Autonomic Pharmacology

Question 1

Why do all drugs that enter the blood stream have a direct effect on the autonomic nervous system?

Answer 1

Neurones of the ANS are outside of the BBB

Question 2

What is the class of drugs called that promotes the action of noradrenaline or inhibits the action of ACh on mAChR's?
Give an example

Answer 2

sympathomimetric

e.g. atropine (muscarinic/nicotinic anatagonist) binds to the mAChR and causes the dilation of pupils

Question 3

What is the class of drugs called that promotes the action of ACh on mAChR's or inhibit the action of noradrenaline?
Give an example

Answer 3

parasympathomimetric
muscarine, ACh and pilocarpine
propanolol (NA antagonist, slows HR and lowers BP)

Question 4

What effect does the botulinum toxin have?

What symptoms and signs does it produce?

Answer 4

stops exocytosis of ACh

Question 5

What does neostygmin do?

What is it used to treat?

Answer 5

increases ACh by inhibiting ACh breakdown by acetylcholineesterase
Treats myaesthenia gravis

Question 6

What type of drug is hexamethonium?
Where does it act?
In the past what was it used for?

Answer 6

selective antagonist for the neuronal subtype of nicotinic receptor
Non-competive so ACh can still bind but will have no effect
Acts at autonomic ganglionic receptors blocking all effects of ANS
Antihypertensive

Question 7

What often causes muscarine poisoning?
What are the adverse effects?
What is the cause of these effects?
What is the treatment?

Answer 7

ingesting certain mushrooms
bradycardia, vasodilation, hypotension
increased gut motility
salivation, lacrimation, airway secretion
Muscarine is a muscarinic against so stimulates parasympathetic action
Atropine which is an antagonist and blocks receptors

Question 8

What type of drug is pilocarpine?
What does it treat?
How?

Answer 8

Muscarinic agonist

Treats glaucoma, ciliary muscle constrict improving aqueous humour drainage, decreases intra-ocuclar pressure

Question 9

What are the 5 areas of adrenergic transmission pharmacology?

Answer 9

1. alpha-adrenoreceptor agonists/antagonists
2. beta-adrenoreceptor agonists/antagonists
3. Noradrenaline transporter blockers
4. Monoamine oxidase inhibitors
5. Indirectly acting sympathomimetic amines

Question 10

What are the 5 main sub-types of adrenoreceptors?

Answer 10

1. alpha 1 –> vasoconstriction
2. alpha 2 –> vasoconstriction, inhibits sympathetic outflow
3. beta 1 –> increase heart rate and contractility
4. beta 2 –> relax smooth muscle (vaso/bronchodilation)
5. beta 3 –> relax smooth muscle (bladder), stimulate lipolysis

Question 11

What class are adrenergic receptors in?

Answer 11

GPCR’s

Question 12

What are the main uses of alpha-receptor agonists? Give drug examples

Answer 12

vasoconstrictors with LA’s (adrenaline)
nasal decongestants (phenylephrine)
hypertension
facial erythema in rosacea (brimonidine)

Question 13

What are the 3 main uses of beta-receptor agonists?

Answer 13

cardiogenic shock - B1 (adrenaline)
anaphylatic shock - a/b (andrenaline)
asthma B2 (salbutamol)

Question 14

What are the 2 main uses of alpha antagonists?

Answer 14

hypertension (a1)

bening prostatic hyperplasia (a1)

Question 15

What are the 5 uses of beta antagonists? (beta blockers)

Answer 15

angina
hypertension
anxiety
heart failure
locally for glaucoma
e.g. metoprolol, propanolol

Question 16

Some drugs act by preventing reuptake of noradrenaline to be recycled. What affect does this have in terms of autonomic activity? Give one drug example

Answer 16

Enhances the effects of sympathetic activity

Cocaine/desipramine

Question 17

What are mono-amine oxidase inhibitors clinically used as?

What is their effect?

Answer 17

antidepressants

increase levels of noradrenaline, dopamine and 5-HT in the brain and peripheral tissues

Question 18

Give an example of an indirectly acting sympathetic amine?
What are they structurally related to?
Mimic effects of ………….. but are ……….. …………

Answer 18

amfetamine
noradrenaline
longer lasting

Question 19

What is the effect of botulinum toxin?

Answer 19

BT = blocks exocytosis of vesicles

Question 20

Why do drugs that affect neuronal NAChR’s not affect muscular NAChR’s?

Answer 20

Different structure
Muscular have an alpha1 subunit
Neuronal have an alpha2-7 subunit

Question 21

What are the symptoms of muscarine poisoning?

What is the treatment?

Answer 21

abdo pain/cramping
bradycardia
decreased BP
secretions into airways
airways contract 

muscarinic antagonist e.g. atropine

Question 22

What is pilocarpine used for?

What does it treat?

Answer 22

constricts pupil

glaucoma, stops XS secretions in aqueous humour

Question 23

Where are each of the muscarinc ACh receptors found?

Answer 23

M1 - stomach, salivary glands
M2 - cardiac
M3 - smooth muscle

Question 24

Which adrenoreceptors/muscarinic ACh receptors are connected to which G proteins?

Answer 24

A1 - Gq -->PLC
A2 - Gi --> decrease AC
All beta - Gs --> increase AC
M1 - Gq --> PLC
M2 - Gi --> decrease AC
M3 - Gq --> PLC