Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
27 Cards in this Set
- Front
- Back
|
Beta 1 stimulation of the heart results in
|
increased rate and force of contraction
|
|
|
Beta 1 stimulation of the kidney results in
|
renin secretion
|
|
|
Beta 1 stimulation of fat results in
|
lipolysis
|
|
|
Beta 2 stimulation of lungs results in
|
bronchodilation
|
|
|
Beta 2 stimulation of bladder results in
|
relaxation
|
|
|
Beta 2 stimulation of the eye's ciliary muscle results in
|
relaxation
|
|
|
Beta 2 stimulation of blood vessels in skeletal muscle results in
|
slight vasodilation
|
|
|
Alpha 1 stimulation in vascular smooth muscle results in
|
contraction
|
|
|
Alpha 1 stimulation in urinary bladder/sphincter results in
|
contraction
|
|
|
Alpha 1 stimulation in prostate results in
|
contraction
|
|
|
What are the two main therapeutic uses of alpha adrenergic antagonists?
|
lower blood pressure
decrease urinary symptoms of benign prostatic hypertrophy (BPH) |
|
|
How do alpha adrenergic blockers work?
|
1) Reversible (competitive) inhibition
most, including phentolamine and prazosin 2) Irreversible inhibition phenoxybenzamine |
|
|
Which alpha adrenergic blocker causes irreversible inhibition?
|
Phenoxybenzamine
|
|
|
What are the subtypes of alpha adrenergic antagonists?
|
Non-selective/not highly selective
Alpha 1 selective Alpha 2 selective |
|
|
Alpha 1A receptors are located mostly in
|
prostate and bladder neck
|
|
|
Alpha 1 Receptor anatgonists cause what effects?
|
CARDIOVASCULAR
inhibition of vasoconstriction induced by endogenous catecholamines and vasodilation may occur in both arteriolar resistance vessels and veins => fall in BP due to decreased peripheral resistance Magnitude depends on activity of sympathetic nervous system: more affect when upright Fall in BP opposed by baroreceptors reflexes => increase in heart rate and CO and fluid retention Effect exaggerated if alpha 2 also blocked in peripheral symp. nerve endings => enhanced NE release and increased stimulation of Beta 1 in heart OTHER EFFECTS reduction in smooth muscle tone in prostate and neck of bladder => decreased resistance to urine outflow in BPH |
|
|
Alpha 1B receptors are found mostly in
|
vascular smooth muscle
|
|
|
Alpha 2 antagonists cause
|
Selective alpha 2 (yohimbine) can increase smpathetic outflow and release of NE from nerve endings => activation of alpha1 and beta1 receptors in heart and peripheral vasculature => increase in BP
can increase increase penile blood inflow and decrease blood outflow in erectile dysfunction |
|
|
Phenoxybenzamine
|
Alpha Receptor Anatgonist: Non-selective/not highly selective
Major effect: blockage of alpha receptors in smooth muscle => vasodilation => decreased BP AND decreased peripheral resistance => increased CO (from reflex sympathetic nerve stimulation AND alpha 2 blockade => further increase heart rate => reflex tachycardia Use of drug severely limited by alpha 2 blockade effects. Irreversible binding to alpha receptor (up to a week!) Used for: Pheochromocytoma--tumors of adrenal medulla and sympathetic neurons to counteract catecholamines Adverse Effects: Postural hypertension Reflex Tachycardia Inhibition of ejaculation |
|
|
Phentolamine
|
Alpha Receptor Anatgonist: Non-selective/not highly selective
can also block serotonin, histamine from mast cells, and blocks K+ channels IV only; similar effects to phenoxybenzamine: blockage of alpha receptors in smooth muscle => vasodilation => decreased BP Uses: pheochromocytomas (adrenal medulla tumor) Adverse Effects: Postural hypertension Reflex Tachycardia GI Stimulation/abdominal pain/exacerbate peptic ulcer |
|
|
Alpha 1 receptor blockers are unique because they
|
highly select (1000-fold) for alpha 1 over alpha 2
|
|
|
Alpha 1D receptors are found mostly in
|
bladder
|
|
|
Doxazosin
|
Alpha Receptor Antagonist: Alpha 1 Selective
Major effects from blockade of alpha 1 in arterioles and veins => leads to decreased PVR and venous return to heart; no increase in HR; decreases cardiac preload Relaxation of urinary bladder trigone and sphincter => increases urine outflow Apoptotic properties in prostate smooth muscle cells Use for hypertension and BPH Dose: once daily at bedtime Metabolism: low dose with hepatic dysfunction Adverse Effects: Marked postural hypotension Dizziness Sexual dysfunction--impotence |
|
|
Prazosin
|
Alpha Receptor Antagonist: Alpha 1 Selective
Major effects from blockade of alpha 1 in arterioles and veins => leads to decreased PVR and venous return to heart; no increase in HR; decreases cardiac preload Relaxation of urinary bladder trigone and sphincter => increases urine outflow Apoptotic properties in prostate smooth muscle cells Use for hypertension Dose: once daily at bedtime Metabolism: low dose with hepatic dysfunction Adverse Effects: Marked postural hypotension Dizziness Sexual dysfunction--impotence |
|
|
Terazosin
|
Alpha Receptor Antagonist: Alpha 1 Selective
Major effects from blockade of alpha 1 in arterioles and veins => leads to decreased PVR and venous return to heart; no increase in HR; decreases cardiac preload Relaxation of urinary bladder trigone and sphincter => increases urine outflow Apoptotic properties in prostate smooth muscle cells Use for hypertension and BPH Dose: once daily at bedtime Metabolism: low dose with hepatic dysfunction Adverse Effects: Marked postural hypotension Dizziness Sexual dysfunction--impotence |
|
|
Alfuzosin
|
Alpha Receptor Antagonist: Alpha 1 Selective
Major effects from blockade of alpha 1 in arterioles and veins => leads to decreased PVR and venous return to heart; no increase in HR; decreases cardiac preload Relaxation of urinary bladder trigone and sphincter => increases urine outflow Apoptotic properties in prostate smooth muscle cells Use for BPH (functional uroselective since it distributes in prostate relative to serum) Dose: take immediately after the same meal every day Metabolism: low dose with hepatic dysfunction Adverse Effects: Marked postural hypotension Dizziness Sexual dysfunction--impotence |
|
|
Tamulosin
|
Alpha Receptor Antagonist: Alpha 1 Selective
Major effects from blockade of alpha 1 in arterioles and veins => leads to decreased PVR and venous return to heart; no increase in HR; decreases cardiac preload Relaxation of urinary bladder trigone and sphincter => increases urine outflow Apoptotic properties in prostate smooth muscle cells Use for BPH (uroselective) Dose: once daily at bedtime Metabolism: low dose with hepatic dysfunction Adverse Effects: Marked postural hypotension Dizziness Sexual dysfunction--impotence and impaired ejaculation Orthostasis (postural hypotension) |
