Sympathomimetics Flashcards Preview

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Flashcards in Sympathomimetics Deck (41):
1

Sympathetic organ synapse

involves post ganglionic neuron synapsing directly at the target organ; kidneys release dopamine (vasodilation), sweat glands release ACH (thermoregulation)

2

two major types of sympathetics receptors

alpha and beta, different roles at different sites in the body

3

Mimetics also called

adrenergic agonists

4

lytics also called

adrenergic antagonists

5

Mimetics role

increase release of neurotransmitters, block reuptake into the presynaptic neuron, decrease metabolism

6

Lytics

decrease neurotransmitter release, deplete vesicular stores, decrease synthesis of neurotransmitters

7

3 types of adrenergic neurotransmitters

dopamine, epinephrine, norepinephrine; all very different, commercially available and regularly used, have to give continuously

8

baroreceptor reflex

when baroreceptors sense increase in BP, will try to turn off sympathetic and turn on parasympathetic with M2 receptors

9

Dopamine

works as an agonist on dopamine receptors, all have B activity, a vasopressor; dose dependent causes range of responses

10

Norepinephrine (levophed)

agonist at a1, a2, B1, very little B2, a pressor; a1=vasoconstriction and increase in BP; B1 *net effect decreases HR

11

Norepinephrine (levophed)

agonist at a1, a2, B1, very little B2, "best" pressor; a1=vasoconstriction and increase in BP; B1 *net effect decreases HR

12

longest time any pt is on Norepinephrine

12 days, try to take off drug as soon as stabilized

13

ADRs of norepinephrine

arrhthmies, bradycardia, peripheral ischemia, HA

14

Epinephrine

Most non-selective, works on all adrenergic receptors, a1=vasoconstriction, B2=vasodilation in skeletal muscle, a and B cancel out with potential for small increase in BP; B1 increases HR

15

Uses of epinephrine

used with local anesthesia to capitalize on vasoconstriction to keep local; anaphylaxis, bronchodilator, symptomatic bradycardia, asystole, VT

16

ADRs of epinephrine

chest pain, arrythmia, flushing, hypertension, tachycardia, anxiety

17

Phenylephrine (neo-synephrine)

a1 agonist, hypotension, no direct effects on heart; increase BP and peripheral vasoconstriction will trigger baroreceptor reflex and decrease HR; slows tachycardia

18

uses of Phenylephrine (neo-synephrine)

nasal decongestant, spray or red eyes, drops; also used as decongestant, sudafed; use 3 days and stop or effects will decrease

19

Rebound congestion

repeated topical exposure to a* agonist results in receptor desensitization, increase dose to get effects and increase again

20

Isoproterenol is considered a B agonist because

it requires very large doses to activate alpha receptors

21

Pressors should be infused via

a central line

22

Practical consideration of pressors

receptor site selectivity is dose dependent, limb threatening in severe case of estravasation, continuous monitoring required,often required during surgery to balance anesthesia

23

a2 agonists uses and medication

used for HTN and muscle spasticity; clonidine (catapres), Methlydopa (aldomet), Tizanidine (zananex), guantacine (tanex)

24

a2 agonists uses and medication

used for HTN and muscle spasticity; clonidine (catapres), Methlydopa (aldomet), Tizanidine (zananex), guantacine (tanex)

25

Clonidine (catapres)

most common alpha agonist, PO and transdermal, HTN, also ADHD, narcotic withdrawal, severe pain, migraine; ADR drowsiness, HA, fatigue, constipation, dry mouth, bradycardia

26

Methyldopa (aldomet)

HTN, limited to HTN in pregnancy, ADR: dizziness, HA, sedation, impotence, hemolytic anemia

27

Tizanidine (zanaflex)

muscle relaxor, avoid with hepatic, ADR: hypotension, sedation, dry mouth: DI cipro, fluvoxamine, works faster on empty stomach; old, cheap

28

Guanfacine (tenax)

PO, never for hypertension, ADHD, ADRs: drowsiness, dizziness, HA,, dry mouth, many drug interactions

29

B agonist, non-selective

isoprterenol (isuprel)

30

B agonist, B1 selective

Dobutamine, dopamine

31

B agonist, B2 selective

terbutaline, albuterol, levalbuterol, salmeterol, formoterol, vilanterol

32

Isoproterenol (Isuprel)

relax bronchial, GI and uterine, increase HR and contractility, peripheral vasodilation, IV continuous, limited use; ADR angina, tachyarrhythmia

33

Isoproterenol (Isuprel)

relax bronchial, GI and uterine, increase HR and contractility, peripheral vasodilation, IV continuous, limited use; ADR angina, tachyarrhythmia

34

Dobutamine (dobutrex)

Dopamine derivative, strong B1, weak B2, increase force of contraction, not a pressor, give IV contiuous, most common for CHF; ADR: hypotension, tachycardia

35

Terbutaline (Brethine)

B2 agonist, relax bronchial and uterine muscle, asthma, *terminate premature contraction, short term only; ADR: bronchospasm, nervousness, trembling

36

Albuterol (Proventil, Ventolin, Proair)

B2 agonist, bronchodilation, tablet, syrup nebulizer, and inhaler; doesn't cause cardio effect; minimal ADR; only emergent DOC; onset 1-2 min, lasts 3-4 hours

37

Levalbuterol (Xopenex)

cleaner version of albuterol (only L-isomer); reduces ADR? better bronchiolar B2 affinity? inhaler and nebulizer, controversial; onset 5-10 min, lasts 3-6 hours

38

Salmeterol (serevent)

B2 agonist, long acting, respiratory disease, long duration, chronic management, not for emergency; onset 30-48 min lasts 12 hours

39

Formoterol (Foradil)

B2 agonist, long acting, respiratory disease, long duration, chronic management, not for emergency; onset 3 min, lasts 10-14 hours

40

Vilanterol

B2 agonist, long acting, respiratory disease, long duration, chronic management, not for emergency

41

Aformoterol (brovana)

B2 agonist, long acting, respiratory disease, long duration, chronic management, not for emergency; onset 7-20 min, lasts 26 hours