Dose response curves

Question 1

what is receptor based model

Answer 1

binding of drug to targets can result in response that can be modelled graphically

Question 2

what is law of mass action

Answer 2

rate of reaction is proportional to [c] of reactants

Question 3

what assumption of law of mass action

Answer 3

ligand binds in a reversible manner

Question 4

what is fractional occupancy of receptor formula

Answer 4

[bound receptors] / [total receptors]

Question 5

** key response formula

Answer 5

response = [drug]*[max response] / dissoctiaion constant + [drug]

Question 6

what is ED50 on dose response curve

Answer 6

dose that give 50% of max response

Question 7

what is efficacy

Answer 7

max effect a drug can have - ideal world

Question 8

what is potency

Answer 8

reflects the dose/conc. required for specific effect

Question 9

what values can be used to compare potency

Answer 9

ED50

Question 10

what does higher potency mean

Answer 10

more effect with less dose

Question 11

rule of thumb regarding doses

Answer 11

generally want to give the smallest dose possible

Question 12

3 types of agonists

Answer 12

1. full - prefers active state and gives full effect
2. partial - has less efficacy when bound - never full effect
3. inverse - cuases action, but reverses state

Question 13

what is competitive antagonist

Answer 13

competes for binding sites and shuts down agonist action

Question 14

how to overcome comp. antag

Answer 14

give more

Question 15

2 types of non-competitive antagonists

Answer 15

1. irreversible - binds and never lets go - can’t overcome

2. allosteric - binds to different site, but changes the affinity of binding site to agonist

Question 16

what will happen if give more agonst with 2 types of anstagonsist

Answer 16

competitive - can eventually overcome

irrevesible - will never get to full efficicacy

Question 17

2 types of non-receptor related antagonsism

Answer 17

1. chemical - change bonding

2. physiological -

Question 18

what is desensitization

Answer 18

agonist produces lesser effect as repeated exposure

Question 19

what is tachyphylaxis

Answer 19

rapid decrease in effect after repeated same dose

Question 20

2 types of D-R curve

Answer 20

1. graded - y axis is % of effect

2. quantal - y axis is % of pop responding

Question 21

what is therapeutic index

Answer 21

LD50/ED50 - dose that is lethal in 50% of pop/ dose that is effective in 50% of pop

Question 22

what is certain safety factor

Answer 22

LD1/ED99

Question 23

what is CSF factor good for

Answer 23

comparing relative safety of drugs