Adrenergic Antagonists Flashcards
Non selective α1 & α2 blocker (2 drugs)
Phentolamine , phenoxybenzamine
Selective α1 antagonist ( 5 drugs)
(…Zosine)
1- Prazosin
2- doxazosine
3- terazosine
4- tamsulosine (very important)
5- alfuzosin
Selective α2 blocker
Yohimbine
DOC for pheochromocytoma
Phenoxybezamie ( α1&2 blocker)
Treating Raynaud’s disease by
Phenoxybenzamine
The Action of phentolamine& phenoxybezamine (3 points)
- Prevent V.C of peripheral BV
- Decreased peripheral resistance provokes tachycardia.
3.block α2 in the heart ❤️ increases cardiac output.
Indication of phentolamine (3 points)
1- diagnosis of pheochromocytoma
2- prevent dermal necrosis following extravasation of NE.
3- to treat hypertensive crisis.
Indication of phenoxybenzamine (2 points)
1- to treat hypertension with patient with pheochromocytoma.
2- Raynaud’s disease.
Adverse effects of phenoxybenzamine and phentolamine.(4 points)
1- Nasal congestion
2- inhibits ejaculation
3- miosis
4- reflex tachycardia.
The action of Selective α1 blockers
V.D
~ reducing BP with less reflex tachycardia .( because it is selective)
~ cause minimal changes in cardiac output , renal blood flow .
Therapeutic uses of selective α1 blockers ( zosin)
1- hypertension
2- hypertension with prostate enlargement
3- benign prostatic hyperplasia.(reduce urinary urgency.)
Adverse effect of (..zosin)
First dose syncope
Nasal congestion
Orthostatic hypotension
A selective α1A antagonist (2 drugs)
1- Tamsulosin ( very important)
2- alfuzosin
(α1A)receptor present in prostate and bladder neck.
A drug used in (BPH) benign prostate hypertrophy & kidney stones is ( 2 drugs)
Tamsulosin , alfuzosin
What is the therapeutic use of yohimbine
Used as aphrodisiac in the treatment of erectile dysfunction.
What is the action of yohimbine
Increase sympathetic out flow to the periphery. By blocking α2 receptor.
What is the adverse effects of α1 antagonists? ( 4 points)
1- orthostatic hypotension
2- Nasal congestion
3- inhibits ejaculation
4- reflex tachycardia.
