Metoprolol tartrate is a beta-blocker, specifically a selective beta1-adrenergic receptor antagonist. It works by blocking the effects of adrenaline (epinephrine) and noradrenaline (norepinephrine) on the heart and blood vessels.
This blockade reduces the heart rate and the force of heart contractions, leading to lower blood pressure. The reduced heart rate conserves energy, allowing the heart to work less hard. Simultaneously, the decreased contractile force diminishes the heart’s oxygen demand.
Importantly, metoprolol tartrate’s selectivity for beta1 receptors minimizes its effects on the lungs and bronchi, reducing the risk of bronchospasm compared to non-selective beta-blockers.
Lowering blood pressure and heart rate is achieved through multiple pathways influenced by beta-adrenergic receptor antagonism. It affects cardiac output, renin release, and peripheral vascular resistance, ultimately promoting cardiovascular stability.
Remember that metoprolol tartrate does not directly affect fluid balance; it does not act as a diuretic. Its effects on blood pressure are indirect, a consequence of its impact on the cardiovascular system.
