Pharmacology

Question 1

pharmacokinetics?

Answer 1

how the body affects the drug; Absorption, Distribution,

Metabolism and Excretion (ADME)

Question 2

pharmacodynamics ?

Answer 2

how the drug affects the body

Question 3

receptor types?

Answer 3

ligand gated ion channels (eg, nicotinic ACh), G coupled receptors (eg, beta adrenoceptors), kinase linked receptors (eg, GF) and cytosolic receptors (eg, steroids)

Question 4

potency?

Answer 4

measure of how well a drug works

Question 5

affinity?

Answer 5

how well a ligand binds to the receptor

Question 6

efficacy?

Answer 6

how well a ligand activates the receptor?

antagonists have 0 efficacy

Question 7

isoprenaline?

Answer 7

non-selective beta adrenoceptor agonist so it activates B1 in the heart and B2 in the lungs

Question 8

salbutamol

Answer 8

selective B2 adrenoceptor agonist

Question 9

eg of enzymes as drug targets?

Answer 9

NSAIDS that inactivate COX responsible for the breakdown of
arachidonic acid to prostaglandin H2
(aspirin irreversibly blocks the active site)

Question 10

transporters as drug targets eg?

Answer 10

PPI (omeprazole) irreversibly inhibit proton pump

Question 11

ion channels as drug targets eg?

Answer 11

CCB eg, amlodipine

Question 12

bio-availability?

Answer 12

amount of drug taken up as a proportion of the amount

administered

Question 13

aspirin in the gut?

Answer 13

Aspirin is acidic
• In the stomach the acidic tablet dissolves but it then becomes less
ionised due to the fact that a weak acid (such as aspirin) becomes less ionised in lower pH and movement of un-ionised aspirin across gut is rapid.

Question 14

which molecules are distributed where?

Answer 14

Proteins/large molecules are only active in the plasma compartment (5L) eg, warfarin
- Water soluble molecules are active in plasma and interstitial compartment
(5L + 15L) eg, NSAIDS
- Lipid soluble molecules are only active in the intracellular fluid (45L) eg, paracetamol

Question 15

volume of distribution equation?

Answer 15

Volume of distribution = Total amount of drug in body ➗ Concentration
of drug in plasma

Question 16

clearance?

Answer 16

The volume of plasma that can be completely cleared of drug per unit
time (mls minute-1 (ml/min))

Question 17

water soluble v larger molecules in kidney elimination?

Answer 17

Water soluble molecules which pass through the glomerular endothelia
gap are eliminated by glomerular filtration
• Larger water soluble molecules can be eliminated by active tubular
secretion

Question 18

hepatic extraction ratio?

Answer 18

The proportion of drug removed by one passage through the liver

Question 19

phase I reaction - where do they occur?

Answer 19

95% of phase I reactions are in liver smooth endoplasmic

reticulum

Question 20

what is phase 1 reactions?

Answer 20

make the drug more hydrophilic so that it can be excreted by the kidneys - it does this by adding a hydroxyl group to the drug

Question 21

cytochrome p450?

Answer 21

microsomal enzyme found in liver SER and involved in phase 1 reactions

Question 22

phase 2 reactions?

Answer 22

conjugation reactions, glucuronodiation and used if drug is very hydrophobic

Question 23

somatic NS neurotransmitter

Answer 23

ACh

Question 23

somatic NS neurotransmitter

Answer 23

ACh

Question 24

autonomic NS neurotransmitter?

Answer 24

ACh and NAd

Question 25

ACh - parasympathetic NS receptor?

Answer 25

- muscarninc Ach receptors (M1,M2,M3)

Question 26

ACh - sympathetic NS receptor?

Answer 26

- ACh mediates release of Ad and NAd

Question 27

ACh in somatic NS?

Answer 27

-nicotonic receptors at neuromuscular junction

Question 28

adverse effects of muscarninic agonists?

Answer 28

DUMBELS muscarninc = parasympathetic diarrhoea, urination, miosis, bradycardia, emesis, lacrimation and salvation/sweating

Question 29

catacolamine synthesis?

Answer 29

TYROSINE > DOPA > dopamine > noradrenaline > adrenaline

Question 30

alpha 1 adrenergic receptors?

Answer 30

causes vasoconstriction, pupil dilation and bladder contraction BLOOD VESSELS AND BLADDER

Question 31

alpha 2 Adrenergic receptors?

Answer 31

presynaptic inhibition of noradrenaline

Question 32

beta 1 adrenoceptor?

Answer 32

increased force of heart contraction, increases heart rate and increased electrical conduction in heart IN HEART!

Question 33

beta 2 adrenoceptor?

Answer 33

bronchodilator, vasodilation and reduces GI motility | BRONCHIAL SMOOTH MUSCLE - LUNGS

Question 34

beta 3 adrenoceptor?

Answer 34

increases lipolysis and relaxes bladder | BLADDER

Question 35

nociceptive pain?

Answer 35

Inflammatory chemicals reach nerves to stimulate pain

Question 36

neuropathic pain?

Answer 36

Where the nerve is directly inured - pain originates in nervous system

Question 37

pain pathway?

Answer 37

Noxious stimulus 2. Nociceptors 3. Spinal cord (ascending pathway) 4. Spinal cord modulation 5. Thalamus 6. Cortical areas, somatosensory cortex & prefrontal cortex 7. Pain experience & memory

Question 38

tissue injury pathway?

Answer 38

The breakdown of membrane lipids leads to the formation of arachidonic acid under the action of the enzyme phospholipase A2 - Arachidonic acid is then converted to prostaglandins under the action of the enzyme cyclooxygenase (Cox) - Prostaglandins are irritants to nerve fibres and stimulate pain

Question 39

nerve fibres transmitting pain?

Answer 39

C and A delta fibres

Question 40

C fibres?

Answer 40

Unmyelinated | Characterised by diffuse dull intense pain

Question 41

A delta fibres?

Answer 41

Small and myelinated | Conduct localised sharp sensation

Question 42

Gate control theory

Answer 42

If A beta fibres ARE stimulated then the pain signal is halted and does not reach the brain and is thus not perceived - This means that low intensity stimulation of the skin or peripheral nerves or vibration in order to stimulate the A beta fibres will generate analgesia

Question 43

Type A - adverse drug reaction?

Answer 43

Augmented eg, anti-coagulants causing bleeding

Question 44

Type B - adverse reactions?

Answer 44

Bizarre; unexpected, unrelated and unpredictable

Question 45

Type C - adverse reactions?

Answer 45

chronic eg, steroids predispose to hypoglycaemia - resulting in diabetes

Question 46

Type D - adverse reactions?

Answer 46

delayed

Question 47

Type E - adverse reactions?

Answer 47

End of use; withdrawal reactions

Question 48

oral contraceptives and antibiotics?

Answer 48

interaction causing motility changes

Question 49

oral availability of morphine?

Answer 49

50%