Pharmacology of the ANS

Question 1

Activation of the nicotinic ACh receptors results in

Answer 1

Spasm/Fasciculation

Question 2

Blockade of nicotinic ACh receptors results in

Answer 2

Flaccid paralysis

Question 3

The cholinergic toxidrome comprises of

Answer 3

Diarrhoea, urination, miosis, bronchospasm, bradycardia, emesis, lacrimation, salivation

Question 4

What are the treatments for the cholinergic toxidrome?

Answer 4

Atropine (muscarinic antagonist) and pralidoxime (regenerates AChE)

Question 5

Quaternary amines can/cannot cross the BBB

Answer 5

Cannot

Question 6

What structural feature of the compound bethanecol gives rise to its reduced effect on nicotinic receptors?

Answer 6

The beta methyl group

Question 7

What side group do carbechol and bethanecol share that reduces the effect of AChE on the compound?

Answer 7

NH2

Question 8

What is the principle difference between bethanechol and carbechol?

Answer 8

Carbechol acts on nicotinic receptors (lacks the beta methyl group)

Question 9

Pilocarpine is used in what three situations?

Answer 9

Glaucoma therapy, Sjogren’s syndrome, sweat test in CF

Question 10

What is the difference between pyridostigmine and physiostigmine?

Answer 10

Pyridostigmine is a quaternary amine and therefore will not cross the BBB. Physostigmine is a tertiary amine and crosses the BBB. It is therefore useful in the treatment of anti-cholinergic toxicity.

Question 11

What are the features of the anti-cholinergic toxidrome?

Answer 11

Dry as a bone, red as a beet, hot as hare, mad as a hatter, blind as a bat (loss of lens accom)

Question 12

What are the uses of benztropine and trihexyphenidyl?

Answer 12

Anticholinergics for the treatment of SM symptoms of Parkinson’s disease

Question 13

Activation of alpha 1 receptors leads to…

Answer 13

Vasocontriction

Question 14

Activation of alpha 2 receptors leads to…

Answer 14

Vasodilation

Question 15

Activation of beta 1 receptors leads to…

Answer 15

Increased heart rate and contractility

Question 16

Activation of beta 2 receptors leads to…

Answer 16

Vasodilation

Question 17

Epinephrine and dopamine activate…

Answer 17

All receptor subtypes

Question 18

Isopreteronol and qobutamine activate…

Answer 18

Predominantly the beta receptors, but dobutamine also exerts an effect on alpha receptors

Question 19

Norepinephrine and phenylephrine activate…

Answer 19

Alpha receptors, with some effect on beta receptors in the case of NE

Question 20

What is the MOA of Clonidine and Methyldopa?

Answer 20

Activation of alpha 2 receptors in the CNS

Question 21

What drugs should you avoid in cocaine intoxication?

Answer 21

Beta blockers; their administration leads to unopposed alpha receptor activation and severe hypertension.

Question 22

What drug is given to blunt the cheese effect?

Answer 22

Phentolamine; an non-selective alpha blocker

Question 23

What is the MOA of mirtazepine?

Answer 23

Alpha 2 receptor blockade in the CNS

Question 24

What is the effect of dobutamine on CO, MAP, and HR?

Answer 24

Increased CO, reduced MAP, and increased HR

Question 25

What is the effect of dopamine/E on CO, MAP, and HR?

Answer 25

Increased CO, increased MAP, and increased HR

Question 26

What is the effect of NE on CO, MAP, and HR?

Answer 26

Increased CO, HR may be increased or decreased (increased when there is B1 activation, but decreased on account of reflex bradycardia), and a significant increase in the MAP.

Question 27

What is the effect of isoproterenol on CO, MAP, and HR?

Answer 27

Increased CO, increased HR, and a fall in the MAP. The pulse pressure is significantly increased.

Question 28

What is the effect of phenylephrine on CO, MAP, and HR?

Answer 28

Decreased CO (secondary to increased afterload), decreased HR, and increased MAP.

Question 29

What is the major effector neurotransmitter of the SNS?

Answer 29

Norepinephrine

Question 30

What is the major effector neurotransmitter of the PSNS?

Answer 30

Acetylcholine

Question 31

Is NE or acetylcholine the effector neurotransmitter at the adrenal gland?

Answer 31

Acetylcholine, despite being under the remit of the SNS

Question 32

What does activation of the alpha 1 receptor lead to?

Answer 32

Vasoconstriction at arterioles

Question 33

What does activation of the beta 2 receptor lead to?

Answer 33

Bronchodilation, relaxation of smooth muscle in the blood vessels of skeletal muscle and liver.

Question 34

Why does the parasympathetic nervous system lead to penile erection, for example?

Answer 34

It is as a result of an indirect effect of acetylcholine; triggers the release of nitric oxide which results in smooth muscle relaxation.

Question 35

Beta 2 receptors in the lungs are more responsive to NE than to E. True or False

Answer 35

False; Beta 2 receptors in the lungs are more responsive to E and this is the basis for the use of this drug in bronchospasm caused by anaphylaxis.

Question 36

Is micturition a product of SNS or PSNS activation?

Answer 36

PSNS activation

Question 37

What effect will epinephrine have on glucose metabolism?

Answer 37

Increase glycolysis and gluconeogenesis; decreases insulin release via its effect on alpha 2 receptors in the pancreas.

Question 38

Activation of the Gi subtype of G-protein coupled receptor results in…

Answer 38

Decreased levels of cAMP, decreased cardiac contractility

Question 39

What is the function of protein kinase A in cardiac myocytes?

Answer 39

Calcium influx into the cell.

Question 40

What does cAMP do in vascular smooth muscle?

Answer 40

It inhibits myosin light chain kinase and reduces contractility.

Question 41

Gq receptors are associated with what receptor in SNS?

Answer 41

Alpha 1 receptors