Lecture 1 - personalised medicine Flashcards
What does personalised medicine aim to achieve
Reduced trial and error prescribing Avoid adverse reactions Increase patient compliance Reveal additional uses Control the cost of healthcare.
What are the 7 main causes for variability in drug responses
Age Ethnicity Genetics/genomics Immunological factors Concomitant disease Pregnancy Drug interactions
How does age interfere with drug action
In new borns the organs are not well developed. E.g the GFR in newborns is around 20% of adults, therefore the half life of a drug is much longer.
What drug has a half life of 40 hours in adults, 200 hours in newborns and 80 hours in the elderly
Digoxin
How do SNPs effect drug action
SNPs can effect the way that a drug is metabolised.
What is inherited thrombophilia
An SNP in factor V, part of the clotting cascade. People with the mutation are prone to deep vein thrombosis and increased tendency to form clots.
Concomitant diseases effecting which organ will have an effect on drug action
Kidney and liver as they are the main sites for metabolising drugs.
What is the result of drugs that cause gastric stasis
Slow the metabolism of a given drug.
What is a disease that renders statins ineffective
Familial hypercholesterolemia. Lack of function of LDLR receptors.
What do diuretics do and what does this predispose a patient to
Lower plasma potassium and predisposes a patient to digoxin toxicity
What is the action of Siladenafil
Used in pulmonary artery hypertension, its a vasodilator that potentiates organic nitrates. In combination with other drugs it can cause severe hypotension.
How does warfarin metabolism differ between individuals
The CIP2C9 gene encodes the enzyme which metabolises warfarin. SNPs of the gene *2 and *3 metabolise the drug slower than WT so the conc of the drug has to be increased.
What is VKORC
An apoxide enzyme which encodes the drug target of warfarin which also has a number of polymorphisms
What polymorphisms are present for VKORC and what does this mean
GG, GA and AA. People with the AA variant are more sensitive to warfarin and require a lower dose. Both this and the CYP2C9 gene info is required to decide the dosage for a patient on warfarin.
