Symp Nervous System I by Prof. Krouse

Question 1

Why is NE given? On which receptor subtypes does it act? What is it weakest receptor subtype?

Does it cross the BBB?

Answer 1

Because it’s a pressor agent used in shock and hypotension.

Alpha and Beta; weakest @ B2

No.

Question 2

Why is EPI given? On which receptor subtypes does it act? What is its weakest receptor subtype?

Does it cross the BBB?

Answer 2

Allergic Reaction, shock

Powerful agonist on all receptor subtypes; weakest on B3.

No.

Question 3

Why is isoproterenol given? On which receptor subtype does it act? Why is its degredation unusual?

Answer 3

Asthma (but better agents) and cardiac stimulant. Non-selective Beta agonist. Only COMT breaks it down.

Question 4

Why is dopamine given?

Explain the dose effect it produces (low, medium, high) on receptor subtypes.

Answer 4

To treat septic shock.

Low dose: activates DA(R)s which can stimulate or inhibit cAMP levels

Moderate dose: activates Beta1 receptors (Gs)
- secondline drug for heart failure to increase cardiac output

High dose: activates alpha1 receptors (Gq)
- vasoconstriction

Question 5

Why is fenoldopam given? What is its mechanism of action?

Answer 5

Acute hypertension, renal failure

D1 receptor agonist

Question 6

How does fenoldopam work?

Answer 6

D1 receptor agonism causes vasodilation and sodium excretion in the kidney

Question 7

Why is Albuterol given? On which receptor subtype does it work? What is the net effect?

Answer 7

Asthma, COPD

B2 agonist; bronchodilator

Question 8

Why is ritodrine given? On which receptor subtype does it work? What is its net effect?

Answer 8

Premature labor; B2 agonist; smooth muscle relaxer (?)

Question 9

Why is Salmeterol given? On which receptor subtype does it work? What is its net effect?

Answer 9

asthma, COPD; long-acting beta-adrenergic (B2) agonist; bronchodilator

Question 10

What are the side effects of selective beta2 agonists used for asthma or COPD?

Answer 10

Hypotension, Reflex tachycardia

Question 11

Why is dobutamine given? On which receptor subtype does it work?

How does it work?

Answer 11

Congestive heart failure; B1 agonist

IV infusion increases CO by increasing force of contraction without increasing 02 demand or HR

Question 12

What does phenylphrine treat? On which receptor subtype does it work?

Answer 12

nasal decongestant, limited clinical use in treating hypotension or shock; alpha1 agonist

Question 13

What does methoxamine treat? On which receptor subtypes does it work?

Answer 13

hypotension; pressor agent; alpha1 agonist

Question 14

What does Clonidine treat?

On which receptor subtype does it act?

What is its net effect?

Answer 14

Hypertension; opioid withdrawl

a2 - decreased CNS sympathetic outflow; inhibits NE release

Question 15

Why is it important that patients are tapered off Clonidine?

Answer 15

They could develop rebound hypertension.

Question 16

What does alpha-methyl-dopa treat? How does it work?

Answer 16

Hypertension, especially during pregnancy

Alpha 2 receptor agonist, decreased CNS sympathetic outflow; inhibits NE release

Question 17

What are the side effects of alpha 2 receptor agonists like Clonidine and alpha-methyl-dopa?

Answer 17

Impotence, dry mouth, rebound hypertension, sedation

Question 18

Why is dex(medetomidine) used? Receptor Subtype? Respiratory depression?

Answer 18

sedation/analgesia (during surgery); A2 agonist; NO.

Question 19

What does Tizanidine treat? What affects its metabolism?

Answer 19

short term muscle spasticity (whiplash)

CYP1A2 inhibitors - cipro and cimetidine

Question 20

What does Pramiprexole treat? Receptor Subtype? Side-effect?

Answer 20

Parkinsons Disease; Restless leg syndrome; Dopamine agonist

side-effect: drowsiness

Question 21

What is the treatment progression for a patient with Parkinsons Disease?

Answer 21

1) L-Dopa + carbidopa (decarboxylase inhibitor)
2) Dopamine agonists – pramiprexole
3) MAOIs
4) Anticholinergics like benzotropine
5) COMT Inhibition

Question 22

What are amphetamines used to to treat?

Answer 22

narcolepsy, hyperactivity

Question 23

Methylphenidate treats what?

Answer 23

ADHD

Question 24

What are the side effects of amphetamines and methylphenidate?

Answer 24

Tolerance, tachyphylaxis, restlessness, tremor

Question 25

What is tachyphylaxis? What causes it?

Answer 25

an acute (sudden) decrease in the response to a drug after its administration

Depletion of NT or depletion of receptors for NT

Question 26

Why is Ephedrine used? What’s its mechanism of action?

Answer 26

Nasal decongestant;

mixed response – direct action via alpha and beta receptors; indirect via release of NE

Question 27

In what foods is tyramine found? What does it interact with?

Answer 27

Red wine and cheese; MAOIs, leading to hypertension

Question 28

Where are the sites of action for tricyclic antidepressants?

Answer 28

inhibit neuronal uptake

Question 29

Atomoxetine treats what? Whats its mechanism of action?

Answer 29

ADHD; inhibit NE neuronal uptake

Question 30

Imipramine and Amitriptylline treat what? What are their drug classification?

Answer 30

Depression; TCA; inhibits neuronal uptake

Question 31

Tranylcypromine treats what? How does it work?

Answer 31

Depression; non-selective MAOI,

Question 32

What is the danger of using tranylcypromine with tyramine?

Explain the mechanism of action of this side effect.

Answer 32

hypertensive crisis

Tyramine boosts NE production, more NE is made from tyramine, and more NE is displaced from the vesicles. Without MAO active, more tyramine leads to more displacement, leading to hypertensive crisis.

Question 33

What does Selegiline treat? How does it work?

Answer 33

Parkinson’s Disease; selective MAOI

Question 34

How do Tolcapone and Entacapone work? What do they treat?

Answer 34

COMT inhibitors. Last line of defense in Parkinson’s treatment

Question 35

What does halperidol treat?

Answer 35

Schizophrenia