Autonomic pharmacology pt. 2

Question 1

Where are B1 adrenergic receptors located? What is the effect of stimulation of these receptors?

Answer 1

Heart - stimulation causes increased HR and stroke volume

Question 2

Where are B2 adrenergic receptors located? What is the effect of stimulation of these receptors?

Answer 2

Lungs - stimulation causes bronchodilation

Question 3

Where are a1 adrenergic receptors located? What is the effect of stimulation of these receptors?

Answer 3

Blood vessels - effect is vasoconstriction

Question 4

What does the vagus nerve do to heart rate?

Answer 4

Slows it down

Question 5

How does serotonin cause migraines?

Answer 5

Constriction of extracranial and intracranial vessels (phase 1)

Question 6

What does serotonin do to bronchial and GI smooth muscle?

Answer 6

Constriction

Question 7

What does serotonin do to skeletal muscle blood vessels and sensory nerve endings?

Answer 7

Dilates skeletal muscle blood vessels and stimulates sensory nerve endings.

Question 8

What is the main metabolite of serotonin? How is this used clinically?

Answer 8

5-HIAA. 24 hour urine levels can be used to diagnose carcinoid syndrome.

Question 9

Can serotonin agonists be used prophylactically for migraines? Why or why not?

Answer 9

Nope because these drugs result in constriction of cranial vessels (used during phase 2) and that can precipitate a migraine.

Question 10

What are the two phases of migraine?

Answer 10

1. Vasoconstriction

2. Vasodilation

Question 11

___ levels of serotonin in the CNS is associated with depression.

Answer 11

Low

Question 12

What are ergot alkaloids? What is one clinical use for them? What will too much do?

Answer 12

Serotonin agonists, used sometimes for treatment of migraines. Too much can cause convulsive ergotism and hallucinations.

Question 13

Name the symptoms of a migraine headache.

Answer 13

Prodroma: Visual disturbances (aura). Then peripheral neuropathy, nausea/vomiting, sonophobia, photophobia.

Question 14

Can neurotransmitter and/or receptor levels change over time? What is the clinical significance of this?

Answer 14

They do change so patients must be weaned off medications slowly.

Question 15

Name the headache type that is more common amongst males. What are the symptoms of this type of headache?

Answer 15

Cluster headache. Symptoms include pain on one side of the face, runny nose.

Question 16

What is melatonin involved in?

Answer 16

Sleep/wake cycles.

Question 17

Where are a2-adrenergic receptors found? What does stimulation of these receptors do?

Answer 17

They are found on presynaptic neurons in the brain. Stimulation by epi and norepinephrine results in inhibition of release of epi and norepinephrine and subsequent inhibition of adenylate cyclase.

Question 18

Name the drug that is given to Parkinson’s patients because it can cross the blood-brain barrier.

Answer 18

L-dopa

Question 19

What is Clonidine and what does it do?

Answer 19

It is a sympatholytic that decreases sympathetic neurotransmitter release by stimulating alpha-2 receptors to decrease blood pressure.

Question 20

What type of receptor do sympatholytics such as Clonidine act on?

Answer 20

Alpha-2 - remember that these receptors result in inhibition of adenylate cyclase and subsequent decrease in NT release.

Question 21

Parasympathetic activity _______ tear and saliva production.

Answer 21

increases

Question 22

Is the action of the adrenal gland one reason why the sympathetic division can override the parasympathetic division?

Answer 22

Yeah

Question 23

In what cellular location does MAO act? What about cholinesterases?

Answer 23

MAO does its business inside the neuron. Cholinesterases degrade NTs in the cleft.

Question 24

What is atropine?

Answer 24

An Ach-muscarinic antagonist med that inhibits PNS physiologic responses.

Question 25

What is the mechanism of action of neuromuscular blockers? What is the difference between a depolarizing and non-depolarizing NMB?

Answer 25

These are Ach receptor antagonists. Depolarizing blockers noncompetitively bind receptors and cause spastic paralysis. Non-depolarizing blockers bind competitively and inhibit muscle contraction (flaccid paralysis).

Question 26

What are the two methods of action of cholinomimetics?

Answer 26

Directly binding receptors or inhibiting cholinesterase activity.

Question 27

What is one mechanism by which many antidepressant medications work?

Answer 27

By preventing reuptake by presynaptic catecholaminergic neurons to increase neurotransmitters in the cleft.

Question 28

Name two sympatholytic drugs and what they do.

Answer 28

Methyl dopa reduces release of norepi to reduce BP. Clonidine is an alpha-2 receptor agonist to reduce epi, norepi and reduce BP.

Question 29

How can tyramine cause a hypertensive crisis? Where is tyramine found? Which drug amplifies this pathway?

Answer 29

Tyramine displaces norepi from vesicles so lots of norepi is released, increasing BP. Alpha-2 receptors are unable to control norepi release since they are outside vesicles and free to diffuse to the post-synaptic neuron. Tyramine can be found in some aged cheeses, beer, red wine. MAOIs make it way worse.

Question 30

Should clonidine be given concomitantly with antidepressants?

Answer 30

Nope, they do opposite things!

Question 31

Beta adrenergic receptors act through the activation of _______ ________.

Answer 31

adenylate cyclase

Question 32

What drug should not be used in a post-MI patient with asthma?

Answer 32

Non-specific beta blockers.

Question 33

Funky levels of _______ can cause carcinoid syndrome, depression, flushing of the face, migraines, and altered sleep patterns.

Answer 33

serotonin

Question 34

What is o-methyl serotonin?

Answer 34

Melatonin

Question 35

In what two organs is serotonin found?

Answer 35

Brain, GI tract.

Question 36

What drug type can be used off label to manage anxiety?

Answer 36

Beta blockers

Question 37

What is carcinoid syndrome?

Answer 37

Flushing, hypotension, diarrhea, right heart failure. Caused by high serotonin levels released by the carcinoid tumors.

Question 38

Can you treat migraines prophylactically with drugs that prevent vasoconstriction?

Answer 38

Yeah

Question 39

What is propranolol? And what are its indications/ contraindications?

Answer 39

A non-specific beta blocker that can be used to reduce stress on the heart post MI. Should not be used in asthmatics because it wall cause bronchoconstriction.