Week 2 Pharmacodynamics

Question 1

pharmacodynamics

Answer 1

The study of the biochemical and physiologic effects of drugs and the molecular mechanisms by which those effects are produced

Question 2

pharmacodynamics

Answer 2

The study of what drugs do to the body and how they do it

Question 3

Dose-Response Relationships

Answer 3

Relationship between the size of an administered dose and the intensity of the response produced

3 phases occur

Question 4

maximal efficacy

Answer 4

the largest effect that a durg can produce

Question 5

relative potency

Answer 5

The amount of drug that must be given to elicit an effect
Rarely an important characteristic of the drug
Can be important if a lack of potency forces inconveniently large doses
Implies nothing about maximal efficacy; refers to dosage needed to produce effects

Question 6

receptor

Answer 6

any functional macromolecule in a cell to which a drug binds to produce its effects (generally proteins)
Technically, receptors can include enzymes, ribosomes, and tubulin
The term receptor is generally reserved to refer to the body’s own receptors for hormones, neurotransmitters, and other regulatory molecules

Question 7

receptor binding

Answer 7

The binding of a drug to its receptor is usually reversible
Receptor activity is regulated by endogenous compounds
When a drug binds to a receptor, it will mimic or block the action of the endogenous regulatory molecules and increase or decrease the rate of physiologic activity normally controlled by that receptor

Question 8

drugs cannot

Answer 8

give cells new functions

Question 9

the more selective a drug is

Answer 9

the less side effects it will produce

Question 10

what makes selectivity possible

Answer 10

receptors

each type of receptor participates in the regulation of just a few processes

Question 11

body has receptors for each of the following

Answer 11

Neurotransmitters
Hormones
All other molecules in the body used to regulate physiologic processes

Question 12

simple occupancy theory

Answer 12

cannot explain different maximal efficacies of drugs

Question 13

affinity

Answer 13

strength of the attraction between drug and receptor

Question 14

intrinsic activity

Answer 14

ability of the drug to activate a receptor upon binding

Question 15

agonists

Answer 15

molecules that activate receptors

Question 16

endogenous regulators

Answer 16

agonists

Question 17

what has high affinity and intrinsic activity

Answer 17

agonists

Question 18

antagonists

Answer 18

produce their effects by preventing receptor activation by endogenous regulatory molecules and drugs

Question 19

what has affinity but no intrinsic activity

Answer 19

antagonists

Question 20

if there is no agonist present

Answer 20

antagonist will have no observable effect

Question 21

noncompetitive antagonists

Answer 21

Bind irreversibly to receptors
Reduce the maximal response that an agonist can elicit (fewer available receptors)
Impact not permanent (cells are constantly breaking down “old” receptors and synthesizing new ones)
Example: Omeprazole

Question 22

competitive agonists

Answer 22

Compete with agonists for receptor binding

Bind reversibly to receptors

Equal affinity: Receptor occupied by whichever agent is present in the highest concentration

Question 23

partial agonists

Answer 23

Compete with agonists for receptor binding

Bind reversibly to receptors

Equal affinity: Receptor occupied by whichever agent is present in the highest concentration

Question 24

drug responses that do not involve receptors

Answer 24

Simple physical or chemical interactions with other small molecules
Examples of receptorless drugs:
Antacids, antiseptics, saline laxatives, and chelating agents

Question 25

ED50

Answer 25

Dose that produces a response in 50% of the population

Question 26

therapeutic index

Answer 26

measure of drug’s safety

Question 27

TI index

Answer 27

drug’s LD50/ED50

Question 28

Larger therapeutic index

Answer 28

safer drug

Question 29

smaller TI

Answer 29

less safe drug