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Evidence-based medicine, rational drug use
Beta-blockers are commonly used drugs in cardiology, and are widely used in coronary heart disease, arrhythmia, hypertension, chronic heart failure, etc.
Metoprolol and Bisoprolol are both highly selective beta1 blockers. What are the differences between them? Follow Jie Xiaoyao, let’s take a look together!
Different pharmacological mechanisms
Metoprolol is a cardioselective beta1-adrenoceptor blocker, but at higher plasma concentrations also inhibits beta2, which is primarily present on bronchial and vascular smooth muscle Adrenergic receptors.
Clinical pharmacology studies have shown that metoprolol has the following beta-blocking activities: reducing heart rate and cardiac output at rest and during exercise, reducing systolic blood pressure during exercise, inhibiting Isoproterenol-induced tachycardia, slow reflex orthostatic tachycardia.
Bisoprolol is a highly selective beta1-adrenoceptor blocker (cardioselective) with no intrinsic sympathomimetic and membrane stabilizing activity in the therapeutic dose range. Bisoprolol fumarate also inhibits β2-adrenoceptors on bronchial and vascular smooth muscle at over-therapeutic doses (≥20 mg). Therefore, it is important to use the lowest effective dose to maintain high selectivity to the heart [1-3].
Indications and dosages vary
Metoprolol can be used clinically for angina pectoris, heart failure, hypertension, early treatment of myocardial infarction, hyperthyroidism, hypertrophic cardiomyopathy, and arrhythmia. Bisoprolol can be used clinically for hypertension, angina pectoris, and heart failure. What is the difference between the two in indications and dosage?
Table 1 Differences between metoprolol and bisoprolol
Note: This form is compiled from various drug inserts. There may be inconsistencies in the usage and dosage of the drug inserts of different manufacturers. It is only used as a reference for clinical medication.
Contraindications vary
When is metoprolol contraindicated? In what situations is bisoprolol banned?
▍Metoprolol
Allergy to metoprolol and related derivatives or any excipients, allergy to other beta-blockers (cross-sensitivity between beta-blockers may occur ).
Metoprolol is contraindicated in patients with myocardial infarction with heart rate <45 beats/min; second- and third-degree heart block; significant first-degree heart block (P-R interval ≥ 0.24 seconds); systolic blood pressure <100 mmHg; or patients with moderate to severe heart failure [4-5].
Metoprolol tartrate tablets are contraindicated in the presence of sinus bradycardia, first-degree or higher heart block, cardiogenic shock and significant cardiac failure when using metoprolol tartrate tablets for the treatment of hypertension and angina pectoris exhausted patients.
Allergy to metoprolol and related derivatives or any excipients; allergy to other beta-blockers (crossover between beta-blockers may occur sensitivity).
Sick sinus syndrome; severe peripheral arterial circulation disorder [5].
Metoprolol succinate extended-release tablets are contraindicated in severe bradycardia, second or third degree heart block, cardiogenic shock, decompensated heart failure, sick sinus Atrial nodal syndrome (unless a permanent pacemaker is installed), and patients with hypersensitivity to any of its components [6].
▍bisoprolol
Contraindicated in the following patients:
Patients with acute heart failure or decompensated heart failure requiring intravenous inotropes;
Cardiogenic shock;
Second or third degree AV block (without a pacemaker);
patients with sick sinus syndrome;
Sinus block;
Patients with symptomatic bradycardia (symptomatic bradycardia);
Symptomatic hypotension;
Severe bronchial asthma;
patients with severe peripheral arterial occlusive disease and Raynaud’s syndrome;
Patients with untreated pheochromocytoma;
patients with metabolic acidosis;
Patients with known hypersensitivity to bisoprolol, its derivatives, or any component of this product [1-3].