Week 12 - Pharmacology: Intro to Pharmacodynamics

Question 1

What is a drug

Answer 1

A chemical substance of known structure, other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect

Question 2

What are examples of drugs

Answer 2

Penicillin, Aspirin, Caffeine, St John’s wort, Flavonoids (green tea)

Question 3

What is pharmacodynamics

Answer 3

the study of what the drugs does to the body

Question 4

What are drug targets

Answer 4

Any binding site that interacts with a drug
Drug molecules have to interact with the target to have an effect

Question 5

What do dose response curves show the relationship between

Answer 5

drug concentration and pharmacological response. (how much drug is required to produce the desired effect)

Question 6

What is the threshold in a dose response curve

Answer 6

the concentration where effects start to occur

Question 7

What is EC50 in a dose response curve

Answer 7

the concentration where half of the maximum effect occurs

Question 8

What is the maximum effect on a dose response curve

Answer 8

the concentration where the full response occurs

Question 9

What is efficacy

Answer 9

• the maximum effect that can be produced once binding has occurred. The higher
• The higher the maximum effect of the drug the higher the efficacy of the drug

Question 10

What is potency

Answer 10

• The amount of drug needed to provide clinical effect
• If a small amount is required then the drug has a high potency (ideal)
• If a large amount is required then the drug has low potency
• Potency is influenced by both efficacy and affinity

Question 11

What is affinity

Answer 11

• The amount of binding to receptor the drug does
• High affinity means that the drug is binding to more receptors at lower concentrations
• Low affinity means that the drug is binding less and or dissociates more easily from receptors

Question 12

What type of drugs are receptor binding

Answer 12

• agonist
• antagonist

Question 13

What is an agonist

Answer 13

Agonist mimic the effect of the ligand (such as neurotransmitters, hormones or other signaling molecules) by binding to the same receptor and producing a similar effect.

It enhances the receptor effect

These can have high affinity and high efficacy

E.g. Type 2 diabetes drug (GLP-1) which mimics insulin receptor to lower blood sugar levels

Question 14

What are the 2 types of agonist drugs

Answer 14

• full agonist
• partial

Question 15

What is a full agonist

Answer 15

agonist drug which can achieve maximal response (high efficacy)

Question 16

What is a partial agonist

Answer 16

agonist drug which produces a submaximal response even with high concentration, low efficacy (will never achieve maximum effect)

Question 17

What is an antagonist

Answer 17

Antagonist bind to specific receptors in the body without activating them, thereby blocking or inhibiting the action of the substrate that would normally activate the receptor.

e.g. Naloxone

Question 18

What is a reversible antagonist

Answer 18

Doesn’t strongly bond to the receptor and can be overridden by a high concentration of agonist

Question 19

What is a irreversible antagonist

Answer 19

Forms strong bond to the receptor and cannot be disrupted by an agonist

Question 20

What type of drugs are enzyme binding

Answer 20

inhibitors

Question 21

What type of drug are carrier proteins/molecules

Answer 21

Drugs which are carrier proteins/molecules act in a similar manner to enzymes and acts as an inhibitor.
E.g. GLUT-4 which lets glucose be taken up by cells or NA+/K+ pump which helps resets the charge of a cell in the production of active potential

Question 22

What is Selectivity

Answer 22

The ability of a drug to interact preferentially with one type of receptor or target over others. A drug can be specific and only bind to certain or singular receptors, or a drug can be non-specific and bind to several types of receptors.

Question 23

What is Specificity

Answer 23

Refers to the degree to which a drug interacts directly with its intended target and does not interact with other molecule before binding to the receptor

Question 24

Explain how beta blockers showcase side effects of drugs

Answer 24

The B-adrenergic receptor increases the heart rate and has 2 subunits - B1 and B2

Some selective drugs only interact to subunit B1 e.g. dobutamine

Other non-selective drugs interact to both B1 and B2 subunits e.g. propranolol

The issue is that B2 receptors can also be found in other locations other than the hear such as the lungs, blood vessels, GI tract, bladder, uterus , liver. Hence in non-selective drugs effects can be seen on these organs, resulting in side effects such as breathing problems, constipation nausea, dizziness.

Question 25

What are common local anesthetics

Answer 25

lidocaine and antiacne

Question 26

What type of drug is local anesthetic

Answer 26

antagonic

Question 27

How does local anesthetics work

Answer 27

• Local anesthetic works by blocking the generation and propagation of action potentials in neurons, by blocking the flow of Na+
• They bind to ion channels and block the flow of Na+
• By blocking sodium channels it prevents the transmission of nerve impulses along sensory nerves, and hence the sensation of pain is temporarily abolished
• They are unionized molecules

Question 28

Local anesthetics targets what

Answer 28

voltage gated sodium channels - antagonist

Question 29

Does local anesthetics work intracellularly or extracellularly

Answer 29

Intracellular