Metoprolol

Metoprolol is a selective β1-receptor blocker. It is used to treat high blood pressure, chest pain due to poor blood flow to the heart, and a number of conditions involving an abnormally fast heart rate. It is also used to prevent further heart problems after a myocardial infarction and to prevent migraine headaches.

Metoprolol wird gewöhnlich durch den Mund genommen oder intravenös verabreicht und ist rezeptpflichtig.

Pharmacodynamics

Metoprolol is a beta-1-adrenergic receptor blocker that acts specifically on cells in the heart. The effect on beta-2 receptors is negligible. This inhibition decreases cardiac output through negative chronotropic and inotropic effects (heart rate and beating force are decreased).

Pharmacokinetics

When administered orally, metoprolol is almost completely absorbed in the gastrointestinal tract. Maximum serum concentration is reached 20 min after intravenous administration and 1-2 hours after oral administration. The bioavailability of metoprolol is 100% with intravenous administration and approximately 50% with oral administration. Plasma protein binding is approximately 11%. Metoprolol undergoes significant hepatic first-pass metabolism, accounting for approximately 50% of the administered dose. Metoprolol metabolism is mainly determined by the activity of CYP2D63 and to a lesser extent by the activity of CYP3A4. Metoprolol is excreted primarily through the kidneys. The immediate-release formulations of metoprolol have a half-life of approximately 3-7 hours

InteractionsWhen

Side effects

Common side effects include sleep disturbances, fatigue, feeling weak, and abdominal discomfort. Severe side effects may occur in larger doses. Greater caution is needed with use in those with liver problems or asthma. Discontinuation of the drug should be gradual to reduce the risk of further health problems.

Toxicological Data

LD50 (rat, oral): 3470 mg-kg-1