Pharm: Adrenergics

Question 1

Epinephrine

Answer 1

Mechanism: alpha1 agonism (vasoconstriction) at high doses, beta1 agonism (increased HR and contractility) at low doses, beta2 agonism (bronchodilation, mild decrease in BP)
Use: cardiac arrest, severe HTN, bronchospasm in asthma and anaphylaxis
SE: HTN, arrhythmia, MI, pulmonary edema, headache, anxiety

Question 2

Norepinephrine

Answer 2

Mechanism: alpha1 agonism (vasoconstriction), beta1 agonism (increased contractility)
Use: increases BP in treatment of severe hypotension and shock
SE: angina, MI, arrhythmia, decrease RPF

Question 3

Dopamine

Answer 3

Mechanism: alpha1 agonism (vasoconstriction) at high doses, beta agonism (increased HR and contractility) and D1 (increased renal perfusion) agonism at low doses
Use: increases BP in treatment of severe hypotension and shock
SE: angina, arrhythmia, HTN, nausea

Question 4

Dobutamine

Answer 4

Mechanism: beta1 agonism > increases HR and contractility > increases CO; alpha1 and beta2 effects are weak and produce mild vasodilation
Use: cardiogenic shock (pressor), cardiac stress testing
SE: arrhythmia, angina, hypotension, headache

Question 5

Ephedrine, pseudoephedrine

Answer 5

Mechanism: stimulates release of NE and epinephrine > increases BP, increases CO, induces bronchodilation, stimulates CNS (amphetamine effects)
Use: nasal decongestant
SE: HTN, tremor, anxiety, arrhythmia

Question 6

Cocaine

Answer 6

Mechanism: blocks Na/K ATPase, blocks presynaptic monoamine reuptake pumps (like DAT1) responsible for reuptake of NE, serotonin, and dopamine, thereby potentiating their effects
Use: local anesthesia
SE: HTN, paranoia, seizures, cardiac ischemia and infarction, arrythmia, addiction

Question 7

Phenylephrine

Answer 7

Mechanism: alpha1 agonism > vasoconstriction (decreased mucosal secretions) and pupil dilation
Use: severe hypotension and shock, nasal congestion, mydriasis in eye exam
SE: arrhythmia, headache

Question 8

Clonidine

Answer 8

Mechanism: alpha2 agonism in the vasomotor centers of the medulla > decreased release of NE and other NTs > decreased central adrenergic activity > decreased vasoconstriction, HR, CO
Use: HTN; useful in pts with renal disease because it does not decrease RPF
SE: rebound HTN, bradycardia, sedation

Question 9

Isoproterenol

Answer 9

Mechanism: beta1 and beta2 agonism > increases HR and contractility, causes vasodilation and bronchodilation
Use: torsades de pointes (co-administer Mg), cardiac arrest, heart block
SE: tachyarrhythmias, anxiety, pulmonary edema

Question 10

Albuterol, pirbuterol, bitolterol

Answer 10

Mechanism: beta2 agonism > bronchodilation; can also cause intracellular movement of K
Use: asthma, hyperkalemia (in high doses)
SE: tachycardia, tremor, aniety

Question 11

Metoprolol, atenolol, esmolol, acebutolol

Answer 11

Mechanism: selective beta1 antagonism > decreases HR and contractility; minimal beta2 antagonism
Use: HTN, tachycardia, CAD
SE: mild bronchoconstriction (avoid in asthmatics), bradycardia, impotence, hypotension

Question 12

Carvedilol, labetalol

Answer 12

Mechanism: alpha1 receptor blocker + beta blocker > decreases HR and contractility, vasodilation, bronchoconstriction
Use: CHF, HTN
SE: dizziness, hypotension, bradycardia

Question 13

Propanolol, nadolol, pindolol, timolol

Answer 13

Mechanism: nonselective beta antagonism > decreased HR and contractility, decreased BP, bronchoconstriction
Use: HTN, CAD, hyperthyroidism-induced tachycardia, chronic migraines
SE: bronchoconstriction, arrhythmia, impotence, fasting hypoglycemia, hypotension

Question 14

Prazosin, terazosin, doxazosin, tamsulosin, alfuzosin

Answer 14

Mechanism: selective alpha1 antagonist > vasodilation and decreased BP; decreases prostatic neck contraction to improve urinary flow
Use: HTN, BPH
SE: first-dose syncope, orthostatic hypotension, dizziness, nasal congestion

Question 15

Phenoxybenzamine

Answer 15

Mechanism: irreversible alpha antagonist > decreases BP
Use: pheochromocytoma (esp. prior to surgical resection)
SE: orthostatic hypotension, tachycardia, nasal congestion

Question 16

Methyldopa

Answer 16

Mechanism: alpha2 agonist that acts in the vasomotor centers of the medulla > decreases release of NE and other NTs > decreases vasoconstriction
Use: moderate HTN; useful in pts with renal disease because it does not decrease RPF
SE: sedation, dizziness, positive Coombs test, orthostatic hypotension

Question 17

Terbutaline, ritodrine

Answer 17

Mechanism: beta2 agonist > relaxation of smooth muscle in lungs (bronchodilation) and uterus (reduces contractions)
Use: delay preterm labor, status asthmaticus
SE: dizziness, tachycardia, anxiety, chest pain, tremor