Pharmacogenetics

Question 1

Issues with drug therapy

Answer 1

Genetic differences may lead to variation between individuals and across populations
Response to drug therapy differently

Question 2

Pharmacogenetics

Answer 2

Polymorphisms

Most common: single nucleotide polymorphism - mutations, lead to amino acid substitutions

Question 3

Effects on metabolism of what drugs

Answer 3

Metoprolol - enhanced actions in poor metabolisers

Codeine - requires metabolic conversion and so reduced response in poor metabolisers (Chinese)

Question 4

Characteristic of dose of warfarin

Answer 4

Individual to patient

Question 5

Why is the dose of warfarin individual to patient

Answer 5

Genetic variation of metabolism of S-enantiomer
CYP2C9 polymorphism
VKORC1 differences - resistance to warfarin, pharmacodynamic

Question 6

Aspirin resistance

Answer 6

If resistant, more risk for CVD

Other anti-platelets don’t substitute for it

Question 7

Clopidogrel

Answer 7

Pharmacological activity influenced by its biotransformation
Prodrug
Influenced by genotype
PQN1 Q192R polymorphism, increased risk of thrombosis on stent

Question 8

What is a prodrug

Answer 8

Drug that requires conversion

Question 9

Cause of clopidogrel resistance

Answer 9

Polymorphisms of the P2Y 12 receptor may also contribute

Question 10

What causes altered pharmacological responses

Answer 10

Polymorphisms in drug target eg. Receptors

Eg. Beta 2 adrenoceptors in asthma and beta 1 adrenoceptors in CHF

Question 11

Ways the receptors are altered

Answer 11

Disease
Response to beta 2 agonists
Desensitisation