Selective α AR Sympatholytics Flashcards
What type of antagonist is Phentolamine?
Non-selective α antagonist
Blocks both α1 and α2 receptors, inhibiting catecholamine-induced vasoconstriction, leading to vasodilation.
What conditions is Phentolamine used for?
- Pheochromocytoma crisis
- Hypertensive emergencies
- Frostbite
- Raynaud’s phenomenon
- Local infiltration/extravasation of catecholamines/vasoconstrictors
These conditions involve severe hypertension or vascular complications.
What is the MoA of phentolamine?
“Blocks both α1 and α2 receptors, inhibiting catecholamine-induced vasoconstriction
=vasodilation”
What are the side effects of Phentolamine?
- Hypotension
- Reflex tachycardia
Blood pressure should be monitored closely due to risk of significant drops.
What type of antagonist is Prazosin?
α1 antagonist
Blocks α1 receptors to reduce vasoconstriction.
What are the uses of Prazosin?
- Hypertension
- PTSD-related nightmares
- Benign prostatic hyperplasia (BPH)
Effective in managing both blood pressure and urinary symptoms related to BPH.
What are the side effects of Prazosin?
- Orthostatic hypotension
- Dizziness
Caution is advised during initiation and dose adjustments due to potential for significant drops in blood pressure.
What type of antagonist is Tamsulosin?
α1A antagonist
Selectively blocks α1A receptors in the prostate and bladder neck.
What condition is Tamsulosin primarily used to treat?
Benign prostatic hyperplasia (BPH)
Specifically targets urinary symptoms associated with BPH.
What are the side effects of Tamsulosin?
- Dizziness
- Orthostatic hypotension
- Ejaculatory dysfunction
Patients should be monitored for hypotensive episodes during treatment.
What is the MoA of prazosin?
Blocks α1 receptors to reduce vasoconstriction
What is the MoA of tamsulosin?
Selectively blocks α1A receptors in the prostate and bladder neck
