNP chips
- Next generation sequencing
- Genetic variations for multiple genes/ polymorphisms or whole genome
