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72 Cards in this Set
- Front
- Back
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What are the receptor preferences for
NE Epi |
NE: a1=a2>B1>>>>B2
Epi: B1=B2> a1=a2 Epi can enter CNS |
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DA role in SANS function
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-vasodilate renal arterioles
-positive inotropy found in chain ganglia and SIF for shock treatment |
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alpha 1 effects on :
vascular smooth mm eyes heart adipose |
vascular smooth mm-=> TPR
eye mydriasis, contract dilator heart=> mild,+ inotropy adipose=>GNG, glycogenolysis |
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alpha 1 effects on:
bladder trigon/sphincter ENS sphincter hair apocrine glands |
bladder trigon/sphincter-> contract/urrinary retention
ENS sphincter=> contract arrector pili mm=> erect hair apocrine glands=> sweating |
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alpha 1 R MOA
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GCPRs=> Gq=> increase IP3/DAG
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3 actions of alpha2 receptors and MOA
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a2--I AC=> decrease cAMP
autoreceptor reduces NE rleas heteroR reduces ACh + NEs Platelet aggregation |
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where is B 1 located, MOA, effects
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All B -->Gs=>A.C=>inc. cAMP
Heart: +ino/chrono/dromotropy JGA-> increase renin release |
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B2 effects
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Smooth muscle relaxation:
bronchioles arterioles in muscle (increase bloodflow to muscles) liver-> glycogenolysis |
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B3 effects
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Lipolysis
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what happens at low and high levels of SANS activation
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Low- release NE, a> B>>B2
Higher- Epi release-> fulll B1, B2 + a effects |
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the mechanism of homologous desensitization
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pharmacodynamic tolerance of the receptor to which agonist/ligand binds
GCPRKinase=> GCPR-P=> arrestins bind=>ligation with clathrin=> internalization |
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the mechanism of heterologous desensitization
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physiologic, agonist/ligand acts at its receptor to affect function of another=> PKC phosporylates other Receptor, altering sensitivity
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give an example of heterologous desensitization involving α-2
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α-2 stimulation reduces function of NET
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4 α-1 selective drugs
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Phenylephrine
pseudoephedrine midodrine methoxamine |
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Phenylephrine
MOA/ Effects/ clinical use |
competitive agonist for α1R
smooth mm contraction +other Decongestant hypertensive to reverse anesthetic hypotension priapism induce mydriasis for OPEN angle glaucoma |
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what are the cardiac/vascular effects of phenylephrine (a1)
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Hypotensive, vasocontrictor
little ino/chronotorpic effect, but HR decreases due to BaroR |
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Toxicity of Phenylephrine
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Hypertension toxicity (dissecting aneurism);
very high dose=> seizures |
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Uses of
Pseudoephedrine midodrine methoxamine |
pseudo- same as phenyl
midodrine- hypotension methoxamine- hypotension (like phenylephrine) |
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what are the 6 effector organs associated with α1R?
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iris radial muscle
all arterioles veins sphincters of gut trigone/sphincter of bladder sweat glands |
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4 α2 selective drugs
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clonidine
methyldopa guanfacine guanabenz |
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Clonidine
MOA effects |
competitive agonist at α2R
symmpatholytic effects REDUCES NE RELEASE IV/topical=>mild vasoconstr. oral=> mildly reduce SANS/NE; hypotensive |
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3 uses for clonidine
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~CNS effects: ADHD, opiate withdrawal anxiety
~antihypertensive ~sedative |
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toxic effects of clonidine
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orthostatic hypotension<-noNE
dizziness palpiations tachycardia HA/dprsn/LOA/ nasal congestion |
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what else does methyldopa do besides α2 agonist?
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aromatic animo acid decarboxalase inhibitor
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non selective B agonist
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isoproterenol
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Isoproterenol MOA/effects
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direct acting compeeptive B1,2,3 agonist
WAS used for asthma, but cardiac effects. |
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what are effects of B1 activation?
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-increased ino/chromo/dromotropy
-increased renin secretion |
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what are the effects of B2?
arterioles/veins trachial/bronchial mm gut tone/motility detrussor mm skeletal mm Liver |
arterioles/vv => dilate
trachial/bronchial mm=> relax gut tone/motility=> down detrussor mm=> relax skeletal mm=> contract/glycogenolysis/ K uptake Liver= GNG/glycogenolysis |
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4 B2 selective agonists
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albuterol
terbutatline metaproterenol pirbuterol |
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B2 agonists MOA
Albuterol |
smooth mm relaxation
Vasodilation from mm pooling=> baroR inc. HR |
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Toxicity of albuterol
when do effects start/end |
tolerance and decreased endogenous responsese
start 15 min- 4 hours |
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what is a nonspecific, direct acting adrenergic agonist
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Epinephrine
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epinephrine on BP
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over increase in HR with slight increase in pulse pressure
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what is an/ what do indirect acting adrenergic agonists do
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Amphetamine and the like
stimulate release of NE or inhibit its reuptake |
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MOA or aphetamine like drugs
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competitive re-uptake inhibitior
substrate for NET=DAT>SERT blocks MAO |
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Effects of amphetamine
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ca independent release of NE=DA> 5HT
increase HR, TPR, crosses BBB=> CNS effects |
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uses of amphetamine
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ADHD (imporved attention, reaction time, motor activity, anxiety, reduced appetite, inc. body temp/respiratory rate)
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Toxicity of amphetatmine
What is ceiling effect? |
death from uncontrolled metabolic acidosis with hyperthermia.
Ceiling effect: reduces Ca independent release |
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Other amphetamine like drugs
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ephedrine
pseudoephedrine- colds phenylpropanolamine phenmetrazine methylphenidate modafinil tyramine- aged foods |
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MOA of cocaine/like drugs
what is a caine property? Use? |
NE reuptake INH: Inhibits NET
bind to allosteric site on reuptake NET=DAT>>SERT Caine= local aneshtetic nasal surgeries |
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How is effect of cocaine unlike amphetamine
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alike except cocaine potentiateds the actions of NT that are released and cannot induce release by itself.
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toxicity of cocaine
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perforated septa (stimulant vasculitis)
HIgh: arrhythmias/seizures=> death |
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half life/ clearance of cocaine
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30minutes
cleared by liver detected in urine for several days |
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what are other cocaine-like durgs
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antidepresssants
atomoxetine: selective NE reuptake inhibitor to manage ADHD |
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use for non selective alpha blockers
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pheochromocytoma
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a1 selective drug
and effects |
prazosin
vascular blocking effect leading to orthostatic hypotension |
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a2 selective drug effects and representative drug
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Yohimbine
increase SANS activity during SANS activation (prevent negative feedback of relased NE normally acting on auto-receptors. Increase B tone and a1 tone |
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use for nonspecific B blockers
and 3 representative drugs |
hypertension
propanolol nadolol timolol |
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3 B1 blockers
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atenolol
metaprolol esmolol |
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phenoxybenzamine MOA
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COVALENT binding to a1>>a2
Blocks SANS activity when elevated (orthostatic HypoTN) NOT surmountable |
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Effects of phenoxybenzamine
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for pheochromocytoma
HR, CO increase through BaroR nasal stuffieness inhibition of ejaculation sedation (entry into CNS) Long acting (48 hours) |
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Triad of Symptoms for Pheochromocytoma
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episodic headhace
diaphoresis tachycardia catecholamine hypersecretion |
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phentolamine MOA
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reversible, competitive --I
less sedation than phenoxybenzamine GREATER blockade of a2=> greater cardiostimulation (less NE is blocked by a2 being activated=> less attenuation) |
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a1 selective antagonists Effects
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reduction in TPR. no reflex cardiac stimulation because 1 is blocked.
Manage HTN, used in BPH |
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what is an a2 selective antagonist?
what is it used for? |
Yohimbine
Blocking a2 will actually increase NE by blocking negative feedback which can act a1 and B receptors |
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What are B antagonist
uses |
BLOOD PRESSURE
ANGINA chf FOLLOWING INFARCTIONS GLAUCOMA LOCAL ANESHTHETIC EFFECTS |
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Propanolol
MOA Effects |
reduces beta tone and cardiac B1 effects:
Negative inotoropic/chronotropic effects Relief from angina reduce renin release --I B2 prevents mm vasodilation, bronchile relaxation, glycogenolysis in liver |
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what happens when B2 is blocked?
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prevents skeletal mm vasodilation
bronchiole relaxation, glycogenolysis |
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What does B1 blockade result in?
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negative inotropic, chronotropic
(Heart works less) TPR increases Reduces renin release |
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Uses for Propanolol
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decrease arrhythmias
angina migraine headage stage fright Sedation |
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Toxicity of Propanolol and B2 blockade
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~reductions in bronchiole tone
~reduces glucagon responsiveness in hypoglycemia masks tachycardia from hypoglycemia ~increased VLDL |
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Uses for TImolol
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nonselective, no anesthetic
~HTN ~ocular drops reduce pressure |
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3 Selective beta 1 blockers
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Metaprolol
atenolol esmolol |
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uses for metaprolol and atenolol
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negative chronotropy/inotropy
(angina) regulates dromotropy (arrhythmia) |
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Use for Esmolol
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ultrashort acting B1 blocker
ICU arrhythmias |
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what is a partial, non-specific agonist
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Pindolol
mildly reduce beta tone that is surmountable when SANS is high |
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Effects of Pindolol
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partial, nonspecific bagonist
~Px w heart disease ~reduce renin release ~ less hypotensive effects |
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prototypical mixed adrenergic antagonist
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Carvedilol
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Use of Carvedilol
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CHF (block both B and a1R)
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two NE depleting agents
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guanethidine and reserpine
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Guanethidine effects and MOA
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NE depletor
Ligand for NET and VMAT Enters vesicular pool and displaces NE=> functional SYMPATHECTOMY was used as hypertensive |
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Reserpine MOA
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~nonspecific VMAT inhibitor
~enters CNS ~ depletes NE, DA, 5HT centrally and peripherally ~functionalSYMPATHECTOMY=> antihypertensive |
