Beta Blockers Flashcards
What do selective beta blockers selectively block?
Beta-1 (heart chrontropy and inotropy)
No effect on beta-2
What effect do non-selective beta blockers have on the heart and lungs?
Decrease heart rate, decrease blood pressure, bronchoconstrict, vasoconstrict
What does it mean for a beta blocker to have intrinsic sympathomimetic activity (ISA)?
Beta blockers with some beta agonistic effects (blocks yet occasionally stimulates receptor)-generally less effective
When are beta blockers with ISA used?
When a patient is at risk of bottoming out
What is MSA?
Membrane stabilizing activity – has numbing affects due to inhibition of myocardial fast sodium channels
What type of medicine contains MSA?
Eyedrops used to treat glaucoma
Describe problems stemming from high lipophilicity of some beta blockers
Can penetrate blood brain barrier causing seizures and delirium
Name a beta blocker with ISA
Pindolol (has an “i” in it)
Name two beta blockers with MSA
Acebutolol, propranolol
List three lipophilic beta blockers
Carvedilol, nebivolol, penbutolol
Name two beta blockers with alpha-1 antagonism
Carvedilol, labetalol (do not end in “olol”)
Which type of beta blockers are the more potent antihypertensives?
Beta blockers with alpha-1 antagonism (recognized by “ilol” or “alol” ending)
Name a beta blocker with nitrous oxide release
Nebivolol (starts with N)
Name 3 beta-1 selective beta blockers
Atenolol, metoprolol, nebivolol, Acebutolol, betaxolol, esmolol…
Which patients should be careful to avoid nonselective beta blocker’s?
Patients with lung conditions due to beta blocker’s potential for bronchoconstriction
Describe the mechanism of action of beta blockers
Blockade of epinephrine and norepinephrine effects on beta adrenergic receptors, can be beta-1 selective or nonselective
What is the correct way to taper off of a beta blocker?
There is no correct way, just withdraw slowly due to receptor up regulation
What is the concern if a patient on beta blockers goes into anaphylaxis?
They require higher doses of epinephrine to mediate anaphylaxis
Why should diabetic patients be careful on beta blockers?
Beta blockers mask symptoms of hypoglycemia – sweating, tremor, headaches, tachycardia
How can beta blockers negativelycontribute to heart failure?
Beta blockers are negative inotropes that increase fill time but decrease contractility
What are three neurologic side effects of beta blockers
Depression, fatigue, sexual dysfunction
the higher the lipophilicity, the higher the risk
List 3 beta blockers that decrease mortality in congestive heart failure
Metoprolol, carvedilol, Bisoprolol
List a beta blocker that is renally eliminated
Atenolol
List a beta blocker that is IV only
Esmolol
List a beta blocker that is eliminated via plasma esterases
Esmolol (has nine minute half life, metabolized in blood, given IV only)
List a beta blocker that can be used in hypertensive emergency
Labetalol (more potent alpha blocker than carvedilol)
What medication should be used to treat Prinzmetal’s angina?
Calcium channel blockers (vascular specific) – beta blockers worsen vasospasm
Which is a more potent form of labetalol (nonselective beta blocker with alpha-1 blockade), PO or IV?
PO Labetalol is a more potent alpha blocker than IV
Name a beta blocker that can be given in a cocaine overdose
Labetalol – blocks alpha-1, beta-1 and beta-2
What form of metoprolol is indicated for CHF?
XL (oral)
Also comes IV and IR PO, but only XL is for CHF patients
What are some indications of propanolol?
Since propranolol is lipophilic and contains MSA, it can be used to treat many conditions including angina, a fib, tremor, hypertension, migraine, pheochromocytoma, AMI, aggression, anxiety, thyroid storm, portal hypertension…
Give an example of when to use sotalol
Atrial and ventricular arrhythmias, angina, hypertension – it is a nonselective beta blocker with antiarrhythmic activity
Which nonselective beta blocker is commonly used for open angle glaucoma?
Timolol
Describe the different functions of alpha-1 receptors on postsynaptic and presynaptic neurons
Postsynaptic – mediate vasoconstriction
Presynaptic – inhibit release of neurotransmitters
Which alpha-1 blockers are used to treat postural hypotension?
Doxazosin, prazosin, terazosin (all end in zosin)
Which alpha-1 blockers are bladder specific and used in BPH to increase urine flow?
Afluzosin, sildosin tamsulosin
List the only alpha-2 agonist that decreases blood pressure
Clonidine
Which alpha-2 agonist is commonly used for sedation in Neurosurgery?
Dexmedetomidine (Precedex)
Why does Precedex make a good sedative? (as opposed to Fentanyl or morphine)
Lipophilic, CNS specific, causes very little respiratory depression
Fentanyl and morphine require mechanical ventilation
What kind of medication is Sudafed and how does it work?
Alpha-1 agonist – vasoconstrict capillaries to relieve nasal congestion
What form of Sudafed is best for patients with hypertension?
Nasal spray – it is location specific
