11 Adrenergics II Flashcards Preview

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Flashcards in 11 Adrenergics II Deck (50):

Postsynaptic adrenergic receptors (alpha 1, beta 1, beta 2, and DA 1 are primarily located in 4 major areas which are?

1) Cardiac Muscle
2) Smooth Muscle
3) Glands
4) Renal vasculature


Drugs that stimulate adrenergic transmission are most commonly used for what?

Hypotensive therapies


Drugs that inhibit adrenergic transmission are most commonly used for what?

Hypertensive therapies.


Would you inhibit or stimulate adrenergic transmission to increase blood flow to the skin and splanchnic areas?

You would inhibit adrenergics.


post ganglionic nerve terminal receptors are alpha 2 and DA 2. Agonist of these receptors have what effects on the body?

They deplete NE agents decreasing the sympathetic response. (This is because they are neg. feedback looping)


T/F A post-junctional antagonist of adrenergic receptors has the same overall effect as an agonist of pre-junctional adrenergic receptors?



Clonidine, Guanabenz, and alpha methyldopa are examples of what type of drug?

alpha 2 receptor agonists.


An alpha 2 receptor agonist would cause decreased peripheral resistance, decrease heart rate, and decrease C.O. What effect does an alpha 2 receptor have on blood pressure?

Decreased blood pressure would be observed. However, alpha 2 agonists do not affect baroreceptor reflexes and rarely elicit orthostatic hypertension.


Alpha 2 agonist have side effects which include?

1) sedation
2) xerostomia
3) anorexia
4) fluid retention
5) Vivid dreams and CNS stimulation.


Bromocriptine is an example of what type of drug?

D2 receptor agonist.


Bromocriptine is primarily used as an anti parkinsons agent. What are some of its peripheral side effects?

1) postural hypotension
2) cardiac arrhythmia


T/F D2 receptors on post synaptic effector sites in the CNS are involved in negative feedback inhibition?

False. They are not, only in the periphery.


Reserpine is considered a NE depleting drug. How does it work? How long does it act.

1) It depletes stores of biogenic amines (Epi, norepi, DA, serotonin) in both the CNS and PNS by blocking transport into storage vesicles.
2) It has a long duration of action.


Reserpine has side effects which include?

1) sedation
2) depression
3) Parkinsonian symptoms
4) Increased GI motility leading to ulcers.


what function does Guanethidine have?

it prevents the release of NE (only) by stabilizing neuronal membranes and interfering with exocytosis.


How does guanethidine get into the nerve terminal?

through the amine 1 transporter


what effect does cocaine and tricyclic antidepressants (NET inhibitors) have on guanethidine activity?

They both block its activity because guanethidine has to first be taken up by amine 1 transporter to be effective. If this transporter is shut down, then guanethidine becomes ineffective.


Why would you give your patient guanethidine?

You would give it to them as an anti hypertensive.


Alpha methyldopa is a drug used for?

anti hypertension


how does alpha methyldopa work?

Alpha methyldopa replaces DOPA in the synthesis of NE. The result is that you no longer get pure NE but rather alpha methly NE which elicits a much weaker response than pure NE.


T/F Alpha methyl NE (MNE) is described as a False Neurotransmitter?

True. It takes the place of NE but does not do the same level of action.


Is MNE (methyl NE) able to get into the CNS? What does it do?

Yes. This is how it acts as an anti hypertensive. It targets the brain stem affecting the vasomotor center.


what are some of the chronic side effects of methyl NE?

hemolytic anemiahepatitisleukopenialupus like problems.


an alpha 1 adrenergic blocker would have what effects?

inhibit constriction/contraction resulting in lower MAPRelieve inhibition on GI


Which type of alpha 1 antagonists are reversible? Irreversible?

reversible=competitiveIrreversible=non competitive


T/F Beta 1 blocker inhibit cardiac output?



Phenoxybenzamine is an example of what type of drug?

alpha 1 adrenergic blocker.


Is phenoxybenzamine competitive or non competitive? and how does it work?

1) Non competitive
2) It covalantly binds to the alpha 1 receptor blocking its activity. It also binds to amine I transport blocking its ability to reuptake NE.


Phenoxybenzamine usually works for 24 hours as an alpha 1 adrenergic blocker decreasing the sympathetic response. What ill effects will this drug have on the body?

Postural hypotensiontachycardia


T/F Phenoxybenzamine is used as treatment for pheochromocytomas?

true for the management of hypertension before surgery.


What is prazosin? competitive or non competitive?

Its an alpha 1 antagonistcompetitive


Prazosin can be used as an antihypertensive with little or no effect on tachycardia. Why would this be?

It is alpha 1 receptor selective. (No beta 1)


what does the drug phentolamine do?

its a competitive antagonist for the alpha 1 receptor. (Note that this drug is considered a dirty drug in that it inhibits both alpha 1 and alpha 2 receptors and can even interact with muscarinic and histamine receptors)


T/F The therapeutic use of phentolamine relates to its action on the B2 receptor?

False. Its action relates to the hypotensive effect is has by blocking alpha 1 receptors.


It was mentioned earlier that the drug phenoxybenzamine can be used to manage a pheochromocytoma. Can the drug Phentolamine also be used for this?



T/F most beta blockers are pure antagonists?

true. (This means that the agent binds the receptor but does not activate it)


Beta receptor inhibitors are widely used for?

hypertension therapy. (they are usually used in conjunction with diuretics)


why would you favor using a beta blocker over an alpha 1 blocker for treating a patient with asthma?

Because beta 1 receptor blockers are effective for treating hypertension, and less prone to induce bronchoconstriction because there is some beta 2 cross reactivity.


Propranolol, pindolol, timolol, and Nadolol are all examples of what type of drug?

1)beta 1 and beta 2 blockers (antagonists)


Why is Timolol widely used for glaucoma therapy?

it lowers the intraocular pressure


T/F Propranolol a beta 1 and 2 antagonist is an effective prophylactic treatment to prevent recurrence of Myocardial infarction?

True Because the beta 2 activity allows for dilation of the arteries/veins in the heart.


T/F Beta 2 antagonists should be given to those with hypertension and asthma?

False. Beta 2 antagonists can allow further bronchoconstriction because beta 2 usually relaxes smooth m. in the bronchioles.


Betaxolol, atenolol, metoprolol, and esmolol are all examples of which type of drug?

Beta 1 antagonists (specific)


T/F Metoprolol a beta 1 antagonist is an effective prophylactic agent to prevent recurrences of myocardial infarction?



Beta 1 adrenergic blockers (antagonists) target what?

they have cardiac specificity


what are some common side effects when using propranolol and metoprolol (beta 1 blockers)?



why do Nadolol and atenolol (beta 1 blockers) not cause as many side effects?

becuase they cannot cross the BBB


What is the biggest concern when using beta blockers?

they must be used with caution on patients with cardiac insufficiency because you decrease the HR, contractility, and C.O.


What are the 5 medical diseases listed that are usually treated with adrenergic antagonists?

1) pheochomocytoma (alpha 1 antagonist)
2)Hypertension (beta blockers main, alpha 1 can be used)
3) Ischemic heart disease (beta blockers)
4) Glaucoma (beta blockers)
5) urinary obstruction (alpha 1 treatment)


why are beta blockers used for glaucoma?

they lower intraocular pressure by reducing production of aqueous humor.