The specific agent in on-market formulations of metoprolol is either metoprolol tartrate or metoprolol succinate, where tartrate is an immediate-release formulation and the succinate is an extended-release formulation (with 100 mg metoprolol tartrate corresponding to 95 mg metoprolol succinate). Metoprolol is used alone or together with other medicines to treat high blood pressure (hypertension). High blood pressure adds to the workload of the heart and arteries. If it continues for a long time, the heart and arteries may not function properly. Read on to learn about the side effects of metoprolol, including common, severe, and long-term side effects, and how to manage them. Metoprolol is a beta-blocker that affects the heart and circulation (blood flow through arteries and veins). Metoprolol is used to treat angina (chest pain) and hypertension (high blood pressure). Metoprolol is also used to lower your risk of death or needing to be hospitalized for heart failure. DESCRIPTION oceptor blocking agent, for oral administration, available as extended-release tablets. Metoprolol succinate extended-release tablet has been formulated to p ovide a controlled and. Metoprolol (Lopressor®) is a medication that lowers your blood pressure and heart rate, making it easier for your heart to pump blood to the rest of your body. Metoprolol succinate is a once-daily, extended-release beta-blocker used to treat high blood pressure, angina, and heart failure. It lowers cardiovascular risk, improves exercise tolerance, and reduces hospitalizations. Metoprolol is a prescription medication used to treat the symptoms of Hypertension, Acute Myocardial Infarction, Congestive Heart Failure, Angina. Learn about side effects, dosages, drug interactions, and more. Toprol XL (Metoprolol Succinate) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. Find patient medical information for Metoprolol (Lopressor, Toprol XL, others) on WebMD including its uses, side effects and safety, interactions, pictures, warnings, and user ratings.