Drugs

Question 1

Biosynthetic Pathway of Endogenous Catecholamines.

Answer 1

Tyrosine -> Dopa -> NEpi -> Epi

Question 2

Alpha 1 Adrenergic Receptor

Answer 2

• G Protein -> dissociation of alpha and beta gamma subunit
• Activation of phospholipase C
• Cleaves PIP2 (Phosphatidylinositol 4,5-bisphosphate) to IP3 and DAG
• IP3 increase intracellular Ca
• Ca activates protein kinase C

Vasoconstriction

Increased SVR and PVR

Question 3

Beta Adrenergic Receptor

Answer 3

• alpha subunit binds to GTP
• Activates adenylate cyclase
• Converts ATP to cAMP
• Binds to regulatory protein on protein kinase A
• Increases intracellular calcium

Beta 1 = inotropy and chronotropy

Beta 2 = vasodilation, bronchodilation

Question 4

Milrinone

Answer 4

• Bipyridines
• Phosphodiesterase III inhibitor
• Increase cAMP
• +inotropy, lusitropy
• Vasodilation (both systemic and pulm), decrease SVR
• No HR effects
• Bound 70% to plasma proteins
• Renal excretion
• Amrinone (caused cytopenia)

50-75 mcg/kg load

0.25-1 mcg/kg/min