Pharmacology Summary

Question 1

Pharmacodynamics meaning

Answer 1

What a drug does to the body

Question 2

Pharmacokinetics meaning

Answer 2

What the body does to a drug

Question 3

What are receptors?

Answer 3

Class of cellular macromolecules

Question 4

What is an agonist?

Answer 4

Drug that binds to a receptor

Question 5

What is affinity?

Answer 5

Strength of association between ligand and receptor

Question 6

What is efficacy?

Answer 6

Ability of an agonist to evoke a cellular response

Question 7

Do agonists have affinity and efficacy?

Answer 7

Agonists have affinity and efficacy

Question 8

What is an antagonist?

Answer 8

Drug that blocks the actions of an agonist

Question 9

Do antagonist possess affinity and efficacy?

Answer 9

Possess affinity but lacks efficacy

Question 10

What is competitive antagonism?

Answer 10

Binding of agonist and antagonist occur at the same site

Question 11

Does competitive antagonism affect maximal response?

Answer 11

No

Question 12

How is competitive antagonism overcame?

Answer 12

Increasing concentration of agonist

Question 13

What is non-competitive antagonism?

Answer 13

Agonist binds at one site and antagonist binds at a separate site

Question 14

During non-competitive antagonism what does antagonist binding cause?

Answer 14

Activation cannot occur when is bound

Question 15

Does non-competitive antagonism effect maximal response?

Answer 15

It decreases maximal response

Question 16

Does a concentration increase of agonist effect maximal response?

Answer 16

No

Question 17

What is absorption?

Answer 17

Process by which a drug enters the body from its site of administration

Question 18

What is distribution?

Answer 18

Process by which drug leaves circulation and enters the tissues perfused with blood

Question 19

What is metabolism?

Answer 19

Process by which tissue enzymes catalyse chemical conversion of a drug to a more polar form that is more readily excreted from the body

Question 20

What is excretion?

Answer 20

Process that removes the drug from the body

Question 21

What factors control drug absorption?

Answer 21

Solubility
Chemical stability
Lipid to water partition coefficient
Degree of inonisation

Question 22

How does solubility affect drug absorption?

Answer 22

Drug must be able to dissolve

Question 23

How does chemical stability affect drug absorption?

Answer 23

Some drug may be dissolved by acid

Question 24

How does lipid to water partition coefficient affect drug absorption?

Answer 24

Rate of diffusion of drug increases with lipid solubility

Question 25

What affects the degree of ionisation?

Answer 25

pKa of the drug and local pH

Question 26

What is the Henderson-Hasselbalch equation?

Answer 26

pH = pKa + log([A⁻]/[HA])

Question 27

What is pKa?

Answer 27

pH in which 50% of drug is ionised and 50% is unionised

Question 28

If Ka is large?

Answer 28

Strong acid

Question 29

What is oral availability?

Answer 29

Fraction of drug that reaches systemic circulation after oral ingestion

Question 30

What is systemic availability?

Answer 30

Fraction of drug that reaches systemic circulation after absorption

Question 31

What are the routes of administration?

Answer 31

Enteral Parenteral

Question 32

How are enteral drugs absorbed?

Answer 32

Via the gut

Question 33

How are Parenteral drugs absorbed?

Answer 33

Not via the gut

Question 34

Examples of enteral methods of administration

Answer 34

Oral Sublingual Rectal

Question 35

Examples of parenteral methods of administration

Answer 35

Intravenous Intramuscular and subcutaneous Inhalation Topical

Question 36

What is a feature of drugs within systemic circulation?

Answer 36

Can be distributed to one or more body fluid compartment

Question 37

Are drugs evenly distributed within the body?

Answer 37

No

Question 38

What is volume distribution?

Answer 38

Apparent volume in which a drug is dissolved

Question 39

What is the volume distribution equation for IV?

Answer 39

Vd = dose/plasma concentration

Question 40

What is MEC?

Answer 40

Minimum effective concentration

Question 41

What is MTC?

Answer 41

Maximum tolerated concentration

Question 42

Formula for therapeutic ratio

Answer 42

Therapeutic Ratio = MTC/MEC

Question 43

What does a high therapeutic ratio indicate?

Answer 43

That drug is safe

Question 44

What is the rate of elimination directly proportional to?

Answer 44

Drug concentration

Question 45

How is plasma concentration effected by elimination?

Answer 45

Falls exponentially

Question 46

Half life equation

Answer 46

T1/2 = 0.693 * Vd / CL

Question 47

What is clearance?

Answer 47

The volume of plasma cleared of drug in unit of time

Question 48

Equation for rate of clearance

Answer 48

Rate of elimination = clearance * plasma concentration

Question 49

After how many half lives is steady state reached?

Answer 49

5

Question 50

When does steady state exist?

Answer 50

Rate of drug administration = rate of drug elimination

Question 51

Equation to determine Cpss (Steady state concentration)

Answer 51

Cpss = maintainance does rate / clearance

Question 52

During oral dosing how does the plasma concentration behave?

Answer 52

Fluctuates about an average steady state value

Question 53

What is Vd?

Answer 53

Volume of distribution

Question 54

What is volume of distribution?

Answer 54

Volume into which a drug appears to be distributed with a concentration equal to that of plasma

Question 55

What is loading dose?

Answer 55

Use of an initial higher dose of drug before stepping down to lower maintenance dose

Question 56

Why is loading dose used?

Answer 56

Decreases time to stead state in drugs with a long half life

Question 57

What is half life?

Answer 57

Time for the concentration of drug plasma to halve