Pharmacology

Question 1

Define pharmacokinetics

Answer 1

What the body does to the drug

Question 2

Define pharmacodynamics

Answer 2

What the drug does to the body

Question 3

What are the 4 drug targets?

Answer 3

Receptors, Enzymes, Transporters and Ion channels

Question 4

What are the 4 types of receptor?

Answer 4

1. Ligand-gated ion channels
2. G protein coupled receptors
3. Kinase linked receptors
4. Cytosolic/nuclear receptors

Question 5

Give some examples of when an imbalance of chemicals leads to pathology?

Answer 5

Increased histamine leading to allergy

Reduced dopamine leading to Parkinson’s

Question 6

Give some examples of when an imbalance of receptors leads to pathology?

Answer 6

Loss of ACh receptors in myasthenia gravis

Increased c-kit receptor in mastocytosis

Question 7

Define agonist

Answer 7

A compound that binds to a receptor and activates it

Question 8

Define antagonist

Answer 8

A compound that reduces the effect of an agonist

Question 9

Define potency

Answer 9

A measure of how well a drug works

Question 10

What is EC50?

Answer 10

The concentration that gives half the maximal response

Question 11

How do you calculate intrinsic activity?

Answer 11

Emax of partial agonist/Emas of full agonist

Question 12

What are the receptor related factors that govern drug action?

Answer 12

Affinity and Efficacy

Question 13

What are the tissue related factors that govern drug action?

Answer 13

Receptor number and signal amplification

Question 14

Define efficacy

Answer 14

Efficacy describes how well a ligand activates a receptor

Question 15

What is the difference between agonists and antagonists in terms of efficacy and affinity?

Answer 15

Agonists- affinity and efficacy

Antagonists- affinity but zero efficacy

Question 16

Define tolerance and describe how it arises

Answer 16

Reduction in drug effect over time caused by continuous, repeated, high concentrations

Question 17

What are the 3 actions of NSAIDs?

Answer 17

Analgesic, Anti-pyretic and Anti-inflammatory

Question 18

What do NSAIDs inhibit?

Answer 18

cyclooxygenase (COX)

Question 19

What does COX do?

Answer 19

COX generates Prostaglandin H2 which is then acted on by specific synthases to generate prostanoids

Question 20

What two isoforms does COX exist as?

Answer 20

COX-1: constitutive (normal physiology)

COX-2: induced (inflammation)

Question 21

Outline the mechanism of ACE inhibition

Answer 21

Captopril mimics dipeptide (His Leu) and binds at the active site of ACE, preventing angiotensin 1 binding

Question 22

What is the action of beta-lactam antibiotics?

Answer 22

Inhibit cell wall biosynthesis

Question 23

Give the sites of actions of the two diuretics, furosemide and thiazides

Answer 23

Furosemide- ascending loop

Thiazides- distal tube

Question 24

What is the mechanism of action of diuretics?

Answer 24

Reduced reabsorption of salt from filtrate resulting in increased excretion of ions
Water reabsorption inhibited resulting in increased excretion of water

Question 25

What is the action of neuronal uptake inhibitors?

Answer 25

They increase the neurotransmitter concentration at the cleft

Question 26

Give some examples of neuronal uptake inhibitors

Answer 26

Fluoxetine- selective serotonin reuptake inhibitor (SSRI)

Imipramine- tricyclic anti-depressant (mostly NAd, 5HT)

Question 27

What are the two types of calcium channel blocker and give examples

Answer 27

Dihydropyridines- amlodipine

Non-hydropyridines- verapamil, diltiazem