lecture 2- second messengers Flashcards
dose-response relationship
relationship between drug conc. at receptor site AND magnitude of response
i.e. lowering BP
what 3 things must researchers show when testing potential drug?
- if drug isnt there, there’s no effect
- adding more of drug will cause a change
- taking drug away means there is a return to original effect
ED50 (median effective dose)
dose at which 50 percent of the population or sample manifests a given effect
graded response vs quantal response
(arithmetic vs all or none)
effect of drug on an individual vs on a population
when does max response occur
when all receptors are occupied
the lower the ED50 the more the ____
potency of drug
why is efficacy more important than potency
because it reaches maximal effect of drug (emax)
affinity
measure of how tightly a drug binds to receptor
intrinsic actvity
measure of drug’s ability, once receptor bound, to generate an effect, activating a stimulus and producing a change in cellular activity
agonists have both affinity and intrinsic activity whilst antagonists ONLY have ____
affinity
define ALL-or-NONE response in terms of sedation given
sleep= ALL effect awake= NONE effect
TD50
median toxic dose
-50% pop manifests a toxic effect
LD50
median lethal dose
-dose which kills 50%
quantal dose response allows for what two effects
either therapeutic (td50) or toxic (td50,ld50)
therapeutic index -TI
ratio bw td or ld50 (undesirable effects) over ED50 (desired)
