PDA Block 1 Adrenergic Agonist (Sympathomimetics)

Question 1

Epinephrine (Sym in adrenal Medulla)

Answer 1

Receptor: a1, a2, B1, & B2.
Target Organ: CV, Respiratory, Metabolic
Effect- CV: Increase BP and contractile force (B1)
Increase CO (B1), Systo BP, decrease diastolic BP,
Dilation of Sk.(B2).
Net effect: decrease peripheral vascular resistance.
Resp: bronchodilator
Metabolic: induce Hyperglycemia(increase gluconeogenesis, glycogenolysis, inhibit insulin
Induce Lipolysis (increase FFA)

Use: Anaphylactic Shock
Bradyarrythmias- restore rhythm in cardiac arrest.

Question 2

Isoproterenol (IV only)

Answer 2

Receptor: B1, B2
Target Organ: CV, Respiratory
Effect - CV: Increase HR and Contractile force (B1)
Increase CO(B1), Decrease MAP. Decrease Periph Resist.

Use: Emergency: Stimulates HR during bradycardia or Heart Block

Question 3

Dopamine (IV)

Answer 3

Receptor: DA1, B1, a1
Target Organ: CV
Effect: Low dose: Vasodilation of renal/ mensenteric artery
Peripheral resistance (DA1)
Med dose: Increase HR, contractile F. CO(B1)
High dose: Vaconstrict - Increase Peripheral Resistance (a1)

Use: Decompensated Heart Failure, shock (cardio genie, septic)

Question 4

Dobutamine (IV)

Short acting

Answer 4

Receptor: B1
Target Organ: CV
Effects: Increase CO, Contractility and Output
Min. Change in Peripheral Resistance and BP.

Use: Short term tx. Cardiac decompensation after surgery or CHF, MI

Question 5

Methyl dopa (Oral)
Converted to a-methlynoepinephrine in adrenegic

Answer 5

Receptor: a2
Target: CNS
Effect: Decrease SNS flow by activating a2 in CV control in CNS
= decrease BP

Use: Anti-Hypertensive

Question 6

Norepinephrine (sympathetic so NT)

Answer 6

Receptor: a1, a2, B1
Organ/ Target: CV a1 mainly
Effect: Peripheral Vasoconstriction (a- mediated)
Increase BP, Reflex Bradycardia (Vagally mediated)

Use: Vasoconstrict in Intensive care (eg. Shock)
Increase BP during decrease SNS tone (eg.Neuro Injury or Spinal Anesthesia)