Adrenergic Agonists Flashcards
Epinephrine at low doses activates what receptors?
B1 and B2. Causes increased HR ad CO, vasodilation. Increased systolic BP and decreased diastolic BP. Bronchodilation.
Epinephrine at high doses activates what receptors?
A1, A2, B1, B2. Net effect increase HR and CO, increase systolic and diastolic BP. Increase MAP and TPR from A1/A2 activation of vasoconstriction.
Epinephrine toxicity?
Arrhythmias, cerebral hemorrhage, pulmonary edema, anxiety
Norepinephrine physiological effects
Activates A1, A2, B1. Increase in CO due to increased contractility (B1). Increase in MAP (systolic and diastolic) due to A1 activation. Decrease in HR as a baroreceptor reflex response.
Norepinephrine toxicity
Ischemia
Norepinephrine indications?
Shock
Epinephrine indications?
Bronchospasm, anaphylaxis, cardiac arrest
Dopamine physiological effects at low doses?
Activate D1 and B1 receptors. Vasodilation in renal and splanchnic circulations (decrease in TPR due to D1 activation). Increase in HR and CO due to B1 activation.
Dopamine physiological effects at high doses?
Activates A1, A2, B1 receptors. Overall increase in MAP, TPR, and CO.
Dopamine toxicity at low and high doses?
Low dose toxicity: hypotension.
High dose toxicity: ischemia
Dopamine indications?
Cardiogenic shock
Isopreterenol physiological effects?
Nonselective Beta agonist. Activate B1 receptors to increase HR, CO, systolic BP. Activate B2 to cause vasodilation, decrease in TPR. Bronchodilation caused by B2 activation.
Isoproterenol Toxicity
Tachyarrhythmias
Isoproterenol Indications
Bradycardia or heart block when TPR is already too high
Isoproterenol Contraindications
Angina with arrhythmias