Passage: Metoprolol, marketed under the tradename Lopressor among others, is a medication of the selective β1 receptor blocker type. 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 myocardial infarction and to prevent headaches in those with migraines.Metoprolol is sold in formulations that can be taken by mouth or given intravenously. The medication is often taken twice a day. The extended-release formulation is taken once per day. Metoprolol may be combined with hydrochlorothiazide (a diuretic) in a single tablet.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. Greater care is required with use in those with liver problems or asthma. Stopping this drug should be done slowly to decrease the risk of further health problems.Metoprolol was first made in 1969, patented in 1970, and approved for medical use in 1982. It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system. It is available as a generic drug. In 2016, it was the 6th most prescribed medication in the United States, with more than 74 million prescriptions.

Question: Is Metoprolol guaranteed not to cause side effects in pregnancy?
not