Autonomics: Sympathomimetics

Question 1

Albuterol, salmeterol,

terbutaline

Answer 1

Direct sympathomimetic

MOA: β2 > β1

Clinical use: Albuterol for Acute asthma/COPD. Salmeterol
for Serial (long-term) asthma/COPD.
Terbutaline for acute bronchospasm in asthma
and tocolysis.

Question 2

dobutamine

Answer 2

Direct sympathomimetic

MOA: β1 > β2, α

Clinical use: Heart failure (HF), cardiogenic shock (inotropic
> chronotropic), cardiac stress testing.

Question 3

dopamine

Answer 3

Direct sympathomimetic

MOA: D1 = D2 > β > α

Clinical use: Unstable bradycardia, HF, shock; inotropic and
chronotropic effects at lower doses due to β
effects; vasoconstriction at high doses due to α
effects.

Question 4

epinephrine

Answer 4

Direct sympathomimetic

MOA: β > α

Clinical use: Anaphylaxis, asthma, open-angle glaucoma;
α effects predominate at high doses.
Significantly stronger effect at β2-receptor than
norepinephrine.

Question 5

fenoldopam

Answer 5

Direct sympathomimetic

MOA: D1

Clinical use: Postoperative hypertension, hypertensive crisis.
Vasodilator (coronary, peripheral, renal, and
splanchnic). Promotes natriuresis. Can cause
hypotension and tachycardia.

Question 6

isoproterenol

Answer 6

Direct sympathomimetic

MOA: β1 = β2

Clinical use: Electrophysiologic evaluation of
tachyarrhythmias. Can worsen ischemia.
Has negligible α effect.

Question 7

midodrine

Answer 7

Direct sympathomimetic

MOA: α1

Clinical use: Autonomic insufficiency and postural
hypotension. May exacerbate supine
hypertension

Question 8

mirabegron

Answer 8

Direct sympathomimetic

MOA: β3

Clinical use: Urinary urge incontinence or overactive bladder.

Question 9

norepinephrine

Answer 9

Direct sympathomimetic

MOA: α1 > α2 > β1

Clinical use: Hypotension, septic shock

Question 10

phenylephrine

Answer 10

Direct sympathomimetic

MOA: α1 > α2

Clinical use: Hypotension (vasoconstrictor), ocular procedures
(mydriatic), rhinitis (decongestant), ischemic
priapism.

Question 11

amphetamine

Answer 11

indirect sympathomimetic

MOA: Indirect general agonist, reuptake inhibitor, also
releases stored catecholamines

Clinical use: Narcolepsy, obesity, ADHD

Question 12

cocaine

Answer 12

indirect sympathomimetic

MOA: Indirect general agonist, reuptake inhibitor

Clinical use: Causes vasoconstriction and local anesthesia.
Caution when giving β-blockers if cocaine
intoxication is suspected (can lead to
unopposed α1 activation –> extreme
hypertension, coronary vasospasm).

Question 13

ephedrine

Answer 13

indirect sympathomimetic

MOA: Indirect general agonist, releases stored
catecholamines

Clinical use: Nasal decongestion (pseudoephedrine), urinary
incontinence, hypotension