Sympathetics

Question 1

Albuterol, Salmeterol

Answer 1

Direct sympathomimetic

Beta2 > Beta1

Albuterol - acute asthma or COPD

Salmeterol - long term asthma or COPD control

Question 2

Dobutamine

Answer 2

Direct sympathomimetic

Beta1 > Beta2

Increase CO

Heart failure (inotropic > chronotropic)
Cardiac stress testing

Question 3

Dopamine

Answer 3

Direct sympathomimetic

D1 = D2 > Beta > alpha

Unstable bradycardia
HF
Shock

Lower dose - inotropic and chronotropic Beta effects

High dose - vasconstriction due to alpha effects

Question 4

Epinephrine

Answer 4

Direct sympathomimetic

Beta > alpha

Use:
Anaphylaxis
Asthma
Open angle glaucoma

Low doses - beta effects

High doses - alpha effects

Much stronger effects at Beta2 receptor than norepinephrine

Question 5

Fenoldopam

Answer 5

Direct sympathomimetic

D1

Postoperative hypertension
Hypertensive crisis
Vasodilator (coronary, peripheral, RENAL, and splanchnic)
Promotes natriuresis

Can cause hypotension and tachycardia

Question 6

Isoproterenol

Answer 6

Direct sympathomimetic

Beta1 = Beta2

Beta2 mediated vasodilation
dec. MAP and inc. HR through Beta1 reflex activity

Use: bronchospasm, cardiac arrest, heart block

Electrophysiologic evaluation of tachyarrhythmias

Can worsen ischemia

Question 7

Midodrine

Answer 7

Direct sympathomimetic

alpha1

Use:
Autonomic insufficiency
Postural hypotension
May exacerbate supine hypertension

Question 8

Norepinephrine

Answer 8

Direct sympathomimetic

alpha1 > alpha2 > Beta1

alpha1 mediated vasoconstriction –> Inc. MAP –> reflex bradycardia ; causes increase in systolic and diastolic pressures

Use:
Hypotension
Septic shock

Question 9

Phenylephrine

Answer 9

Direct sympathomimetic

alpha1 > alpha2

Use:
Hypotension (vasoconstrictor)
Ocular procedures (mydriatic)
Rhinitis (decongestant)

Question 10

Amphetamine

Answer 10

Indirect general agonist
reuptake inhibitor
releases stored catecholamines

Vasoconstriction
Increase CNS stimulation

Use:
Narcolepsy
Obesity
ADHD

Question 11

Cocaine

Answer 11

Indirect general agonist, reuptake inhibitor

Causes vasoconstriction and local anesthesia

Never give beta-blockers if cocaine intoxication is suspected (can lead to unopposed alpha1 activation and extreme hypertension.

Question 12

Ephedrine

Answer 12

Indirect general agonist
releases stored catecholamines

Vasoconstriction

Use:
Nasal decongestant
Urinary incontinence
Hypotension

Question 13

Clonidine, Guanfacine

Answer 13

alpha2 agonist

decrease sympathetic flow in CNS
vasodilation –> dec. TPR, dec. BP

Use:
Hypertensive urgency (limited situations)
ADHD
Touurette syndrome

Adv. Effects:
CNS depression
Bradycardia
Hypotension
Respiratory depression
Miosis

Question 14

Alpha-methyldopa

Answer 14

alpha2 agonist

Use:
Hypertension in pregnancy

Adv. Effects:
Direct Coombs + hemolysis
SLE-like syndrome

Question 15

Phenoxybenzamine

Answer 15

Irreversible (noncompetitive), nonselective alpha blocker

vasodilation —> dec. TPR

Use:
Pheochromocytoma (used preoperatively w/ beta blockers)
Prevent catecholamine (hypertensive) crisis

Adv. Effects:
Orthostatic hypotension
Reflex tachycardia

Question 16

Phentolamine

Answer 16

Reversible (competitive), nonselective alpha blocker

effects same as phenoxybenzamine

Use:
Give to patients on MAO inhibitors who eat tyramine-containing foods

Adv. Effects:
Orthostatic hypotension
Reflex tachycardia

Question 17

Prazosin, Terazosin, Doxazosin, Tamsulosin

Answer 17

Selective alpha1 blocker

Use:
Urinary symptoms of BPH
PTSD (Prazosin)
Hypertension (except Tamsolusin)

Adv. Effects:
First dose orthostatic hypotension - begin therapy at night
Dizziness
Headache

Question 18

Mirtazapine

Answer 18

Selective alpha2 blocker

Use:
Depression

Adv. Effects:
Sedation
Inc. serum cholesterol
Inc. appetite

Question 19

Beta-blockers

use + actions

Answer 19

Angina pectoris:
decrease HR and contractility (decrease O2 consumption)

MI:
decrease mortality

SVT: metoprolol, esmolol
decrease AV conduction velocity (class II antiarrhythmic)

Hypertension:
decrease CO, decrease renin secretion (due to B1-receptor blockade on JGA cells)

HF:
decrease mortality (bisoprolol, carvedilol, metoprolol)

Glaucoma: timolol
decrease secretion of aqueous humor

Variceal bleeding: nadolol, propranolol
decrease hepatic venous pressure gradient and portal hypertension

Question 20

Beta-blockers

Adv. effects

Answer 20

Erectile dysfunction
Cardiovascular adverse effects (bradycardia, AV block, HF)
CNS adverse effects (Seizures, sedation, sleep alterations)
Dyslipidemia (metoprolol)
Asthma/COPD exacerbations

Use with caution in cocaine users due to risk of unopposed alpha adrenergic receptor agonist activity

not contraindicated in diabetics due to risk of making hypoglycemia (benefits outweigh risks)

Question 21

Beta-blockers

B1 selective

Answer 21

Acebutolol (partial agonist)
Atenolol
Betaxolol
Esmolol
Metoroplol

preferred in ptns w/ COPD or asthma

Question 22

Beta-Blockers

nonselective B1 = B2 antagonists

Answer 22

Nadolol
Pindolol (partial agonist)
Propranolol
Timolol

Cause bronchoconstriction, peripheral vasospasm, and can predispose patients to hypoglycemia`

Question 23

Nonselective alpha and Beta antagonists

Answer 23

Carvedilol

Labetalol

Question 24

Nebivolol

Answer 24

combines cardiac-selective B1 adrenergic blockade with stimulation of B3 receptors, which activate nitric oxide synthase in the vasculature