Pharmacogenetics and pharmacokinetics Flashcards
(46 cards)
What is polymorphisms?
Genetic variation within a population
What SNPs stand for?
Single nucleotide polymorphisms
What occurs in synonymous SNP?
Both alleles of a gene encode the same polypeptide
What occurs in non synonymous SNP?
The alleles encode a different polypeptide
How can pharmacogenetics be described?
The study of how individual patient’s genome affects their response to a drug
How does inheritance affect the a patient’s response to a drug?
Inheritance can affect the efficacy and adverse events of patients
What are the differences between monogenic and polygenic?
- Monogenic - a single gene affects the response
- Polygenic - multiple genes affect the response
What is suxamethonium used for?
- Causes relaxation of muscles/ can be used to facilitate surgery
What is isoniazid used for?
-Treatment of TB
What is the major ADR that can occur when using Isoniazid?
-peripheral neuropathy
What enzyme metabolises Isoniazid?
N-acteyl transferase 2 (NAT2)
How does NAT2 work?
It transfers an acetyl group onto the isoniazid, which inactivates isoniazid
How many SNPs alleles are known for isoniazid?
27
What are fast and slow acetylators?
- Fast acetylators : are patients that can efficiently metabolise isoniazid
- Slow acetylators : Patients that metabolise isoniazid more slowly
Which catageroy of patients slow or fast acetylators are at greater risk of peripheral nerve damage?
Slow acetylators
What other drug is also metabolised by NAT2 and what is is used to treat?
Procainamide - used to treat arrythmias
What causes patients to have reduced 2D6 P450 ACTIVITY?
Allele encodes enzyme with comprimised catalytic activity, causing deletion of gene
What are patients at risk of when suxamethonium is degraded slowly?
Prolonged paralysis
What occurs when patients have reduced 2D6 function, and provide examples?
- They have increased response to drugs that are metabollically inactivated by 2D6. e.g nortryptyline
- They also get a decreased response to pro-drugs that are activated by 2D6. E.g codeine and tamoxifen
2D6 genotype can influence survival of breast cancer patients receiving tamoxifen. TRUE OR FALSE?
TRUE
Patients with increased 2D6 P450 activity do not have multiple copies of 2D6 and are ultrarapid metabolizers. TRUE OR FALSE?
FALSE
What is 6-mercaptopurine used to treat?
-Cytotoxic chemotherapy for leukaemia
What does the antimetabolite of 6-mercaptopurine inhibit?
-Inhibits synthesis of purine nucleotides
What is the major ADR that occurs when patients take
6-mercaptopurine?
Myelosuppression