Symp Nervous System I by Prof. Krouse Flashcards
Why is NE given? On which receptor subtypes does it act? What is it weakest receptor subtype?
Does it cross the BBB?
Because it’s a pressor agent used in shock and hypotension.
Alpha and Beta; weakest @ B2
No.
Why is EPI given? On which receptor subtypes does it act? What is its weakest receptor subtype?
Does it cross the BBB?
Allergic Reaction, shock
Powerful agonist on all receptor subtypes; weakest on B3.
No.
Why is isoproterenol given? On which receptor subtype does it act? Why is its degredation unusual?
Asthma (but better agents) and cardiac stimulant. Non-selective Beta agonist. Only COMT breaks it down.
Why is dopamine given?
Explain the dose effect it produces (low, medium, high) on receptor subtypes.
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
Why is fenoldopam given? What is its mechanism of action?
Acute hypertension, renal failure
D1 receptor agonist
How does fenoldopam work?
D1 receptor agonism causes vasodilation and sodium excretion in the kidney
Why is Albuterol given? On which receptor subtype does it work? What is the net effect?
Asthma, COPD
B2 agonist; bronchodilator
Why is ritodrine given? On which receptor subtype does it work? What is its net effect?
Premature labor; B2 agonist; smooth muscle relaxer (?)
Why is Salmeterol given? On which receptor subtype does it work? What is its net effect?
asthma, COPD; long-acting beta-adrenergic (B2) agonist; bronchodilator
What are the side effects of selective beta2 agonists used for asthma or COPD?
Hypotension, Reflex tachycardia
Why is dobutamine given? On which receptor subtype does it work?
How does it work?
Congestive heart failure; B1 agonist
IV infusion increases CO by increasing force of contraction without increasing 02 demand or HR
What does phenylphrine treat? On which receptor subtype does it work?
nasal decongestant, limited clinical use in treating hypotension or shock; alpha1 agonist
What does methoxamine treat? On which receptor subtypes does it work?
hypotension; pressor agent; alpha1 agonist
What does Clonidine treat?
On which receptor subtype does it act?
What is its net effect?
Hypertension; opioid withdrawl
a2 - decreased CNS sympathetic outflow; inhibits NE release
Why is it important that patients are tapered off Clonidine?
They could develop rebound hypertension.
What does alpha-methyl-dopa treat? How does it work?
Hypertension, especially during pregnancy
Alpha 2 receptor agonist, decreased CNS sympathetic outflow; inhibits NE release
What are the side effects of alpha 2 receptor agonists like Clonidine and alpha-methyl-dopa?
Impotence, dry mouth, rebound hypertension, sedation
Why is dex(medetomidine) used? Receptor Subtype? Respiratory depression?
sedation/analgesia (during surgery); A2 agonist; NO.
What does Tizanidine treat? What affects its metabolism?
short term muscle spasticity (whiplash)
CYP1A2 inhibitors - cipro and cimetidine
What does Pramiprexole treat? Receptor Subtype? Side-effect?
Parkinsons Disease; Restless leg syndrome; Dopamine agonist
side-effect: drowsiness
What is the treatment progression for a patient with Parkinsons Disease?
1) L-Dopa + carbidopa (decarboxylase inhibitor)
2) Dopamine agonists – pramiprexole
3) MAOIs
4) Anticholinergics like benzotropine
5) COMT Inhibition
What are amphetamines used to to treat?
narcolepsy, hyperactivity
Methylphenidate treats what?
ADHD
What are the side effects of amphetamines and methylphenidate?
Tolerance, tachyphylaxis, restlessness, tremor
What is tachyphylaxis? What causes it?
an acute (sudden) decrease in the response to a drug after its administration
Depletion of NT or depletion of receptors for NT
Why is Ephedrine used? What’s its mechanism of action?
Nasal decongestant;
mixed response – direct action via alpha and beta receptors; indirect via release of NE
In what foods is tyramine found? What does it interact with?
Red wine and cheese; MAOIs, leading to hypertension
Where are the sites of action for tricyclic antidepressants?
inhibit neuronal uptake
Atomoxetine treats what? Whats its mechanism of action?
ADHD; inhibit NE neuronal uptake
Imipramine and Amitriptylline treat what? What are their drug classification?
Depression; TCA; inhibits neuronal uptake
Tranylcypromine treats what? How does it work?
Depression; non-selective MAOI,
What is the danger of using tranylcypromine with tyramine?
Explain the mechanism of action of this side effect.
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.
What does Selegiline treat? How does it work?
Parkinson’s Disease; selective MAOI
How do Tolcapone and Entacapone work? What do they treat?
COMT inhibitors. Last line of defense in Parkinson’s treatment
What does halperidol treat?
Schizophrenia
