Adrenergic Agonists

Question 1

Epinephrine

Answer 1

Class: Sympathetic Agonist

Action: alpha and beta adrenergic agonist (beta effects more pronounce, although dose related)

Indications: cardiac arrest, symptomatic bradycardia, normovolemic hypotension, allergies/anaphylaxis, severe bronchospasm

Contraindications: few in emergency setting

Doses: 0.3-1.0 mg

Routes: IV, IO, IM, SQ, ET, inhaled

Adverse Effects: palpitations, anxiety, tremulousness, headache, dizziness, hypertension, can worsen cardiac ischemia

Other: two preparations are commonly available: 1:1000 (1mg/mL) and 1:10,000 (1mg/10mL)

Question 2

Norepinephrine: Levophed

Answer 2

Class: Sympathetic Agonist

Action: alpha and beta adrenergic agonist (alpha effects are more pronounced)

Indications: normovolemic hypotension, septic shock, cardiogenic shock

Contraindications: should not be used in hypovolemia until volume replacement has occurred

Doses: 0.1-0.5 mcg/kg/min (titrate to effect)

Routes: IV

Adverse Effects: palpitations, anxiety, tremulousness, headache, dizziness, hypertension, can worsen cardiac ischemia, reflex bradycardia

Other: extravasation can cause localized tissue damage, best administered through a central line

Question 3

Dopamine: Intropin

Answer 3

Class: Sympathetic Agonist

Action: alpha and beta adrenergic agonist

Indications: normovolemic hypotension, symptomatic bradycardia, septic shock, cardiogenic shock

Contraindications: should not be used in hypovolemia until volume replacement has occurred

Doses: 2-20 mcg/kg/min (titrated to effect)

Routes: IV

Adverse Effects: palpitations, anxiety, tremulousness, headache, dizziness, hypertension, can worsen cardiac ischemia, reflex bradycardia

Other: extravasation can cause localized tissue damage, best administered through a central line, proposed renal benefit has been disproved

Question 4

Dobutamine: Dobutrex

Answer 4

Class: Synthetic Sympathetic Agonist

Action: alpha and beta adrenergic agonist (inotropic properties more pronounced than chronotropic properties)

Indications: congestive heart failure

Contraindications: should not be used in hypovolemia until volume replacement has occurred

Doses: 2-20 mcg/kg/min (titrate to effect)

Routes: IV

Adverse Effects: palpitations, anxiety, tremulousness, headache, dizziness, hypertension, can worsen cardiac ischemia, reflex bradycardia

Other: extravasation can cause localized tissue damage, best administered through a central line, other agents preferred in cardiogenic shock

Question 5

Phenylephrine: Neo-Synephrine

Answer 5

Class: Sympathetic Agonist

Action: almost a pure alpha agonist causing vasoconstriction

Indications: normovolemic hypotension, septic shock, spinal shock

Contraindications: avoid use in cardiogenic shock

Doses: 100-180 mcg/min (0.5-2.0 mcg/kg/min and titrate to effect)

Routes: IV

Adverse Effects: palpitations, anxiety, tremulousness, headache, dizziness, can worse cardiac ischemia, reflex bradycardia

Other: can be applied topically to nasal mucosa to shrink tissues prior to nasal procedures