Adrenergic Antagonists Flashcards
What are the types of adrenergic antagonists?
- Non-Selective (β1 and β2)
- Cardioselective (β1)
- Partial Agonist (β1 and β2)
What are the non-selective β blockers?
Propranolol, nadolol, timolol
What are the effects of propranolol, nadolol and timolol?
Decreased HR
Decreased contractility
Decreased renin release
Reduced sympathetic activation Inhibition of aqueous humor production
Propranolol, nadolol, timolol indication
Hypertension Angina Glaucoma Heart failure Arrhythmia
Propranolol, nadolol, timolol Toxicity
Bronchospasm
Mask symptoms of hypoglycemia
Bradycardia
Propranolol, nadolol, timolol Contraindications
Bronchospasm during asthma
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic Shock
What are cardioselective β1-blockers?
Metoprolol, atenolol, esmolol
What are the effects of metoprolol, atenolol, esmolol?
Decrease HR
Decrease contractility
Decrease renin release
Decreased sympathetic activation
LIMITED effect on respiratory system
Metoprolol, atenolol, esmolol indication
Hypertension (metoprolol, atenolol),
Angina (metoprolol, atenolol)
Arrhythmia
Metoprolol, atenolol, esmolol Toxicity
Depression
Insomnia
Hypotension
Bradycardia
Metoprolol, atenolol, esmolol Contraindication
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic Shock
What is the half life of esmolol like?
Esmolol has very short half-life ~9 mins
What is a partial agonist of β1 and β2?
Pindolol
What is the effect of pindolol?
Decrease BP
Decrease contractility
Decrease renin release
Decreased sympathetic activation
Pindolol indication
Hypertension in those who are less tolerant of bradycardia and reduced exercise capacity caused by other beta blockers without partial agonist activity
Pindolol Toxicity
Same as for non-selected beta blockers
Bronchospasm
Mask symptoms of hypoglycemia
Bradycardia
Pindolol Contraindications
Bronchospasm during asthma
Sinus bradycardia
2nd and 3rd degree heart block
Cardiogenic Shock
What non-selective α-receptor antagonists?
Phenoxybenazmine (irreversible)
Phentolamine (reversible)
What are the effects of phenoxybenzamine an phentolamine?
Decreased BP by inhibiting vasoconstriction
Increased chronotropy and inotropy due to blockade of pre-synaptic α2-receptor
Phenoxybenzamine indication
Hypertension associated with perioperative treatment of pheochromocytoma, test for pheochromocytoma
Phentolamine indication
Dermal necrosis and sloughing with vasoconstrictor extravasation
Phenoxybenzamine an phentolamine Toxicity
Prolonged hypotension
Reflex tachycardia
Nasal Congestion
Phenoxybenzamine an phentolamine Contraindications
Coronary Artery Disease
What are the selective α1-receptor blockers?
Prazosin, doxazosin, and terazosin
What are the effects of prazosin, doxazosin, and terazosin?
Inhibit vasoconstriction, resulting in vasodilation and decreased BP
Prostate muscle relaxation
What is unique about the effect of prazosin, doxasin and terazosin on the heart?
They give less cardiac stimulation than non-selective α-blockers due to preservation of α2- adrenergic function
Prazosin, doxazosin, and terazosin indication
Hypertension
Benign prostatic hyperplasia (BPH)
Prazosin, doxazosin, and terazosin Toxicity
Syncopy
Orthostatic hypotension
