Metoprolol
medication of the selective β1 receptor blocker type

Metoprolol, sold under the brand names Lopressor and Toprol-XL among others, is a medication used to treat angina, high blood pressure and a number of conditions involving an abnormally fast heart rate. It is also used to prevent further heart problems after myocardial infarction and to prevent headaches in those with migraines. It is a beta blocker, specifically a selective competitive β1 receptor blocker, and is taken by mouth or is given intravenously.
Common side effects include trouble sleeping, feeling tired, feeling faint, and abdominal discomfort. Large doses may cause serious toxicity. Risk in pregnancy has not been ruled out. It appears to be safe in breastfeeding. The metabolism of metoprolol can vary widely among patients, often as a result of hepatic impairment or CYP2D6 polymorphism.
Metoprolol was first made in 1969, patented in 1970, and approved for medical use in 1978. It is on the World Health Organization's List of Essential Medicines.
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This entry incorporates text from “Metoprolol” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.