Nor./dop. Norepinephrine is the fight-flight neurotransmitter. Dopamine is for executive functions such as planning and alertness, etc.
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.