Pharmacodynamics

Question 1

What is pharmacology?

Answer 1

The science of interactions of chemical compounds with biological systems

Question 2

What does pharmacodynamics refer to?

Answer 2

Drug effects on the body

Question 3

What does pharmakokinetics refer to?

Answer 3

Body’s effects on the drug

Question 4

What does ADME refer to?

Answer 4

Absorption, Distribution, Metabolism, Excretion

Question 5

Purpose of drug therapy?

Answer 5

To produce a characteristic effect by achieving adequate concentrations at its site of action while minimizing undesired effects

Question 6

What is a side effect?

Answer 6

An unwanted or bothersome effect of a drug usually related to the main effect.

Question 7

What is a toxic effect?

Answer 7

A harmful or adverse effect of a drug usually not directly related to the main effect

Question 8

What is a placebo?

Answer 8

A formulation that is identical in appearance to the real product but without the active drug

Question 9

Drugs can only modify ______ fxn.

Answer 9

Cullular

Question 10

Name for the drug action you want

Answer 10

Therapeutic effect

Question 11

Two examples of drug actions extracellularly.

Answer 11

Neutralization of excessive gastric acid by antacids

Heparin in preventing blood coagulation

Question 12

Two examples of drug interactions intracellularly

Answer 12

Drugs to treat infections
Drugs used for cancer chemotherapy
Hormones such as estrogen

Question 13

_____ largely determine the quantitive relationship between dose/conc. of drug and the pharmacologic effects

Answer 13

Receptors

Question 14

Similarities and differences between agonists and antagonists.

Answer 14

Similarities – Bind to a specific receptor

Differences - agonists stimulate receptor action, antagonists do not

Question 15

What is observed at saturable levels of drugs

Answer 15

Concentrations at which no further increase in response can be achieved with increasing concentration

Question 16

In the law of mass action, what is the association rate constant a measure of?

Answer 16

Potency

Question 17

What does the relationship between DR –> Effect measure

Answer 17

Efficacy

Question 18

Rate of association =

Answer 18

(D)(R)(k1)

Question 19

Rate of dissociation =

Answer 19

(DR) (k-1)

Question 20

At equilibrium, Rate of Association=

Answer 20

Rate of dissociation

Question 21

Dissociation Constant (Kd) =

Answer 21

(k-1)/(k1) = (D)(r)/(DR)

Question 22

The dissociation constant is _______ to the affinity

Answer 22

Inversely proportional

Question 23

Equation for Receptor Occupancy =

Answer 23

[(Drug Concentration)(Max # of Receptors)]/(Drug Concentration) + (Kd)

Question 24

What does Kd refer to?

Answer 24

The drug concentration at which half of the receptors are occupied

Question 25

Three assumptions of the law of mass action

Answer 25

1. Binding is reversible
2. D and R only exist as free and bound
3. All receptor sites have equal affinity and are independent

Question 26

What is potency?

Answer 26

The dose of a drug required to produce a particular effect of given intensity

Question 27

What is affinity?

Answer 27

The ability of a drug to interact with the receptor

Question 28

Relationship between affinity and potency?

Answer 28

Affinity is a determinant of potency

Question 29

What is efficacy?

Answer 29

The biological response resulting from the drug-receptor reaction

Question 30

A strong agonist has a ____ affinity and a _____ efficacy

Answer 30

high, high

Question 31

What may limit maximal efficacy?

Answer 31

Toxicity

Question 32

Who is more important as a drug – efficacy or potency?

Answer 32

Efficacy

Question 33

What changes in effect are seen when a partial agonist is used?

Answer 33

Reduced response even at full receptor occupancy.

May competitively inhibit the response to a full agonist

Question 34

Three major types of receptor antagonists?

Answer 34

Competitive
Mixed
Irreversible

Question 35

What occurs in competitive antagonism?

Answer 35

Reversible/Equilibrium Competitive antagonism

Question 36

Effect of a competitive antagonist on the log dose-response curve?

Answer 36

Shift to the right

Question 37

What does receptor reserve refer to?

Answer 37

When the maximal response can be elicited by an agonst at a concentration that does not result in 100% occupancy of available receptors

Question 38

What is a noncompetitive agonist?

Answer 38

An antagonist that produces its effect at a site of the receptor other than the site used by the agonist

Question 39

Log dose-response curve response to a non-competitive antagonist?

Answer 39

Curve shifts to the rights and the slope/maximal response are progressively decreased

Question 40

Log dose-resonse curve response to an irreversible antagonist?

Answer 40

Initially, right shift (like competitive)

As concentration increases, maximal response is diminished (like in noncompetitive inhibition)

Question 41

Molecularly, how does irreversible antagonism tend to work?

Answer 41

Covalent reaction between the antagonist and the same site as athe agonist. The antagonist is difficult to remove and inhibition can persist even after removal.

Question 42

Effect of positive allosteric activators?

Answer 42

Increased potency and/or efficacy

Question 43

Define functional antagonism. give an example

Answer 43

Twi drugs influence a physiological system in opposite directions. No direct chemical interaction.

Acetylcholine decreasing BP while epinephrine increases it

Question 44

Define chemical antagonism. Give an example.

Answer 44

A chemical reaction occurs between an agonist and an antagonist to form an inactive product.

Calcium containing antacids and tetracycline ABs
Cyanide and sodium nitrite