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Old 05-10-2012
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Drug Beta non-selective & seletive Mechanism Of Action

The diagnosis of emphysema is made in a patient 40-year-old 6 month ago, tonight arrives to the emergency room with headaches and blood pressure 155/98 mmHg, after a full evaluation the R4(a resident in 4 years) decides to let the patient go home with a prescription of propranolol. Which of the following will be happening in this patient in the future with this prescription?

A) Ameliorate the patient sign and symptom inconvenient
B) Improve the blood pressure 140/90 mmHg
C) Increased(cAMP, Na+, and Ca+) and decreased PR interval
D) Abnormal pacemakers by increasing slope of phase 4
E) Bronchoconstriction by blocking beta-2 receptors




:so rry::sorry::sorry:
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Last edited by alfjof; 05-10-2012 at 10:11 PM.
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Old 05-10-2012
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I say E. This is why you would prefer beta-1 selective in patients with lung disease.
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Old 05-10-2012
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never, ever give non-selective B-blockers to asthmatics or EPOC...
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clearly E)

+Dr.Mexito's comment - it can also mask the symptoms of hypoglycemia
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i will go with E too...

beta-blockers decrease slope of phase 4....

it does increase cAMP, but what does it do to PR interval... ?
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I believe non-selective B-blockers will prolong the PR interval, since the B1 receptor normally acts to increase conductance through the AV node. This decreased conduction seen in B-1 antagonism should translate into a prolonged PR interval. This could also explain why certain beta-blockers are used as Class III anti-arrhythmics.
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Quote:
Originally Posted by ..sharma View Post
i will go with E too...

beta-blockers decrease slope of phase 4....

it does increase cAMP, but what does it do to PR interval... ?
it's E as said before

beta 1 receptor works through adenyl cycklase, so beta 1 agonists will increase the level of cAMP. beta 1 blockers (like propranolol here) will decrease the level of cAMP in the cells.
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Quote:

beta 1 receptor works through adenyl cycklase, so beta 1 agonists will increase the level of cAMP. beta 1 blockers (like propranolol here) will decrease the level of cAMP in the cells.
oh... ya... thanks for pointing out... i always get them mixed up ..
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