Chapter 5 - Pharmacodynamics Flashcards Preview

Nu 578: Ch 4-19 Exam 1 > Chapter 5 - Pharmacodynamics > Flashcards

Flashcards in Chapter 5 - Pharmacodynamics Deck (24):
1

Pharmacodynamics

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

2

Dose-response relationship

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

determines the minimum amount of drug needed to elicit a response, the maximum response a drug can elicit, and how much to increase the dosage to produce the desired increase in response.

3

Dose-response curves reveal two characteristic properties of drugs:

maximal efficacy and relative potency.

4

Maximal efficacy

the largest effect that a drug can produce.

5

Maximal efficacy is indicated by the ____ of the dose-response curve

height

6

What are the four primary families of receptors?

1. cell membrane–embedded enzymes

2. ligand-gated ion channels,

3. G protein–coupled receptor systems,

4. transcription factors

7

Where is the ligand- binding domain located in Cell membrane- embedded enzymes?

cell surface, and the enzyme's catalytic site is inside

8

Cell Membrane–Embedded Enzymes

Binding of an endogenous regulatory molecule or agonist drug activates the enzyme, thereby increasing its catalytic activity ex insulin

9

Ligand-Gated Ion Channels

The function of these receptors is to regulate flow of ions into and out of cells. GABA AND ACETYLCHOLINE

Like membrane-embedded enzymes, ligand-gated ion channels span the cell membrane

10

G Protein–Coupled Receptor Systems

G protein–coupled receptor systems have three components: the receptor itself, G protein (so named because it binds guanosine triphosphate [GTP]), and an effector (typically an ion channel or an enzyme).

11

Transcription factors

differ from other receptors in two ways: (1) transcription factors are found within the cell rather than on the surface, and (2) responses to activation of these receptors are delayed

Ex - Steriods and thyroid hormones

12

What is the function of transcription factors?

regulate protein synthesis

13

affinity

refers to the strength of the attraction between a drug and its receptor
** Drugs with high affinity are strongly attracted to their receptors **

14

intrinsic activity

the ability of a drug to activate a receptor upon binding

15

The intrinsic activity of a drug is reflected in its ________

maximal efficacy

16

an antagonist is a drug with affinity for a receptor but with no ______

intrinsic activity

17

A partial agonist is an agonist that has only moderate

intrinsic activity ex- Pentazocine(Talwin) a narcotic

18

The therapeutic index is defined as ______

the ratio of a drug's LD50 to its ED50.

19

The therapeutic index is a measure of

a drug's safety.

20

The ED50 is defined as ____

the dose that is required to produce a defined therapeutic response in 50% of the population

21

What are some examples of drugs that do not act of receptors?

antacids, antiseptics, saline laxatives, and chelating agents.

22

Partial agonists are interesting in that they can act as

antagonists as well as agonists

23

Competitive antagonists bind _____ to receptors

reversibily

24

Noncompetitive antagonists bind _______ to receptors.

irreversibily