Pharmacology

Question 1

Drug Targets

Answer 1

1. Receptors
2. Enzymes
3. Transporters
4. Ion channels

Question 2

Affinity and efficacy

Answer 2

Affinity = how well ligand binds to receptor
(antagonists + agonists)
Efficacy = how well a ligand activates receptor
(agonists)

Question 3

Tolerance

Answer 3

Reduction in drug effect over time

Question 4

Desensitisation of receptors

Answer 4

1. Uncoupled - can’t interact with G protein
2. Internalised - in vesicle
3. Degradation

Question 5

B blockers - contraindication

Answer 5

Asthma

Bronchoconstriction

Question 6

Compartments of water

Answer 6

1. Intracellular 2/3
2. Extracellular 1/3
   - Plasma (20% of ECF)

Question 7

Movement between compartments

Answer 7

1. Simple Diffusion
2. Facilitated Diffusion
3. Non-ionic diffusion
4. Active transport

Question 8

Stages of Pharmacokinetics

Answer 8

1. Absorption
2. Distribution
3. Metabolism
4. Excretion

Question 9

Bioavailability

Answer 9

Amount of drug taken up as proportion of amount administered

Question 10

Reporting ADRs

Answer 10

1. MHRA Yellow Card scheme
   - All suspected for new medicines
   - All in children
   - All serious reactions

Question 11

Naloxone

Answer 11

1. Competitive receptor antagonist of morphine

2. Correct morphine overdose - resp depression

Question 12

Therapeutic index

Answer 12

Dosage difference between therapeutic effect and toxic affect
Simvistatin

Question 13

Types of ADRs

Answer 13

ABCDE 
A - Augmented (extension of clinical effect)
B - Bizarre (unexpected
C - Chronic (LT therapy)
D - Delayed (many years)
E - End of use (withdrawal)

Question 14

Adherence

Answer 14

Extent to which patient’s actions match agreed recommendations

Question 15

Anaphylaxis

Answer 15

1. Type 1 hypersensitivity
2. IgE mediated
3. Prior exposure to drug
4. Mast cell degranulation
   - Histamine
   - Thromboxane / prostaglandins
   - TNF
5. Rash

Question 16

Half life

Answer 16

Time taken for plasma drug concentration to fall to half of its original value

Question 17

Adreno-receptors

Answer 17

A1 = vasconstricion, pupil dilation + bladder contraction
A2 = presynaptic inhibition of neuroadrenaline --> reduce insulin release
B1 = increase HR + force + electrical conduction, more renin + increased BP
B2 = bronchodilation, vasodilation + less GI motility
B3 = more lipolysis, relax bladder

Question 18

Type 2 diabetes - Treatment

Answer 18

1. Lifestyle + dietary changes
2. Biguanide - Oral Metformin
3. Sulfonylurea - Oral gliclazide (HbA1c >53mmol/L 16wks)
4. HbA1c >57mmol/L 6mths
   - Isophane insulin

Question 19

Hyperkalaemia - Treatment

Answer 19

Calcium gluconate

Question 20

Hepatic extraction ratio

Answer 20

Proportion of drug removed by one passage through liver

Question 21

EC50

Answer 21

EC50 = conc that gives half the maximal response