Principles of Pharmacology

Question 1

What makes a drug a ‘medicine’?

Answer 1

The intention of being given with therapeutic effect

Question 2

What is a drug?

Answer 2

A chemical compound that produces biological effects

Question 3

What is the term for drug substances that are already present in the body? Give two examples.

Answer 3

Endogenous

1. Insulin
2. Adrenaline

Question 4

What is the 4-step pathway for discussing and studying the pharmacological effects of a drug?

Answer 4

1. Pharmacodynamics
2. Pharmacokinetics
3. Clinical Uses
4. Adverse effects and Contraindications

Question 5

Define Pharmacodynamics

Answer 5

The drug’s mechanism of action upon the body

Question 6

Define Pharmacokinetics. Include an explation of the ADME acronym

Answer 6

The body’s mechanism of action upon the drug.
Absorption-Distribution-Metabolism-Excretion.

Question 7

What is the difference between Adverse Effects and Contraindications?

Answer 7

Adverse Effects are the non-theraputic, unwanted physiological effects of the drug.

Contraindications are the physiological/social/psychological factors in the patient that act as reasons NOT to prescribe the drug

Question 8

What are the primary and secondary pharmacodynamic effects of Aspirin/NSAIDs?

Answer 8

1. Analgesic
2. 2 Anti-pyretic (anti-fever)
3. 3 Anti-inflammatory
4. Anti-platelet aggregation

Question 9

Describe the pharmacodynamic mechanism of Aspirin

Answer 9

1. Inhibits Cyclooxygenase (COX)
2. COX catalyses Arachidonic Acid into Prostaglandings and Thromboxanes

Question 10

Describe the 4 main physiological roles of Prostaglandins

Answer 10

1. Sensitise pain nerve endings
2. Dilates blood vessels (redness/inflammatory)
3. Increases blood vessel permeability (swelling of Int. fluid comp)
4. Induces fever

Question 11

Describe the main physiological role of Thromboxanes

Answer 11

Induces increased platelet-aggregation

Question 12

Drugs often act at ________ which are expressed only in selective tissues, and have the correct chemical structure to bind the drug.

Answer 12

Receptor Sites

Question 13

Name three key effects of drug action as perpetuated by the ‘receptor site’ system.

Answer 13

Tissue Selectivity

Chemical Selectivity

Action Amplification (even at v. Small concentrations)

Question 14

What name is given to the type of drug in which the drug binds to a receptor but DOES NOT induce a biological effect?

Answer 14

Antagonist

Question 15

Define an ‘Agonist’ drug.

Answer 15

A drug which binds to a receptor to produce a biological cellular response

Question 16

Draw a diagram to show the steps and relationship between drug ‘affinity’ and ‘efficacy’ in both agonists and antagonists.

Answer 16

Question 17

Out of agonists and antagonists, which is the only one which can have a measured ‘efficacy’? And why?

Answer 17

Agonists. Because only agonists produced a direct biological response, whereas antagonists merely block receptor sites to inhibit the effect of endogenous hormones/enzymes

Question 18

Define KA in the context of drug affinity

Answer 18

KA is known as the Equilibrium Constant. Specifically, it outlines the point at which exactly 50% of the receptor sites have been filled.

Question 19

Draw a diagram to outline drug affinity. What type of pattern is formed by the typical data?

Answer 19

Question 20

Define the EC50 of a drug. What quality does it measure?

Answer 20

The concentration at which 50% of the maximal biological response is achieved. Also designates the drug’s potency.

Question 21

Draw a diagram to show why KA and EC50 are not equal, and explain why?

Answer 21

Question 22

What do we call the ‘strength’ of a drug, as determined by a combination of its affinity and efficacy?

Answer 22

Potency

Question 23

Define ‘ligand’

Answer 23

Defined as any molecule or atom that irreversibly binds to a receptor

Question 24

What are ‘Partial Agonists’?

Answer 24

Partial agonists are ligands that bind to the agonist recognition site but trigger a response that is lower than that of a full agonist at the receptor

Question 25

What type of antagonism involves antagonists competing with agonists for the same binding site?

Answer 25

Competitive antagonism

Question 26

If KAnt \< KA, which will occupy more receptor sites at equal concentrations?

Answer 26

Antagonist

Question 27

Draw a diagram outlining ‘Surmountable’ antagonism. Why is there a parallel shift to the right in the present of antagonists?

Answer 27

Because the concentration of the agonists must be increased in a linear fashion to induce the same maximal biological response

Question 28

Draw a diagram outlining ‘Insurmountable’ antagonism. Why is there a an antagonist-sensitive component? What are the differences between non-competitive and irreversible antagonism?

Answer 28

Question 29

Name the four types of receptors, and give an example of an endogenous or given drug that acts there

Answer 29

Question 30

Give an an overview of tissue selectivity

Answer 30

Question 31

Give an overview of Chemical Selectivity

Answer 31

Question 32

Give an overview of Intercellular communication

Answer 32

Question 33

Give an overview of amplification

Answer 33

Question 34

Broadly speaking, what are the four categories of receptor families?

Answer 34

Question 35

Give three examples of intracellular messengers

Answer 35

cAMP (Cyclic AMP) DAG (Diacylglycerol) IP3 (Inositol 1,4,5-triphosphate)

Question 36

Give an overview of Ligand gated receptor/channel complexes Include an: Example Structure Mechanism Speed

Answer 36

Question 37

Give an overview of G-coupled protein receptors. Include an: Example Structure Mechanism Speed

Answer 37

Question 38

Describe the process of intracellular communication initiated via G-protein coupled receptors

Answer 38

Question 39

Draw the basic pathway function of G*a*S/G*a*I vs G*a*Q receptors and how they instigate intracellular communication

Answer 39

Question 40

Give a diagrammatic outline of how Intracellular receptors work

Answer 40

Question 41

Give an outline of how tyrosine kinase receptors work

Answer 41