What is the B2 effect of ephedrine?

What is the B2 effect of ephedrine?

• A. Increase Systemic Vascular Resistance
• B. No effect on SVR
• C. Increase heart rate via Beta-2 activation
• D. Decrease SVR

Answer: (D)

Beta-2 receptor activation causes relaxation of vascular smooth muscle, leading to vasodilation and a fall in systemic vascular resistance in the beds where this receptor effect predominates. Ephedrine is a mixed-acting sympathomimetic with direct beta-adrenergic activity, including beta-2, and indirect effects via norepinephrine release. The beta-2 component drives vasodilation, so the result is a decrease in SVR, even though alpha effects and increased cardiac output can influence overall blood pressure. The other options don’t reflect the vascular, beta-2–mediated decrease in SVR.

Beta-2 receptor activation causes relaxation of vascular smooth muscle, leading to vasodilation and a fall in systemic vascular resistance in the beds where this receptor effect predominates. Ephedrine is a mixed-acting sympathomimetic with direct beta-adrenergic activity, including beta-2, and indirect effects via norepinephrine release. The beta-2 component drives vasodilation, so the result is a decrease in SVR, even though alpha effects and increased cardiac output can influence overall blood pressure. The other options don’t reflect the vascular, beta-2–mediated decrease in SVR.