Pharmacology Exam 2: adrenergic agonists Flashcards

Terms Definitions
Sympathetic agonists are also called ____ or ___ ___.
- sympathomimetics - adrenergic agonists
various classifications of adrenergic agonists:
- catecholamine vs. non-catecholamine- direct vs. indirect acting- re-uptake inhibitors
you cannot take catecholamines orally.
Non-catecholamine adrenergic agonists are ___ lasting and __ be taken by mouth.
longercan
non-catecholamine alpha agonist:
phenylephrine
Beta 2 agonists:
- Albuterol- Ritodrine- Terbutalinebeta 2 agonists = art
Indirect acting sympathomimetics:
- Amphetamines- Tyramine
mixed acting sympathomimetics:
- ephedrine- pseudoephedrine
Topical vasoconstrictors:
- Naphazoline- Oxymetazoline- Tetrahydrozalinetopical vasoconstrictors= NOTthese are your nasal sprays
NE reuptake blockers:
- cocaine- impipramine
epinephrine stimulates ___ alpha and beta receptors.
all
Isoproterenol acts like a catecholamine is an agonist for __ _, _, and _ receptors.
- beta 1,2, and 3
Dopamine acts on what receptors:
alpha 1 beta 1 dopamine
Dobutamine acts like a catecholamine and is only an agonist for the ___ ___ receptors.
beta 1
amphetamines and tyramine can cause ___ release.
NE
the prototypic catecholamine is :
epinephrine
the prototypic noncatecholamine agonist is:
phenylephrine
prototypic beta 2 agonist is :
Albuterol
Prototypic indirect acting agonist:
tyramine
OTC indirect agonist:
pseudoephedrine
Oxymetazoline reuptake inhibitor:
cocaine
a direct mode of action means it acts on a ___.
receptor
An indirect mode of action means that it causes the release of ___ from nerve terminals.
NE
Mixed action drugs have both ___ and ___ effects.
direct and indirect
Alpha adrenergic effects:
1. constriction of blood vessels via alpha 1 (to lesser extend alpha 2)2. mydriasis via alpha 13. contraction of the spleen via alpha 14. contraction of the uterus via alpha15. inhibited release of insulin via alpha26.constriction of bladder sphincter alpha 17. Increased glycogenolysis in liver beta28. ejaculation, vas deferens alpha 19. relaxation of intestinal smooth muscle alpha 2
Beta adrenergic effects:
1. Heart: positive ionotropic and chronotropic effects beta 12. relaxation of bronchioles beta23. relaxation of uterus beta 24. relaxation of skeletal muscle arterioles beta 25. increased liver glycogenolysis, beta26. increased adipose tissue lipolysis beta37.increased releasae of insulin beta28.stimulate release of renin beta1
list the catecholamines:
- epinephrine- norepinephrine- dopamine- dobutamine- isoproterenol
Epinephrine is more potent for __ than __ receptors. But clinically, when given at therapeutic doses we see ___ are affected. The concept of __ __ requires knowledge of which receptor response will prevail.
- beta than alpha- both- net effect
epinephrine effects on the heart:
Via beta 1 receptors: - positive inotropic effect (contractility)- positive chronotropic effect (rate)- increased automaticity (sa node depolarizes more quickly): latent pacemakers become active= increased ectropic beats, arrhythmias may result b/c refractory period is reduced after an ap- increased conduction rate in the AV node
ultimately epinephrine causes the ___ __ to __ and the __ of ___ to increase, so ___ ___ is ___. Thus ___ consumption ____.
- heart rate to increase- force of contraction to increase- cardiac output is increased- oxygen consumption is increased
On skeletal muscle arterioles there are ___ _ and ___ __ receptors. At physiological quantities of epinephrine, the ___ receptors are acted on and we see ____. At pharmacologic doses ___ receptors are acted on and we see ____.
- beta 2 and alpha 1- physiological> beta 2> vasodilation- pharmacological> alpha 1> vasoconstriction
Veins have only __ _ receptors so they can only ____ in response to increased sympathetic stimulation.
- only alpha 1- constrict
coronary blood vessels ___ in response to epinephrine b/c of ___ _ receptors.
dilatebeta 2
Kidney, skin, and mucosal blood vessels ___ in response to epineprhine b/c of ___ _ receptors.
vasoconstrictalpha 1
cerebral blood vessels remain unchanged in presence of epinephrine
Net effect of epinephrine on blood pressure and cardiac function depends on:
- dose- circulatory status- compensatory reflexes- baroreceptors are stretch receptors in carotid sinus and aortic arches that sense blood pressure changes and maintain homeostasis
When baroreceptors sense a change in bp, signals are transmitted to the ___ center in the __ ___to alter parasympathetic and sympathetic outflow to the heart and blood vessels.
- vasomotor- brain stem
If baroreceptors sense a sudden increase in bp, sympathetic tone will be ___ and ___ tone to the ___ node will be ___.
- sympathetic tone will decrease- vagal tone to SA node will increase
If baroreceptors sense a sudden drop in bp, symp tone will ___ and parasymp tone will ___.
increasedecrease
metabolic effects of epinephrine:
- calorigenic and tremor effects in skeletal muscle via beta 2 - increased glycogenolysis (beta 2)- increased lipolysis (beta 3)
Clinical uses of epinephrine:
1. Bronchial asthma2. Anaphylactic shock3. Infiltration with local anesthetics4. Cardiac resuscitation5. Topical for hemostasis
how does epinephrine treat bronchial asthma:
. Administered by inhalation. Bronchodilation (2) and inhibition of antigen-induced histamine release.
How does epinephrine treat anaphylactic shock?
(give IV or SC) Improves breathing by same mechanisms as in 1 above, plus increases blood pressure and reverses edema (1).
epinephrine reverses edema by __ _ receptors
alpha 1
Anaphylaxis is an ___ phenomenon. Three things occur all related to the dump of histamine. list these 3 things.
1. Bronchoconstriction2. profound vasodilation so bp drops3. edemaEpinephrine (epi pen) is ideal treatment for this. Epinephrine is a physiolgical antagonist b/c it diates brochioles (beta 2 effect), raises bp (alpha 1 affect), and edema comes out of venules so epinephrine stops any additional edema from forming and allows present edema to be rid by lymphatics.
Lidacane anesthetic injected with epinephrine at dentist, without the epinephrine the lidacaine could be deathly. Epinephrine constricts the vessels and keeps the lidacaine in the specific area. Epinephrine acts on alpha 1 and beta 2 receptors, but alpha
Adverse effects of epinephrine:
1. arrhythmias (beta 1 effects)2. cerebral hemorrhage (alpha 1 effects)3. necrosis distal to site of injection4. CNS effects: anxiety, headache
Contraindications for epinephrine:
1. Hypertension2. Shock3. Hyperthyroidism4. Angina pectoris5. Degenerative heart disease don't have to memorize these, its just used in emergency situations
Contraindications for epinephrine:
1. Hypertension2. Shock3. Hyperthyroidism4. Angina pectoris5. Degenerative heart disease don't have to memorize these, its just used in emergency situations
Norepinephrine or ____ is selective for __ _, __ _, and __ _ receptors. What are its pharmacological effects?
- Levophed- alpha 1- alpha 2- beta 1pharmocologic effects: 1. Heart beta 1 direct effects (iontropic and choriontropic effects)2. Vasculature: alpha 1 > vasoconstriction which activates the baroreceptors
NE has no beta 2 affects so not used for anaphylactic shock. NE is much shorter acting than epinephrine, so not used to control blood pressure.
Net effect of NE:
- positive inotropic effects but reflex bradycardia with increased systolic and diastolic blood pressures
E widens the pulse pressure because it stimulates 2 receptor on arterioles, causing vasodilationBecause E at this dose does not raise mean blood pressure, no vagal reflexes are activatedContrast these effects of those of NE, which essentially has no st
with a low dose of epinephrine you would see the diastolic pressure ___ b/c of __ __ receptors causing ___ ___. You would see the systolic pressure would be ___ b/c of the increased contractility and ejection fraction via ___ _ recptor effects. Thus with
- decreasing - beta 2 - arteriole dilation- increasing- beta 1- widened pulse pressure- no change in mean arterial pressure
Isoproterenol has pure ___ effects so it would ___ diastolic pressure even more than epi did, and it would increase contractility even more than epi did so systolic is more increased. So ultimately mean bp ___ a little bit and ___ __ is increased.
- beta- decrease- decrease- heart rate
w/o parasympathetic input the heart rate would be around:
90bpm
NE increases pulse pressure via the ___ _ receptor b/c diastolic did not decrease b/c NE does not have ___ action, so you see ___ _ effect of ___. This increased bp is sensed by the barorecptors which in turn causes heart rate to ____. So NE is telling th
alpha 1beta 2alpha 1 effect of vasoconstrictiondecreaseparasympathetics
inject NE hos is pulse rate, blood pressure, and peripheral resistance affected?
- peripheral resistance increases- blood pressure increases- pulse rate decreases
inject epi, how is peripheral resistance, blood pressure, and heart rate affected?
- peripheral resistance decreases (at low doses)- blood pressure stays same- heart rate increases
inject isoproterenol how is peripherial resistance, blood pressure, and heart rate affected?
- peripheral resistance decreases- blood pressure decreases a little- heart rate increases
LOW DOSES OF EPINEPHRINE> FILL BETA 2 RECEPTORS (DECREASED BP), HIGH DOSES FILL ALPHA RECEPTORS (INCREASED BP)
Isoproterenol (Isuprel)
1 and 2 stimulant. (no alpha effects).Pharmacological effects:1. Heart: Positive inotropic and chronotropic effect. 2. Vasculature: Vasodilatation of skeletal muscle arterioles (2 receptors on arterioles).
Isoproterenol: Clinical Uses
Relatively limited because of intense cardiac effects. 1. Bronchial asthma (Aerosol)2. Heart block. (give by IV. catheter.)Side effects Common: tachycardia, flushing, headache, rapid pounding heart. Serious: arrhythmias, angina
notice that isoproterenol, a pure beta1/beta2 agonist, has a greater ____ effect than E. This is because E is both a beta2 agonist and also an alpha 1 agonist. For E, The alpha 1 effects partly offset the beta2 effects at this dose. Indeed, if the dose of
- vasodilation
Epi is more potent for __ _ receptors but more efficacious at __ _ receptors.
- more potent at beta 2s- more efficacious at alpha 1s
Dopamine aka ___ is an agonist at __ receptors and cause ___ in the kidneys. This is also a ___ _ agonist which leads to ___ ___ __. It is also an __ _ agonist which can lead to ___ (less potent here than others though).
- Intropin- D1- vasodilation- beta 1- increased cardiac output- alpha 1- vasoconstriction
Intropin is :
dopamine
Levophed is :
norepinephrine
adrenalline is:
epinephrine
dopamine is a precursor to ___ in all ___ neurons.
norepinephrinenorepinephrine
Shock basically means you have inadequate ___ __, the cardinal sign of shock is ___ ___ __.
inadequate cardiac outputlow blood pressure
If we lose a lot of blood, flow to many organs will stop except for these three:
- heart- brain- kidneyof these 3, the kidneys give up blood flow first
With shock, the sympathetic is so activated that blood is not getting to the kidneys.
main use for dopamine:
- shock, especially hypovolemic shock- beta 1 effects benefit cardiac output- alpha 1 effects increase blood pressure- D1 effects vasodilate the kidney arterioles, leading to better maintenance of blood flow
Duration of catecholamines is not very long, it has to be given via IV infusion or it will me metabolized very quickly.
Direct acting non-catecholamines are ___ ___, lacking the ___ moeity. They are analogues for NE and Epi.
synthetic agentscatechol
Non-catecholamines are longer acting and are metabolized more slowly, why?
- they are not acted upon as readily by MAO as catecholamines are- they are not stored in vesicles
some direct acting non-catecholamines are effective p.o.
An alpha adrenergic agonist is ___ aka _____. It acts on the __ _ receptors and causes ___ and __ ___ __. But you can expect ___ ___.
- Phenylephrine aka Neosynephrine- alpha 1- vasconstriction- increased blood pressure- reflex bradycardia
___ is used in decongestant cold meds orally and topically.
Phenylephrine aka Neosynephrine
Phenylephrine uses:
1. Nasal decongestant2. Infiltration with local anesthetics (more likely is the use of metaraminol).3. Pressor agent to maintain bp4. Ocular examination. Mydriasis without affecting accommodation.
Beta-2 Selective Adrenergic Agonists are __ to __ times more potent at beta 2 than at beta 1, thus they are more selective for ___ muscle over __ muscle. This is longer acting than ____. Tolerance may develop.
- 5 to 10 so its affinity is 100 times greater- smooth over cardiac- longer acting than catecholamines
primary use of beta 2 selective antagonists:
obstructive lung disease: asthma and COPD
Tolerance develops with beta 2 selective agonists b/c the beta receptor is a __ __ coupled receptor. When these are over activated, they ___ which is a form of ___ ___. this is a problem when asthmatics overuse their inhalers.
- g-coupled- internalize- down regulate
Tolerance develops with beta 2 selective agonists b/c the beta receptor is a __ __ coupled receptor. When these are over activated, they ___ which is a form of ___ ___. this is a problem when asthmatics overuse their inhalers.
- g-coupled- internalize- down regulate
Beta 2 adrenergic agonists used to treat bronchial asthma:
1. Albuterol (Proventil); Levo-albuterol (Xopinex)2. Metaproterenol (Metaprel, Alupent)3. Terbutaline(Brethine)(aerosol and sc; sc for emergency tx of astma; only 2 agent available sc ) iv.and p.o. to delay delivery. 4. Isoetherine (Bronkosol)5. Salmeterol (Serevent). Once a day agent for chronic but not acute treatment of asthma. Has slow onset of actionA Manly Tone Is Sexy.
Salmeterol lasts longer and was used for quite some time, but last spring it was in advair inhalers (beta 2 long acting affects and the other was topical corticosteroid to slow down inflammation) but FDA said not good for kids>unexpeced cardiac effects (b
beta 2 agonists used to treat bronchial asthma:
A Manly Tale Is Sexy. AlbuterolMetaproterenolTerbutalineIsotherineSalmeterol
Albuterol beta 2 agonist should be in __ form for acute treatment and ___ for chronic treatment of bronchial asthma.
- aerosol- p.o.
side effects caused by the oral route of albuterol:
hypotension (beta 2) , muscle tremors (beta 2), tachycardia (beta 1), hypokalemia. Effects on blood glucose are variable.
Ritodrine is a ___ __ __ agonist used to ___ ___.
alpha 2 adrenergic agonistdelay labor
beta 2 adrenergic agonist side effects:
- skeletal muscle tremors b/c beta 2 receptors on muscle increase energy productin
Indirect Acting Sympathomimetics:
TyramineAmphetaminemany others
Tyramine has the potential to cause a hypertensive crisis in pts on ___ inhibitors.
MAO inhibitors
Tyramine is found in many foods (red wine, aged cheeses, peanuts). It normally has huge first pass effect by ___ by the gut and liver that it never enters circulation. But if person on ___, then can cause ___ __.
- monoamine oxidase- MAOI- hypertensive crisis
tyramine is a ___ __. if it gets into nerve terminals it causes release of ___ .
decarboxylated tyrosinenorepinephrine
Pseudoephedrine:
Naturally occurring in genus EphedraThere are four isomers; two of these, ephedrine and psuedoephedrine are clinically effective. Mechanism: indirect (releases NE). Relatively insensitive to degradation by MAO and COMT. Effective p.o.
pseudoephedrine used to be used orally as decongestant but much less now.
clincial uses of pseudoephedrine:
nasal & eustachian tube decongestantReleases NE – decongestant because of reduced pooling of blood in the venous circulationOrally activeDoes not penetrate CNS significantly – much less dependence potential than ephedrine. Nonetheless, access is now greatly restricted (easy to synthesize methamphetamine from this starting chemical).
pseudoephedrine works as a nasal decongestant b/c it causes release of ___ which reduces ____ ___ in __ circulation.
- NE- reduces blood pooling- venous
pseudephedrine not used much now, b/c easy to make meth from it.
common OTC products with direct and indirect alpha 1 effects:
Naphazoline (Privine)Tetrahyrolazine (Tyzine, Visine)- reduces eye rednessXylometrazoline (Otrivin)Oxymetazoline(Afrin)
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