Beta Blockers Flashcards
Differentiate selective from non-selective beta blockers.
Selective: block only beta-1
Non-selective: block both beta-1 and beta-2
What is ISA in relation to beta blockers?
ISA = intrinsic sympathomimetic activity. Some beta blockers have some mild beta agonist properties. They still have more beta antagonist effects but the are less potent beta antagonists.
What is MSA in relation to beta blockers?
MSA = membrane stabilizing activity. These beta blockers also inhibit fast sodium channels
What is the risk of beta blockers with MSA and when are they used?
Risk: prolonged QT - dysrhythmias
Use: eye drops for glaucoma - less stinging in eyes
What is the most commonly prescribed beta blocker containing ISA?
pindolol
List some examples of beta blockers that are renally cleared and hapeatically cleared.
renally (hydrophilic): atenolol
hepatically (lipohilic): carvedilol, labetalol
What is the benefit of beta blockers that have alpha-1 antagonism and give some examples.
More potent beta blockers s/p vasodilation - useful in cocaine OD. Exs: carvbedilol, labetalol
What is the advantage of beta blockers that release nitric oxide?
More potent beta blockers s/p vasodilation
Give two examples of commonly used beta-1 selective beta blockers.
atenolol and metoprolol
What happens to selective beta blockers at high doses?
They lose selectivity
Explain why patients on beta blockers must have them withdrawn slowly over a relatively long period of time.
While on beta blockers, the heart upregulates beta 1 receptors and increases their sensitivity. Sudden withdrawal of the medication can lead to tachycardia and hypertension.
What is the effect of beta blockers on lipid panels?
Worsens lipid panel - esp non-selective BBs.
What is the effect of beta blocker medications on patients with heart failure?
Benefit bc of a decrease in HR which inc filling time.
Down side is BBs have a negative inotropic effect.
List three other cautions for people taking beta blocker medications.
May cause fatigue, depression, and sexual dysfunction. Effect worsens with lipiphilicity of BB, especially propranolol.
What are the indications for atenolol?
AMI, angina, HTN, migraine prophylaxis
What is unique about the pharmacodynamics of carvedilol?
Non-selective beta blocker with some alpha-1 blockade (IE, some vasodilation)
What are the indications for carvedilol?
HTN, portal HTN, A-fib, CHF (mortality dec shown)
What is unique about the pharmacokinetics of esmolol?
It is eliminated via plasma esterases (in blood), meaning the drug will have a short 1/2 life and can only be given IV.
What are the indications for esmolol?
intra- and post-op HTN, A-fib, aortic dissection
What 3 beta blockers are used for CHF?
Carvedilol, Metoprolol XL, Bisoprolol
What is unique about the pharmacodynamics of labetalol?
Nonselective beta blocker that also has alpha-1 blockade (more alpha-1 than carvedilol)
What is the primary use for labetalol?
HTN emergency
What is unique about the pharmacodynamics of nebivolol?
Selective beta blocker with that stimulates some NO release?
What are the indications for nebivolol?
HTN, migraine prophylaxis
