Adrenergic Flashcards
Adrenergic neurons secrete what
Norinephrine
Presynaptic receptor controls the release of what?
Norepinephrine
Sns fight and flight responses
Mydrasis, increased cardiac output, bronchidilation, glycogen lysis, reduction in gi secretions/motility, relaxation of smooth muscle in urinary bladder, decreased blood flow for renal and mesenteric blood vessel construction, vasodilation to skeletal muscle, increased sweat, increase epinephrine from adrenal glands
What adrenergic receptors are passive
B 2/3
Catacholines in adrenergic
Epinephrine, dopamine, noriepinephrine, dopamine, isoproterenol, dobutamine
Noncatacholamines
Albuterol, phenylephrine, and ephedrine
Important difference between catacholamines and noncatacholamines
Catacholamines Low availability values when taken orally because they are quickly metabolized by intestinal and hepatic MAO AND COMT. They have short duration of action and half life
Non catacholamines
Due to absence of hydroxyl group noncatacholamines are less polar/more lipid soluble, and can pass the BBB and produce more central effects
Propanolol has had Significant ___________ metabolism
First pass
Methyl-tyrosine
Treatment of pheochromocytoma. It is a tumor of adrenal medulla that is associated with excessive production of catacholamines and development of severe hypertension
How to test for pheochromocytoma
24 hour urine to test for epinephrine levels
Generalized sympathomimetics means
Adrenergic agonists, non selective receptors
Generalized sympathomimetics med examples and MOA
Epi is alpha 1/2 and beta 1/2 which induces fight or flight.
Dopamine is d1, beta1 and alpha 1 agonist
What is epinephrine used for
Eye drops inducing dilation, bronchodilation for asthma patients, anaphylaxis,
What is dopamine used for
Cardiogenic shock on renal d1 receptor agonist that mediates mesenteric blood vessel vasodilation to increase renal blood flow, prevents renal failure.
How does affinity and dopamine relate to receptors
D1 highest affinity needs lowest dose to reach them, followed by b1, then alpha 1
Why does inhaled epinephrine used to treat asthma cause tachycardia
Because epinephrine is a non selective adrenergic agonist
Selective alpha adrenergic receptor sympathomimetics and MOA
Phenylephrine, tetrahydrozoline, and clonidine
Phenylephrine (used for vasoconstriction, nasal decongestant, treat priapism with prolonged responses to sildenafil (viagra) and tetrahydrozoline (what’s in visine to constrict blood vessels and make them not red ) are alpha 1 agonists
Clonidine passes bbb and acts as alpha 2 agonist which reduced release of catacholamines and sns tone. Acts as antihypertensive
Selective beta adrenergic receptor sympathomimetics examples and MOA
Isoproterenol - generalized beta 1/2 adrenergic receptor agonist
Dobutamine - selective beta 1 agonist
Albuterol and terbutaline- selective beta 2 agonist
Mirabegron- selective beta 3 agonist
Isoproterenol and dobutamine therapeutic affects
Cardiac stimulants, used in treatment of cardiac arrest and heart failure
Albuterol is a commonly used bronchodilator t/f
True
Terbutaline is used for
Used to reduce myometrial uterine contractions and prevent preterm birth.
Mirabegron
Activates beta3 on derisory muscles and serves as antispasmodic that is treatment of urinary incontinence
Indirect acting and mixed acting sympathomimetics example and MOA
Amphetamines are transported into the sympathetic axon terminal where is displaced catacholamines from internal stores. This effect results in release of NE into synapse indirect sympathomimetic
Ephedrine also displaces NE from internal stores (slow displacement) and is a weak a1/a2 agonist
Theatupetic effects of amphetamines
Cns stimulant used to treat narcolepsy, minimal brain disorders in the elderly.
Treatment of attention hyperactivity disorder (ADHD) adderall, methylphenidate (Ritalin), and dextromphetamine (Dexedrine) all classified as stimulants and enhance the release of norepinephrine, dopamine, and seretonin. Poorly understand because why does a stimulant help someone who’s already overstimulated relax and concentrate
Selective alpha adrenergic receptor sympathOLYTIC examples and MOA
Phentolamine- generalized alpha adrenergic receptor antagonist
Prazosin- selective a1 receptor antagonist
Tamulosin is selective a1 antagonist
Therapeutic effects of phentolamine, prazosin, and tamulosin
Phentolamine- treatment of frostbite and raynauds. Reduces cutaneous
vasoconstriction and increase blood flood to the skin
Prazosin- antihypertensive. Reduces peripheral vasoconstriction to renal and mesenteric vascular beds
Tamsulosin- used to treat urinary tract obstruction in men with BPH, Low doses relaxed smooth muscle in the prostate gland with minor effects on vascular smooth muscle cells
Selective beta adrenergic receptor sympathoLYTICS examples and MOA
Prononolol- generalized beta Adrenergic receptor antagonist
Metoprolol- selective b1 receptor antagonist
Therapeutic effects of propranolol and metoprolol
Propranolol- prophylactic treatment of migraine headaches that are associated with vasodilation.
Propranolol and metoprolol Can treat situation stress responses, palpitations, HTN, cardiac arrhythmias, ischemic heart disease, angina
How does the adverse effects of propranolol and metoprolol differ ?
Propanolol is non selective, metoprolol is selective
Combined alpha and beta sympathoLYTIC
example, therapeutic effect, and MOA
labetalol- alpha and beta antagonist, serves as antihypertensive medication that reduces cardiac output and blocks the compensatory vasomotor response by blocking alpha1 in the peripheral vascular system
Toxicology of adrenergic drugs
Sympathomimetics
Cns agitation, tremors, insomnia, hypertension, tachycardia , pressure headaches
Toxicology of adrenergic drugs
SympathoLYTICS
Orthostatic hypotension, fatigue, exercise intolerance, bronchoconstriction (especially with asthma and copds), Bradycardia that can lead to cardiac failure, cns depressiok
