Adrenergic Antagonists Flashcards
What are the three non selective Beta blockers?
Propranolol
Timolol
Nadolol
What are the two cardioselective Beta blockers?
Atenolol
Metoprolol
What is a partial agonist of B1 and B2 receptors?
Pindolol
How do all beta blockers affect the heart?
They decrease heart rate and force of contraction. (Note: partial agonist pindolol’s bradycardic response is limited).
How do nonselective Beta blockers affect peripheral resistance?
They block B2 receptors, so they decrease vasodilation and increase peripheral resistance. There is unopposed vasoconstriction by A1 receptors.
How do cardioselective Beta blockers affect peripheral resistance?
They have no effect because they do not block B2 receptors.
How does partial agonist pindolol affect peripheral resistance?
Slight decrease due to partial B2 activation
How do all beta blockers affect renin release?
They all decrease renin release because they all decrease B1 activation.
How do nonselective Beta blockers affect bronchioles?
They cause bronchoconstriction due to their blocking of B2 receptors. You should NEVER give a beta blocker to an asthmatic patient!
How do cardioselective beta blockers affect bronchioles?
Little bronchoconstriction because cardioselective beta blockers only block B1 receptors. Still not recommended in asthmatics.
How does partial agonist pindolol affect bronchioles?
Some bronchodilation, but asthmatics have a reduced capacity to dilate bronchioles.
How do nonselective beta blockers affect glucose metabolism?
Reduced hyperglycemic response ot epinephrine. Use caution with these drugs in diabetics because they can mask symptoms of hypoglycemia.
How to cardioselective beta blockers affect glucose metabolism?
Little effect
How does partial agonist pindolol affect glucose metabolism?
Reduced response to epinephrine because partial agonist activity is not as potent as endogenously released epinephrine
What are the physiological effects of non selective beta blockers? (Propranalol, Nadolol, Timolol)
Decreased HR Decreased renin release Decreased contractility Reduced sympathetic activation Inhibition of aqueous humor production
What are the indications of nonselective beta blocker usage?
Hypertension Angina Glaucoma Early-moderate heart failure Arrhythmia Thyrotoxicosis Anxiety
Toxicity of nonselective beta blockers?
Bronchospasm
Mask symptoms of hypoglycemia
Bradycardia
Contraindications of nonselective beta blockers?
Bronchospasm during asthma
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic Shock
Cardioselective Beta blockers physiological effects?
Decrease HR
Decrease contractility
Decrease renin release
Decrease sympathetic activation
Cardioselective Beta blockers toxicity?
Hypotension
Bradycardia
Cardioselective Beta blockers Indications?
Hypertension
Angina
Arrhythmia
Cardioselective Beta blockers Contraindications?
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic shock
Severe heart failure
Partial agonist pindolol physiological effects?
Decrease BP
Decrease contractility
Decrease renin release
Decreased sympathetic activation
Partial agonist pindolol indications?
Hypertension
Partial agonist pindolol toxicity?
Hypotension
Dizziness
Depression
Insomnia
Partial agonist pindolol Contraindications?
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic Shock
Severe heart failure
What are the nonselective alpha blockers? Which ones are reversible or irreversible?
Phentolamine (reversible)
Phenoxybenzamine (irreversible)
Phentolamine and Phenoxybenzamine physiological effects?
Decreased BP
Increased chronotropy and inotropy (large increase in HR)
Phentolamine and Phenoxybenzamine Indications?
Hypertension associated with pheochromocytoma
Vasoconstrictor-induced extravasation
Phentolamine and Phenoxybenzamine Toxicity?
Prolonged hypotension
Reflex tachycardia
What are the selective alpha-1 adrenergic blockers?
Prazosin
Doxazosin
Terazosin
Selective alpha-1 antagonist physiological effects?
Inhibit vasoconstriction
Prostate smooth muscle relaxation
Selective alpha-1 antagonist Indications?
Hypertension
Benign prostatic hyperplasia
Selective alpha-1 antagonist toxicity?
Orthostatic hypotension
Syncope
(These drugs are not prescribed to the elderly because they may increase risk of falls)
