Drugs part 2

Question 1

Structure of adrenoceptors

Answer 1

G protein coupled receptors

single polypeptide chain, 7 transmembrane alpha helices

Question 2

alpha 1 adrenoceptor

Answer 2

binds to noradrenaline
Gq associated
alpha subunit dissociates and binds to phospholipase C
generates IP3 and DAG
IP3 binds to receptor on ER, causes calcium release
DAG activates PKC

Question 3

Alpha 2 adrenoceptor

Answer 3

Gi protein (inhibitory)
alpha subunit inhibits to adenylyl cyclase
decreased PKA

Question 4

beta 1,2 and 3 adrenoceptors

Answer 4

Noradrenaline
Gs protein
stimulates adenylyl cyclase
increased PKA

Question 5

Where are beta 1 adrenoceptors found and what do they do?

Answer 5

Heart

increase heart rate, conduction velocity and increased contraction

Question 6

What do beta 2 adrenoceptors cause?

Answer 6

dilation of blood vessls and bronchi

ciliary muscle relaxation

Question 7

Which adrenoceptors cause blood vessel constriction?

Answer 7

Alpha 1 and 2

Question 8

When can dobutamine be used as an adrenoceptor agonist?

Answer 8

beta 1 receptor agonist

heart failure, heart block

Question 9

What are the differences between nicotinic and muscarinic AChRs?

Answer 9

Nicotinic receptors are ionotropic - acts as a channel for positively charged ions (sodium) to flow to cause depolarisation, all are excitatory
Muscarinic receptors are G protein coupled receptors, can be excitatory or inhibitory

Question 10

M1 Muscarinic receptors

Answer 10

neural, including ganlia in stomach

IP3 pathway

Question 11

M2 muscarinic receptors

Answer 11

cardiac

inhibits cAMP pathway

Question 12

M3 muscarinic receptors

Answer 12

smooth muscle

increases IP3 stimulation

Question 13

clinical uses of antimuscarinic drugs

Answer 13

asthma
bradycardia
to decrease gut motility
urinary incontinence

Question 14

Drugs for GORD (supression of acid)

Answer 14

proton pump inhibitors (omeprazole)
H2 blockers - blockers histimine which stimulates acid secretion
Antacids increase pH
alginates form a physical barrier

Question 15

What is helicobacter pylori and what can it cause?

Answer 15

gram negative bacteria
peptic ulcers disease - gastritis
hypergastrinaemia - increases gastrin release and decrease somatostatin release

Question 16

What can be used to treat IBD?

Answer 16

aminosalicylcates 
immunomodulators 
corticosteroids
biologics 
- blocks TNF-a which is an inflammatory cytokine

Question 17

Types of laxatives

Answer 17

stimulant
osmotic
bulk

Question 18

Anti-diarrhoeals

Answer 18

loperamide
suppresses motility
allows more time for water to be absorbed

Question 19

What is suxamethonium apnoea?

Answer 19

occurs when this muscle relaxant has been given during surgery, patient can’t metabolise drug quickly enough, patient remains paralysed and unable to breathe after surgery

Question 20

What are the 4 categories of metabolising (and what do they metabolise)?

Answer 20

ultrarapid
extensive
intermediate
poor metabolisers
- cant metabolise CYP2D6

Question 21

What makes people high metabolisers?

Answer 21

High levels of CYP3A5

Question 22

What are examples of NSAIDs

Answer 22

aspirin
ibuprofen
paracetamol

Question 23

How do NSAIDs work?

Answer 23

Prevent the production of prostaglandins by inhibiting cyclooxygenase (COX)

Question 24

What are the 3 effects of NSAIDs?

Answer 24

analgesia - inability to feel pain
anti-inflammatory - PGs are involved in inflammation
anti-pyretic - reduce raised body temperature

Question 25

Which NSAID causes the irreversible inhibition of COX?

Answer 25

aspirin

Question 26

Which NSAID causes the reversible inhibition of COX?

Answer 26

ibuprofen

Question 27

Which NSAID causes the reversible non-competitive inhibition of COX?

Answer 27

paracetamol

Question 28

What is the difference between COX1 and COX2?

Answer 28

COX1 expressed by all cells | COX2 expressed by inflammatory cells

Question 29

Where are micerlocorticoids secreted from?

Answer 29

Outer zona glomerulosa

Question 30

Where are glucocorticoids secreted from?

Answer 30

middle zona fasciculata

Question 31

Where are adrenal androgens secreted from?

Answer 31

inner zona reticularis

Question 32

Mechanism of action of steroids

Answer 32

steroid receptors are inside the cell when ligand engages with receptor they homodimerise This causes translocation to the nucleus Interacts with promoter regions on genes

Question 33

negative feedback of glucocorticoid release

Answer 33

Hypothalamus reduces corticotrophin releasing factor This stimulates pituitary to release ACTH ACTH finds adrenal cortex Steroids released from cortex Negative feedback by secreted steroids