Synethetic Catecholamines Flashcards
Dobutamine Class
Synthetic catecholamine, selective beta 1 adrenergic agonist
Dobutamine MOA
Synthetic analog of isoproterenol
Acts on B1, G proteins to increase cAMP, influx of Ca causing increased contractility & CO
Some B2 (vasodilation, decrease SVR) & A1 (minimum)
Dobutamine Uses (3)
Cardiogenic and septic shock
Treat mild CHF
Cardiac stress tests
Dobutamine Dose
Infusion: 2 to 20 mcg/kg/min
Dobutamine Onset and DOA
Onset: 1 minute
DOA: 10 minutes
Dobutamine Metabolism
MAO, COMT
Dobutamine Excretion
Renally excreted
Dobutamine Admin Considerations
Caution in patients with tachycardia, CAD, hypertrophic cardiomyopathy
Decrease SVR, platelet inhibition
Phenylephrine Class
Selective Alpha 1 adrenergic agonist
Phenylephrine MOA
Agonizes A1 receptors, triggering a G protein response to ⬆️ cAMP -> ⬆️ Ca, resulting in ⬆️ BP
Phenylephrine Uses (2)
Vasodilatory shock
Hypotension (with a normal heart rate) s/p spinal anesthesia
Phenylephrine Dosing
Small boluses of 40-80 mcg
Infusion: 20 – 50 mcg/min
Phenylephrine Onset and DOA
Onset: 1 minutes
DOA: 15 minutes
Phenylephrine Metabolism
MAO
Phenylephrine Excretion
Renally excreted
Phenylephrine Admin Considerations
Reflex bradycardia mediated by the vagus nerve can reduce cardiac output
Caution in patients with bradycardia, hyperthyroidism, pheochromocytoma
Phenylephrinemust be diluted from a 1% solution (10 mg/1-mL ampule), usually to a 100 mcg/mL solution and titrated to effect
Vasopressin Class
Exogenous antidiuretic peptide & vasopressor
Vasopressin MOA
Agonizes vasopressin receptors.
V1: constriction of vascular smooth muscle
V2: in DCT & collecting ducts of kidneys = increased water reabsorption
Vasopressin Uses (3)
Septic shock
Post–cardiopulmonary bypass shock state
ACE Inhibitor related hypotension