lecture 2- second messengers

Question 1

dose-response relationship

Answer 1

relationship between drug conc. at receptor site AND magnitude of response
i.e. lowering BP

Question 2

what 3 things must researchers show when testing potential drug?

Answer 2

• 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

Question 3

ED50 (median effective dose)

Answer 3

dose at which 50 percent of the population or sample manifests a given effect

Question 4

graded response vs quantal response

Answer 4

(arithmetic vs all or none)

effect of drug on an individual vs on a population

Question 5

when does max response occur

Answer 5

when all receptors are occupied

Question 6

the lower the ED50 the more the ____

Answer 6

potency of drug

Question 7

why is efficacy more important than potency

Answer 7

because it reaches maximal effect of drug (emax)

Question 8

affinity

Answer 8

measure of how tightly a drug binds to receptor

Question 9

intrinsic actvity

Answer 9

measure of drug’s ability, once receptor bound, to generate an effect, activating a stimulus and producing a change in cellular activity

Question 10

agonists have both affinity and intrinsic activity whilst antagonists ONLY have ____

Answer 10

affinity

Question 11

define ALL-or-NONE response in terms of sedation given

Answer 11

sleep= ALL effect
awake= NONE effect

Question 12

TD50

Answer 12

median toxic dose

-50% pop manifests a toxic effect

Question 13

LD50

Answer 13

median lethal dose

-dose which kills 50%

Question 14

quantal dose response allows for what two effects

Answer 14

either therapeutic (td50)
or toxic (td50,ld50)

Question 15

therapeutic index -TI

Answer 15

ratio bw td or ld50 (undesirable effects) over ED50 (desired)

Question 16

is a low or high TI better, why

Answer 16

high, because you cant overdose as easily

Question 17

NTI- narrow therapeutic index

Answer 17

lethal/median dose and ED50 have a less than 2 fold difference

Question 18

a drug with NTI has its dosage adjusted to ____

Answer 18

blood levels

Question 19

idiosyncratic response

Answer 19

genetic?
rare/abnl
-malaria=hemolysis in G6PD def pts

Question 20

hyper/hypo reactive

Answer 20

intensity of effect compared to normal; either diminished or increased

Question 21

tolerance

Answer 21

diminished response to drug with continued use; increase in dose in order to produce same effect

Question 22

tachyphylaxis

Answer 22

caused by reduced neurotransmitters to create drug effect

-loose efficacy of drug

Question 23

desnsitization

Answer 23

• receptors are still present, but unresponsive to prevent potential cell damage
• refractory period

Question 24

rebound phenomenon

Answer 24

when taking away medicine, the pt will go to previous response without drug