metoprololi

Metoprolol, sometimes written metoprololi, is a prescription beta-blocker used to treat cardiovascular conditions. It is available in two main forms: metoprolol tartrate, a short-acting preparation that can be given orally or intravenously, and metoprolol succinate, an extended-release form used mainly for chronic conditions and taken orally.

Mechanism of action and effects: Metoprolol is a selective antagonist of beta-1 adrenergic receptors in the heart. By blocking these receptors, it reduces heart rate, lowers myocardial contractility and conduction through the atrioventricular node, and decreases blood pressure. The resulting reduction in myocardial oxygen demand helps relieve angina and stabilize certain rhythm disorders. At usual doses, the cardioselectivity minimizes impact on beta-2 receptors in the lungs, but higher doses can still cause bronchospasm in susceptible individuals.

Indications and uses: Metoprolol is commonly prescribed for hypertension, stable angina, and certain arrhythmias. It is also used in the management of myocardial infarction and, in its extended-release form, for heart failure with reduced ejection fraction under specific regimens. Off-label, it may be employed for migraine prophylaxis and certain anxiety-related symptoms in some patients.

Contraindications and cautions: It should not be used in significant bradycardia, high-grade AV block, uncompensated heart failure, or cardiogenic shock. Caution is advised in patients with asthma or chronic obstructive pulmonary disease, diabetes, or severe hypotension. Abrupt withdrawal after long-term use can worsen cardiac symptoms. Interactions with other heart-suppressing medications and certain antidiabetic drugs can occur.

Pharmacokinetics: Metoprolol has variable oral bioavailability due to first-pass metabolism, is primarily processed by the liver via CYP2D6, and is excreted in the urine. Tartrate has a shorter half-life, while succinate provides once-daily dosing.