Adrenergic Antagonist Flashcards
What is one of the most important effects alpha receptor antagonist have clinically?
Effects on the cardiovascular system. Baja la presión sanguínea.
Que ocurre si hay inhibición de alpha 1?
Ocurre vasodilatación bajando la presión por reflejos baroreceptor. Puede llevar a hipotension ortostatica. Si se bloquea también alpha 2 se libera mucha NE
Efecto del reflejo baroreceptor y la presión arterial.
-Reflejo baroreceptor activo, aumenta presión arterial por el simpatetico aumentando vasoconstricción
-Reflejo baroreceptor inactivo, disminuye presión arterial por el parasimpatetico disminuyendo vasoconstricción
Cuál es la distribución de receptores alpha 1 a y b?
70% de la prostata se componen de alpha 1 a.
Alpha 1 b se encuentra mayormente en la contraction del músculo liso vascular.
What is an alpha 1 antagonist drug that can help treat hypertension and BPH?
Prazosin non-selective between alpha 1 and and b that can also help reduce cholesterol
-However, Tamsulosin and silodosin are less likely to cause orthostatic hypotension.
What are two drug analogs of prazosin?
-Terazosin: less potent and induce apoptosis in prostate smooth muscle
-Doxazosin: bioavailability and metabolism like prazosin and induce apoptosis in prostate smooth muscle
What are three selective alpha 1 antagonist that only treats BPH?
-Alfuzosin: contraindicated in patients at risk of prolonged QT syndrome
-Tamsulosin: selective for Alpha 1 a
-Silodosin: selective for alpha 1 a
What drug is an alpha 2 selective antagonist that in the US is use as a supplement?
Yohimbine
What are two non selective alpha antagonist use to treat pheochromocytoma?
-Phenoxybenzamine: irreversible antagonist
-Phentolamine: competitive antagonist that is also used to treat hypertensive crisis from Clonidine or tyramine and prevent necrosis.
What is the difference between a first generation and a second generation beta blocker?
-First generation: Non-selective beta blocker
-Second generation: Selective beta 1 blocker
Why beta blockers like timolol are the standard of care for congestive heart failure?
The Donkey analogy. Pone un límite de velocidad sin disminuir la carga.
Beta blockers can also help treat glaucoma. Which two beta-blockers confer protection to retinal neurons?
Betaxolol and timolol