Catecholamines Flashcards
Epi class
endogenous catecholamine that is nonselective adrenergic agonist
Epi MOA
binds to alpha1/2 and b1/2 receptors equally- activating g coupled protein receptors to increase cAMP causing an influx of intracellular Ca2+ causing agonist effects
Epi se
tachycardia, angina, arrhythmias, HTN, decrease RBF, vasoconstriction of- skin, Gi tract, muscle, liver and kidneys. gangrene in digits, hypoglycemia
Epi ci
caution in DM, hyperthyroid, pheochromocytoma, glaucoma, caution in pregnancy. Decrease LA absorption. avoid in peripheral LA blocks in fingers and toes
Epi PK
Onset 1-2 min DOA 5-10 min E1/2t 30 sec Small vd= poor lipid solubility reuptake or diffusion primary way drug gets out of system then metabolized by Catechol-o-methyltransferase (COMT) and monoamine oxidase enzymes biotransformations in blood, liver, kidneys
Metabolites Excreted in urine
epi dose
anaphylaxis- 0.1-1mg. 1mg q3-5min for CV arrest ACLS, 1-2mcg/min beta2 (asthma); 4-5mcg/min beta1 (poor co), 10-20mcg/min alpha and beta
NE/Levophed class
direct acting endogenous catecholamine and adrenergic agonist- sympathomimetic
NE MOA
binds to alpha 1 and 2 receptors and b1- lacks B2 and activates g coupled protein receptors to increase cAMP causing an influx of Ca2+ causing an agonist effect and increase contractility; potent vasoconstrictor; when it increase BP= causes baroreceptor activation and drops HR and increase SVR preserves coronary and cerebral BF in decrease BP; decrease venous return- CO and HR; low dose causes increase HR/CO; alpha at high doses
NE Pk
onset rapid; DOA 5-10min; E1/2 2.5min; reuptake or diffusion primary way metabolized then by MAO and COMT. excreted in urine
NE SE
increase SBP, DDBP, MAP; decreases HR bc baroreceptor activation, decrease RBF, HBF and splanchnic BF; organ ischemia and necrosis of extremities and digits
NE CI
pheochromocytoma, caution in liver and renal disease; MAOi’s and TCAs, hypovolemai, thrombosis
NE dose
4-16mcg/min IV
Dopamine class
dopamine/adrenergic agonist; sympathomimetic endogenous precursor of NE Preg class C
DA MOA
stimulates all adrenrgic receptors including DA receptors. extracted from L-dopa on catecholamine synthesis of tyrosine; small doses- DA effects- vasodilation by stimulation of adenyl cyclase-> increasing level of cAMP in vascular SM (renal, coronary and mesenteric beds); medium doses= beta causing increased myocardial contraction and increase HR; large doses= alpha and beta effects causing vasoconstriction of all vascular beds including renal increasing BP, CO, SVR; also increase endogenous NE release (doesn’t work well with decreased catecholamine stores)
DA PK
Does not cross BBB, onset rapid, DOA 5-10min; E1/2 2 min; metabolized and elimated by MAO and COMP to 75% inactive and 25%NE. Must protect from light
DA SE
tachycardia, arrhythmias, angina, extravasation, N/V, increased IOP and UOP, widen qrs
DA CI
right HF, pheochromocytoma, thyroid storm, IOP, caution in CAD/post MI, sulfa allergy. Should not be used with methyldopa, non selective bb, tcas, and MAOIs
synergistic with Dobutamine to decrease SVR and increase CO (Da dilates cutaneous vascular beds while Dobutamine dilates other vascular beds)
DA dose
DA1- low dose 1-3mcg/kg/min ( increase GFR, RBF, UOP); beta 1 medium dose 3-10 mcg/kg/min; alpha large dose 10mcg/kg/min
Dobutamine class
sympathomimetic; synthetic catecholamine-synthetic analog of isoproterenol
Dobutamine MOA
beta 1 selective agonist and weak beta 2 and alpha 1; binds to receptor and activates G protein receptors in increase cAMP causing an influx of Ca2+= increase contractility and CO without increase HR or Bp too much (good for CHF)
Dobutamine PK
onset 1-2 min; DOA 5-10min, e1/2 2 min, metabolized and eliminated by MAO and COMT reuptake or diffusion away from active site
Dobutamine SE
minimal increase HR (weak activity at SA node), arrhythmias, angina, HTN, platelet inhibition, thrombocytompenia, coronary artery and pulmonary vasodilator, N, phlebitis
Dobutamine CI
avoid in hypertrophic cardiomyopathy, MAOis, TCAs, caution in CAD and MI (ok for CHF); not good if need an increased SVR
Dobutamine dose
Typical dose 2-10mcg/kg/min; (max is 40)
Beta15mcg/kg/min
