Alters physiology. These are very simple answers to a complex question. Levophed (norepinephrine) increases blood pressure; Dopamine increases heart rate, blood pressure and cardiac function (contractility); Dobutamine increases cardiac contractility and heart rate.
Pressors & inotropes. Levophed (norepinephrine) causes blood vessels to constrict & is mainly used to increase blood pressure (pressor). Dobutamine helps the heart contract more forcefully & increase cardiac output (inotrope); it also can cause the blood vessels to dilate. Dobutamine is both a pressor & an inotrope--it makes blood vessels to constrict, & it increases cardiac output by causing the heart to beat faster & stronger.
Receptors. These three medications are used to support the heart and cardiovascular system ie. Blood pressure and heart rate. They are known as sympathomimetics and have a similar response to what you would think of as adrenaline. Each has variable effect on either heart rate, heart function (in terms of strength of 'squeeze') and on blood vessels which would translate to higher blood pressure.
I was wondering what are the differences of levophed, (norepinephrine) dopamine and dobutamine in terms of their action?
You Asked for It---- Dobutamine- direct b1 receptor stimulant or agonist in the sympathetic nervous system. Levophed- vasoconstrictor peripherally (alpha adrenergic effects) and beta adrenergic stimulant at the level of the heart and coronary vessels dopamine- dual b1 and Alpha adrenergic effects. Useful in hypovolemic shock because of conservancy of renal blood flow. Also, works centrally in other complex ways.