Lecture 53 - pharmacodynamics

Question 1

How do drugs produce effects in the body?
*big concept

Answer 1

biochemically and physiologically

Question 2

summarize 3 ways a drug produces changes

Answer 2

1. drug binds to a target molecule
2. change in physical property
3. chemical or metabolic change

Question 3

T/F: drugs do not create new cell effects/actions

Answer 3

TRUE

Question 4

define ligand

Answer 4

something that binds a receptor

Question 5

where are drug receptors located

Answer 5

on or within cell surface/cytoplasm

Question 6

Describe ionotropic receptors

Answer 6

ion channel for Na+, K+, Cl-
fast-acting
voltage- or ligand-gated

Question 7

describe metabotropic receptors

Answer 7

no pore/channel
secondary messengers (G-coupled)
slow

Question 8

what are the 4 major receptor types

Answer 8

1. ion channel
2. G-protein coupled receptors
3. enzyme-linked
4. intracellular

Question 9

What receptors are the target of over 50% of drugs

Answer 9

G-protein coupled receptors

Question 10

describe Gs

Answer 10

• activate adenylyl cyclase
• increase cAMP
• generate response

Question 11

describe Gi

Answer 11

• decrease AC and cAMP
• inhibit ion channels

Question 12

describe Gq

Answer 12

• activate PLC

Question 13

describe enzyme-linked receptors

Answer 13

• extracellular binding sites
• receptor autophosphorylates
• EX: insulin. growth factors

Question 14

summarize how intracellular receptors work in 5 steps

Answer 14

1. steroid hormone diffuses through plasma membrane and binds receptor
2. receptor-hormone complex enters nucleus
3. receptor-hormone complex binds specific DNA region
4. binding initiates transcription of bound gene
5. mRNA directs protein synthesis

Question 15

define drug activity (intrinsic efficacy)

Answer 15

ability of a drug to have a response

Question 16

define drug affinity

Answer 16

force of attraction between drug and receptor

Question 17

define drug selectivity

Answer 17

drug’s ability to affect a particular receptor population in preference to others

Question 18

define agonist

Answer 18

binds to a receptor and causes a response

“mimetic”

Question 19

define partial agonist

Answer 19

binds and activates the receptor

results in partial response

Question 20

define antagonist

Answer 20

binds to receptor and does not cause a response

“blocker”

Question 21

what is a competitive antagonist

Answer 21

It looks like the drug and binds at the same site

Question 22

what is a non-competitive antagonist

Answer 22

binds somewhere else and changes conformation so agonist cannot bind

Question 23

why is is preferred to take a highly selective drug

Answer 23

binding to only one receptor decreases chance of side effects

Question 24

define potency

Answer 24

amount of drug needed to produce a response

Question 25

dose-response relationship

Answer 25

the more drug you give, the more response you get

Question 26

T/F: a high-potency drug will have the desired response when greater concentrations are achieved

Answer 26

FALSE

Question 27

what is the therapeutic index?

Answer 27

the relative safety of a drug