Alpha Blockers (Alpha Adrenergic Antagonist & Alpha II Agonists)

Question 1

Indications of Alpha I Antagonists (blockers)

Answer 1

Hypertension (usually for resistance)
BPH
Pheochromocytoma

Question 2

MOA of Alpha I Antagonists

Answer 2

• Found in smooth muscle
  »> blood vessels & urinary tract
• Causes vasodilation and reduction in BP

Question 3

Alpha I Antagonist Examples

Answer 3

Non Selective

• prazosin
• terazosin
• doxazosin

Used in BPH

• Alfuzosin
• doxazosin
• sildosin
• tamsulosin

Question 4

Adverse Effects of Alpha I Antagonists

Answer 4

• ORTHOSTATIC HYPOTENSION
• dizziness, faint
• ^^ all more pronounced after first dose
• Reflex Tachycardia
• Nasal congestion
• inhibition of ejaculation

increased of falls (also linked to medicated BPH pts)

• advise to rise slowly esp when first starting therapy
• also be careful with sleep meds, PDE5 inhibitors (seldinifil)

Question 5

Alpha 2 Agonists Examples

Answer 5

Clonidine
Guanficine
Methyldopa (PREFERRED IN PREGNANCY)

Question 6

Alpha 2 Agonists Adverse Effects

Answer 6

Clonidine: Sudden discontinuation of clonidine can lead to rebound hypertension (excessive sympathetic activity)
AE: drug potential bc of high symptoms
orthostatic hypotension is minimal

Methyldopa: hemolytic anemia and hepatic necrosis

Other notable ones: dry mouth (chew sugarless gum, sugarless candy)