Alpha antagonists/blockers

Question 0

PHENoXyBenzAmine

Answer 0

A1 and A2 Tx: Pheochromacytoma

Block of A1: incr B1 receptors -> incr HR, etc

Question 1

PHENtolAmine

Answer 1

block A1 and A2
Block of A1: dilate vessels -> decr PBR periph vascular resistance - > decr BP ——> BARORECEPTORS –> incr NE (?) -> incr HR!

Block of A2 (on presynaptic terminals): Incr NE (incr HR) and Incr Insulin

Question 2

PrAzozin

Answer 2

A1 blocker: Vasodilate -> decr PVR -> decr BP
2) decr CO
3) dilate bladder phincter
!!! Since A2 is not blocked: A2 -> decr NE (also Decr insulin) —–> no reflex tachy when decr BP as above