Genetics Flashcards
what is avg efficacy of most drugs
50%
what is genetically enabled medicine (2)
- genetic tech to develop better drugs
2. predictive tests to get right dose of right drug to right person
who do we want to remove from drug therapy
non-responders and toxic responders
what is genetic variation
change in nucleotide sequences that leads to a change in phenotype
what is a rare vs. polymorphic variant
rare < 1% of pop
polymorphic < 1% (common)
how are SNPs useful (3)
- mapping markers
- correlate with disease predispostion
- correlate with drug toxicity and response
what are 3 potential types of metabolizers
- poor - little effect
- extensinve
- ultra rapid - show toxicity
does CYP2D6 do to codeine
makes morphine
does CYP2D6 do to tamoxifen
makes hydroxytamoxifen - more potent SERM
what happens to poor metabolizers of tamoxifen with breast cancer
death more common
what happens to warfarin with CYP2C9
if don’t have it get too much warfarin and bleeding risk
why is there only a 50% cure rate from ulcers due to omeprazole
low metbolizers do well , but get mix from super metabolizers
why is it important to know if people are good metabolizers or not
can change the dosing rate based on their ability to metabolize
what are potential pharmacodynamic changes that can be screened for
changes in receptor activity - eg. B2 receptors in the lung
what is herceptin
a $100000 monoclonal antibody directed against HER2 - an growth factor receptor on breast tissue - cancer
when is herceptin effective
only for those with HER2 overactivity (25%)
what is the challenge to polygentic disorders
can have many different factors affecting
6 areas of value for genetics
- drug target discovery
- drug discovery
- efficacy of drugs in development
- safety of drugs in dev.
- efficacy of approved drugs
- safety of approved drugs
how to find genes in population
GWAS - take 2 groups - 1 with disease and one without and look for SNPs differences in groups
how can genetics help clincial trials
stratification of the populations
3 ways stratification can help
- less overlap between groups
- higher statisitical power
- smaller sample size reqiured
when does testing make clinical sense (6)
- high predictive value
- interventions are possible
- high cost
- serious disease
- no alternative meds
- narrow therapeutic index of drug
