Lecture 23 : Introduction to Pharmacogenomics Flashcards
(11 cards)
Pharmacokinetics
Fate of drug in body
Pharmacodynamics
Effects of drug on body
Pharmacogenetics
Study of individual gene-drug interactions, usually being 1 or 2 genes having dominant effect on drug response.
Relatively simple, straightforward relationship
Pharmacogenomics
Study of WHOLE genomic influence on drug response, using high-throughput data
More complex interactions
What is haemolytic anemia (example)
- Disease where RBCs are destructed
- Triggered by infections, high stress, fava beans, certain meds such as antimalarials, aspirin
- Most common in Africa, Mediterranean and asiatic populations
What is G6PD deficiency
- Highest freq in malarial regions
- Hundreds of variations
- Seen more in men than in women (X linked)
- However helps against malaria?
Suxamethonium Apnoea (chloride)
- Nicotinic acetylcholine receptor AGONIST
- Non-competitively binds at synaptic junction to receptors
- Cant be reversed by drugs
- Wears off slowly til drug is eliminated / excreted
- Fast acting depolarising muscle relaxant, can induce paralysis
- ANAESTHETIC
CYtochrome P450 CYP2D6
- Metabolises around 25% of drugs commonly used clinically
- THE ONLY DRUG METABOLISING CYP ENZYME that is NON-INDUCIBLE
- Highly polymorphic (lots of variations)
Probe drugs can test for people’s phenotypes, caucasians have less CYP2D6 (5-10% of them have polymorphisms), so DEBRISOQUINE and SPARTEINE are drugs that can can test this, because they are metabolised by CYP2D6
Ultrarapid metabolisers, Extensive, intermediate and poor metabolisers
Applies to lots of P450 enzymes.
CYP3A5 is a HIGH METABOLISER
Genetic Variation in Enzymes generally speaking
Limitations of tests of drugs
