adrenergic agonist

reduced sympathetic outflow, peripheral vasodilation, decreased BP, and sedation

*decreased norepinephrine release

• mydriasis
• bronchoconstriction
• vasoconstriction (increased PVR, afterload, and ABP. Decreased renal and splanchnic blood flow)

bronchodilation, vasodilation, decreased serum potassium (activate sodium-potassium pump)

increased chronotropy, dromotropy, and inotropy 

found primarily in heart

adrenergic receptors activated by dopamine

D1 activation= vasodilation in kidney, intestine, and heart * increased renal blood flow promotes diuresis, does not impart any beneficial effects on renal function

D2 activation

• a1 0/+ 
• B1 +++
• B2 +
• inotropic support= increased CO
• increases myocardial oxygen consumption

infusion at a rate of 2-20mcg/kg/min

• a1 ++
• a2 ++ 
• B1 ++
• B2 +
• DA1 +++
• DA2 +++
• effects vary markedly with dose:

• 0.5- 3 mcg/kg/min - primarily activates dopaminergic receptors
• 3-10  mcg/kg/min - B1 stimulation increases contractility, HR, SBP, and CO
• 10-20 mcg/kg/min - a1 effects increase PVR and a fall in renal blood flow

proarrhythmic and chronotropic effect limit its usefulness in some patients

• noncatecholamine sympathomimetic
• similar to epinephrine, less potent
• longer duration of action
• tachyphylaxis
• IV bolus dose: 2.5mg-10mg

• a1 ++
• a2 ++
• B1++
• bolus 0.1mcg/kg
• Infusion rate:

• a1 +++
• dose IV bolus: 50-100 mcg 
• reflex bradycardia
• Infusion rate:

• a1++
• a2++
• B1+++
• B2+++
• dose dependent
• 0.01 - 0.05 mcg/kg/min chiefly B effects

• a1+
• a2+++
• sedative, analgesic, sympatholytic
• half life 2-3 hrs
• no ventilatory suppression
• SE: bradycardia, hypotension
• LD: 1mcg/kg
• infusion rate: 0.2-0.7 mcg/kg/hr

• a2 agonist
• antihypertensive
• negative chronotrope
• decreases anesthetic requirements, sedation, anxiolysis