Carvan, as a selective β 1 receptor blocker, exerts a hypotensive effect by specifically blocking cardiac β 1 adrenergic receptors. Its mechanism involves multiple pathways such as reducing myocardial contractility, slowing sinoatrial node conduction, and inhibiting renin release.

The core mechanism of action of bevanolol

1. Selective receptor inhibition

Selective antagonism of β 1 adrenergic receptors (affinity 20-50 times higher than β 2 receptors) reduces the positive inotropic and chronotropic effects of catecholamine on the heart. This characteristic significantly reduces the bronchoconstriction side effects compared to non selective beta blockers.

2. Hemodynamic regulation

(1) Reduce cardiac output: achieved by reducing myocardial contractility and heart rate (usually by 10-20 beats per minute).

(2) Inhibition of renin release: Blocking the β 1 receptor in the glomerulus and reducing the activity of the renin-angiotensin system.

Pharmacodynamic characteristics

1. Effect and duration

The heart rate control effect appears 1-2 hours after oral administration, and the peak antihypertensive effect appears 3-6 hours. Half life of 10 hours supports 1-2 daily dosing regimen, with a trough to peak ratio>50% to ensure smooth blood pressure reduction.

2. Dose-dependent relationship

(1) Low dose (5-10mg) mainly slows down heart rate

(2) Medium to high doses (20-40mg) significantly reduce peripheral vascular resistance

Difference from other beta blockers

1. Compared to propranolol

It has almost no effect on β 2 receptors and reduces the risk of bronchoconstriction by 83% (clinical trial data), making it suitable for cautious use in patients with mild to moderate COPD.

2. Compared to metoprolol

The lipophilicity is lower, and the incidence of central nervous system side effects (such as abnormal dreams) is reduced by 40%, but the first pass effect is more pronounced (bioavailability is about 25%).

Special precautions

1. Prevention of withdrawal syndrome

Gradual reduction is required (halving the weekly dose), sudden discontinuation of medication may cause rebound hypertension and worsening angina, which is related to upregulation of beta receptors.

2. Drug interactions

(1) Enhance the hypoglycemic effect of insulin

(2) Non steroidal anti-inflammatory drugs may weaken their antihypertensive effect