drug main uses (Alpha Blockers)

Question 1

Phenoxybenzamine (Dibenzyline)

Answer 1

a1 & a2

• Decrease BP by decrease in peripheral arterial resistance
• Irreversible Non-competitive inhibition

Prevent severe catecholamine-induced hypertensive episodes from PRE-OP pheochromocytoma pts

Question 2

Phentolamine (OraVerse)

Answer 2

a1 & a2

• Decrease BP by decrease in peripheral arterial resistance
• Irreversible Non-competitive inhibition

Short-acting drug used DURING Pheo surgery and in Dx of Pheo; reverse acute systemic vasoconstriction; prevent local dermal tissue necrosis from a-agonist injection; dental anesthetic reversal

Question 3

Prazosin (Minipress)
Terazosin (Hytrin)
Doxazosin (Cardura)

Answer 3

a1

• Decreased peripheral arterial resistance
• Reversible Competitive inhibition

Decrease mild to moderate HTN when given with diuretic; relax smooth muscle of bladder neck and prostatic urethra in BPH; Tx of Reynaud’s; PTSD nightmares

Question 4

Tamsulosin (Flomax)

Silodosin (Rapaflo)

Answer 4

a1

• Decreased peripheral arterial resistance
• Reversible Competitive inhibition

Block a1A receptor found in bladder neck and prostate to treat BPH with less systemic effect

Question 5

Alfuzosin (Uroxatral)

Answer 5

a1

• Decreased peripheral arterial resistance
• Reversible Competitive inhibition

Treats BPH but not specific for a1A like above; still “uroselective” because of accumulation in prostatic tissue