Ch. 19 Adrenergic blocking drugs Flashcards
What are the 3 classes of adrenergic blockers
alpha blockers, beta blockers, or alpha-beta blockers
What are the effects of alpha adrenergic blockers?
vasodilation
decreased BP
miosis (pupil constriction)
suppressed ejaculation
Which alpha blockers are used primarily for their vasoconstrictive properties?
ergot alkaloids
“ergo-“ prefix
Which alpha blockers are used as antihypertensives because they cause vasodilation?
drugs with suffix “-zosin”
Most alpha blockers are COMPETITIVE/NONCOMPETITIVE in their actions
competitive i.e. they compete with NEP for binding to the receptor
Explain the difference between competitive and noncompetitive alpha blockers
competitive: higher affinity for the receptor than NEP causes the receptor to be less responsive - reversible
noncompetitive: form a covalent bond with the receptor - irreversible
Which adrenergic blockers are also called oxytocics and why?
Ergot alkaloids - because they cause smooth muscle of uterus to contract and induce local vasoconstriction, which help control postpartum and postabortion bleeding
Which adrenergic blockers are used for treatment of BPH?
“zosin” drugs and tamsulosin
- relax smooth muscle of the prostate and bladder to reduce urinary obstruction
Explain how alpha blockers can prevent/control HTN in patients who have pheochromocytoma
pheochromocytoma is a tumor on the adrenal glands and secrete NEP –> SNS stimulation
the alpha blockers noncompetitively block exocrine glands
Which conditions with increased vasoconstriction can treated by the alpha blocker phentolamine?
Raynaud's disease acrocyanosis frostbite extravasation caused by vasopressors (NEP, EP, DA) because phentolamine causes vasodilation
Which of the following are CI’s for alpha blockers?
peripheral vascular disease liver and kidney disease CAD PUD sepsis
Beta 1 blockers are also called ____________
cardioselective beta blockers
cardioselective beta blockers cause what effects on the heart?
reduces HR
slows AV node conduction
prolongs SA node recovery
decreases myocardial oxygen demand by decreasing myocardial contractility
beta-2 adrenergic blockers cause what effects?
bronchiole constriction
vasoconstriction –> increased PVR –> increased BP
impaired insulin secretion from pancreas –> hyperglycemia
release of fatty acids from adipose tissue –> moderately elevated TG’s and reduced HDL’s
why are some beta blockers considered to have cardioprotective effects
they inhibit stimulation by catecholamines, (which are released during myocardial muscle damage and increase myocardial oxygen demand)