Labetalol is a nonselective alpha-1 and Beta adrenergic antagonist. In the vasculature, alpha-1 receptors are responsible for vascular constriction which increases blood pressure/systemic vascular resistance. Antagonism would decrease the BP. At the same time, Beta-1 receptors in the heart are responsible for a positive inotropic and chronotropic effects, increasing both heart rate and contractility. Antagonism at the Beta-1 receptors in the heart would decrease heart rate.
A) Albuterol- short acting Beta-2 agonist, used for bronchodilation in the lungs. There is typically no large systemic absorption. C) Phentolamine- a non-selective alpha-1 and alpha-2 reversible competitive antagonist, it can be used in hypertensive emergencies or in Raynaud phenomenon. It would not effect heart rate. D) Prazosin- an alpha-1 antagonist, it can be used to treat hypertension or to treat nightmares associated with PTSD. It would not effect heart rate E) Propanolol- a non-cardio-selective Beta antagonist, used for many cardiac issues, for anxiety, and in pheochromocytomes. This would not affect systemic vascular resistance.
submitted by sajaqua1(228), 2019-06-05T01:54:50Z
Labetalol is a nonselective alpha-1 and Beta adrenergic antagonist. In the vasculature, alpha-1 receptors are responsible for vascular constriction which increases blood pressure/systemic vascular resistance. Antagonism would decrease the BP. At the same time, Beta-1 receptors in the heart are responsible for a positive inotropic and chronotropic effects, increasing both heart rate and contractility. Antagonism at the Beta-1 receptors in the heart would decrease heart rate.
A) Albuterol- short acting Beta-2 agonist, used for bronchodilation in the lungs. There is typically no large systemic absorption. C) Phentolamine- a non-selective alpha-1 and alpha-2 reversible competitive antagonist, it can be used in hypertensive emergencies or in Raynaud phenomenon. It would not effect heart rate. D) Prazosin- an alpha-1 antagonist, it can be used to treat hypertension or to treat nightmares associated with PTSD. It would not effect heart rate E) Propanolol- a non-cardio-selective Beta antagonist, used for many cardiac issues, for anxiety, and in pheochromocytomes. This would not affect systemic vascular resistance.