Beta-Blocker | The University Of Western Ontario

University:
The University Of Western Ontario
Course:
MED 5161 | Principle of Medicine
Academic year:

2025
Views:

107

Pages:

3
Author:

Kyuwon J.

Beta-Blocker ● Beta-blockers block β-adrenergic receptors ○ Sympathetic nervous system ● Reduction of various types of adrenaline ○ Epinephrine ○ Noradrenaline ■ Norepinephrine ● Slower heart rate ● Reduction of blood pressure ● Decreased cardiac load B-Receptor ● β1 receptor ○ Mainly in heart ○ Increase of heart rate ○ Increases contractability ● β2 receptor ○ Mainly on lungs ○ Vascular smooth muscle ○ Skeletal muscle ○ Bronchodilation ○ Vasodilation Mechanisms ● blocker = antagonizing B-adrenergic receptor ○ Decrease in heart rate ■ Negative chronotropic effect ○ Decrease in Myocardial contractility ■ Negative intropic effect ○ Decrease in cardiac output ○ Decreased blood pressure ○ Decreased Renin release level ■ In kidney = Reduced myocardial O2 demand Classification ● Non-selective β-blocker ○ Blockage of β1 and β2 receptors ■ ex) ● Propranolol ● Nadolol ● Timolol ○ Significance: ■ Causation of bronchoconstriction ● Cardio selective β-blockers ○ Blocks β1 receptors (preferably) ■ ex) ● Metoprolol ● Atenolol ● Bisoprolol ● Esmolol ○ ADV ■ Less risk on bronchospasm ● Β-blocker + vasodilatory effect ■ ex) ● Carvediol → β + α1 blockade ● Labetalol → β + α blockade ● Nebivolol → nitric oxide mediated vasodilation