Adrenergic Antagonists Flashcards
List the conditions that are most commonly treated with B-blockers. What is the mechanism by which B-blockers produce their beneficial effects?
use: HTN, (angina, arrhythmia) mechanisms - cardioselective (B1 blockers) - nonselective (B1 and B2 blockers) - partial agonists (B1 and B2 agonists)
Identify the 6 beta-adrenergic antagonists and the commonly recognized category of beta-blockers to which they belong.
NONSELECTIVE
- propranolol
- timolol
- nadolol
CARDIOSELECTIVE
- atenolol
- metoprolol
PARTIAL AGONISTS
- pindolol
Describe how toxic side effects of the beta antagonist drugs differ with their receptor subtype selectivity.
NONSELECTIVE
- bronchospasm
- symptoms of hypoglycemia
- raise triglycerides
- bradycardia
CARDIOSELECTIVE (B1)
- hypotension
- bradycardia
- mild, transient
PARTIAL AGONISTS
- same as non-selective
List the 5 prominent alpha-adrenergic antagonists. Identify the following for each:
- receptor subtype selectivity
- conditions they are used for
NON-SELECTIVE
- phenoxybenzamine (irreversible)
- phentolamine (reversible)
=> USE: HTN in relation to perioperative tx of pheochromocytoma, dermal necrosis, vasoconstrictor extravasation
A1 SELECTIVE - prazosin - doxazosin - terazosin => USE: HTN, benign prostatic hyperplasia
List the most serious side effects produced by selective and non-selective alpha-adrenergic receptor antagonists.
NONSELECTIVE: prolonged hypotension, reflex tachycardia
SELECTIVE A1: orthostatic hypotension
Explain why selective alpha-1-adrenergic receptor antagonists are more preferable for use in hypertension than non-selective alpha-adrenergic receptor antagonists.
because there is less cardiac stimulation b/c A2 functions are preserved
Describe the following for non-selective beta antagonists:
- drug names
- effects
- use
- toxicity
- contraindications
NAMES: propranolol, nadolol, timolol
EFFECTS
- reduced heart rate and contractility
- reduced renin release
- reduced vasoconstriction
- bronchiole constriction in patients with asthma or COPD
USE
- HTN
- angina
- glaucoma
- heart failure
- arrhythmia
TOXICITY
- bronchospasm
- hypoglycemia
- increased triglycerides
- bradycardia
CONTRAINDICATIONS
- side effects in patients with respiratory diseases
- asthma
- sinus bradycardia
- heart block
- cardiogenic shock
Describe the following for cardioselective beta antagonists:
- drug names
- effects
- use
- toxicity
- contraindications
NAME: atenolol, metoprolol, esmolol (reduced respiratory side effects)
EFFECT
- reduced heart rate and contractility
- reduced renin release
USE
- HTN
- angina
- arrhythmia (only esmolol; only transient b/c short half-life)
TOXICITY
- mild, transient
- hypotension
- bradycardia
CONTRAINDICATIONS
- sinus bradycardia
- heart block
- cardiogenic shock
Describe the following for partial beta agonists:
- drug names
- effects
- use
- toxicity
- contraindications
NAME: pindolol
EFFECT
- reduced heart rate and contractility
- reduced renin release
- reduced vasoconstriction
- bronchiole constriction in patients with asthma or COPD
USE
- when HTN is due to sympathetic output
- in those less tolerant of bradycardia
- in those with less tolerance for exercise
TOXICITY
- less bradycardic effect
- bronchospasm
- hypoglycemia
- increased triglycerides
CONTRAINDICATION
- asthma
- sinus bradycardia
- heart block
- cardiogenic shock
If you have a patient with respiratory disease, what beta blocker category would you recommend?
cardioselective: atenolol, esmolol, metoprolol
non-selective and partial agonists will still have respiratory issue
If you have a patient that has bradycardia, which beta blocker category would you recommend?
- partial agonists b/c have less bradycardic effect
If you have a patient with high sympathetic output, which beta blocker category would you recommend?
- partial agonists b/c block high output
Describe the following for non-selective alpha antagonists:
- drug names
- effects
- use
- toxicity
- contraindications
NAMES
- phenoxybenzamine
- phentolamine
EFFECTS
- inhibit vasoconstriction
- block presynaptic A2 receptor => increased NT release => increased ionotropy and cronotropy => increased CO and contractility
- vasodilation
USE
- HTN associated with perioperative pheochromocytoma
- dermal necrosis
- vasoconstrictor extravasation
TOXICITY
- prolonged hypotension
- reflex tachycardia
CONTRAINDICATIONS
- CAD
Describe the following for selective A1 antagonists:
- drug names
- effects
- use
- toxicity
- contraindications
NAME
- prazosin
- doxazocin
- terazocin
EFFECTS
- inhibit vasoconstriction
- preserves A2 function
USE
- HTN
- benign prostatic hyperplasia
TOXICITY
- orthostatic hypOtension
CONTRAINDICATIONS
