Adrenergics Flashcards
What is the signal transduction pathway for beta receptors
Accumulate cAMP and activate PKA
What is the signal transduction pathway for alpha 2 receptors
Decrease cAMP and inhibit PKA
What are the three mechanisms of action for indirect acting adrenergic drugs?
Reuptake blocker (cocaine), MAO inhibitor (selegine, phenelzine), and releasing agents (Amphetamines, methylphenidate)
What alpha adrenergic agonists prefer a1>a2?
phenylephrine, methoxamine
What alpha adrenergic agonists prefer a2>a1
Clonidine, methyNE
What is the receptor selectivity for NE
a1=a2; B1>B2
What is the receptor selectivity for epinephrine?
a1=a2; B1=B2
What beta adrenergic agonists prefer B1>B2
Dobutamine
What Beta adrenergic agonists select both B R equally
isoproterenol
What Beta adrenergic agonists prefer B2»B1
Albuterol, terbutaline, ritodrine
What Dopamine agonists prefer D1 & D2 equally
dopamine
What dopamine receptor agonists prefer D1»D2
Fenoldopam
What are the effects of epinephrine and the corresponding receptor?
Cardiac function - B1 - increase HR, contractility
Vascular tone - B2, a1 - inc systolic BP, same MAP
Respiratory - B2 - relax s. m. - a1 - dec secretion, congestion
skeletal m - B2 - tremor, inc K uptake
Elevate Blood Glucose - B2- inc liver glycogenolysis - a2/B2 - inhibit insulin release
Increase blood FFA - B
Increase renin release - B1
What are the effects of NE and the corresponding receptor
Cardiac stimulation - B1 - pump harder but dec HR
Potent vasoconstriction - a1
Why does NE decrease HR
The rise in BP is detected by the baroreceptors, which tell the hard to pump slower
What are the effects of dopamine and what are the corresponding receptors
vasodilation of the renal, cerebral, mesenteric, coronary a. - D1
Activation presynaptic D2 - suppress NE release
What is the signal transduction pathway for alpha 1 R
IP3, DAG, MAPK, PI3K,
These stimulate cell growth
What is the effects of phenylephrine
a1>a2. mydriasis (pupillary dilation), decongestion, severe vasoconstriction (inc BP)
What happens to phenylephrine is you block the baroreflex
The drug is 10x more potent on vasoconstriction
What are the effects of clonidine
a2>a1. Central effect on the a2 receptors in the brainstem, which decreases NE output –> lower BP and HR
What are the effects of isoproterenol
B1=B2. Increase cardiac output (B1), vasodilation / bronchodilation (B2). Therefore keeping BP about the same
What are the effects of dobutamine
B1>B2. Increase cardiac output
What are the effects of terbutaline, albuterol
B2>B1. Bronchodilation, relax uterus
Are indirect adreneric agonists polar or nonpolar
nonpolar
What adrenergic agonist should be used to treat hypotensive emergencies?
Ne, phenylephrine, methoxamine
What adrenergive agonist should be used to treat chronic HTN
ephedrine
What adrenergic agonist should be used to treat cardiogenic shock (massive acute MI)
dopamine, dobutamine
What adrenergic agonist should be used to treat CHF
dopamine
What adrenergic agonist should be used to manage HTN
any a2 agonist
What adrenergic agonist should be used to treat HTN emergencies
fenoldopam
What adrenergic agonist should be used to treat complete AV block and cardiac arrest
Epinephrine, isoproterenol
What adrenergic agonist should be used to treat decongestion
Phenylephrine, ephedrine, pseudoephedrine
What adrenergic agonists should be used to treat bronchial asthma
albuterol, terbutaline
What adrenergic agonist should be used to treat anaphylaxis
epinephrine
What adrenergic agonist should be used to induce mydriasis
phenylephrine
What adrenergic agonist should be used to treat glaucoma
apraclonidine, brimonidine
What adrenergic agonist should be used to suppress premature labor
terbutaline
What adrenergic agonist should be sued to treat stress incontinence
Ephedrine
What adrenergic agonist should be used to Tx priapism
phenylephrine
What adrenergic agonist should be used to tx narcolepsy
amphetamines, methylphenidate
What adrenergic agonist should be used to treat ADHD
methylphenidate
What adrenergic agonist should be used to tx obesity
Phentermine, ephedrine, amphetamines
What are the CV adverse effects of adrenergic agonists
Inc BP, Inc cardiac work, sinus tachycardia
What are the CNS adverse effects of adrenergic agonists
Amphetamines - insomnia, dec appetite, anxiety, psychoses
cocaine - convulsions, arrhythmias, hemorrhagic stroke
What indirect antiandrenergics deplete NE
reserpine, guanethidine
What indirect antiadrenergics inhibit NE synthesis
metyrosine
What indirect antiadrenergics activate inhibitory a2 Receptors
Clonidine
What indirect antiadrenergics are used to treat chronic HTN
guanethidine, clonidine
What indirect antiadrenergic is used to treat a pheochromocytoma
metyrosine
What are the nonselective alpha R antagonists
Phentolamine (competitive), phenoxybenzamine (noncompetitive)
What are the alpha 1 receptor specific antagonists
-osin’s
what are the mixed alpha receptor antagonists
labetalol, carvedilol
What are the non selective B antagonists
propanolol (A), pindolol (pa), nadolol (a), penbutolol (pa)
What are the B1 selective antagonists
metoprolol (ia), betaxolol (a), acebutolol (pa), atenolol (a)
What is the difference when using phentolamine and prazosin to cause cardiac stimulation
Phentolamine (nonselective a) will cause a larger increase in B1 effect because there is no negative feedback on NE release (a2 job)
Prazosin has no tachycardia
What alpha antagonists are used to treat pheochromocytoma
phentolamine, phenoxybenzamine
What alpha antagonists are used to treat chronic HTN
-osin
What alpha antagonists are used to treat ED
phentolamine, papverine
What alpha antagonists are used to treat BPH
tamsulin, silodosin
these specifically target a1a R
What are the adverse effects of alpha R antagonists
postural Hypotension, increase HR, salt/water retention, impaired ejaculation, nasal stuffiness
What are the effects of B blockers
inhibit renin release, inc respiratory secretion, decrease intraocular pressure, tx hyperthyroidism, tx HTN, tx angina pectoris, MI, arrhythmias, HF
What are the adverse effects of B blockers
CNS - sedation, depression, sleep disturbances
Resp - inc resistance, can trigger bronchospasm
dec HDL/LDL ration
May delay recovery from insulin induced hypoglycemia
