How Does Metoprolol Work? Metoprolol (Lopressor ® and Toprol-XL. Metoprolol controls high blood pressure and angina but does not cure them. Metoprolol extended-release tablets control heart failure but does not cure it. amlodipine, blood pressure, metoprolol succinate er. Metoprolol succinate n tartrate?. Metoprolol Succinate ER - does this work right away to lower blood. Metoprolol is used alone or together with other medicines to treat high blood pressure (hypertension). Mayo Clinic does not endorse companies or products. Lopressor (Metoprolol Tartrate). You have to take Metoprolol tartrate with food for it to work best. (On the other hand, you can take Toprol XL any time.) How does metoprolol work. Common Questions and Answers about How does metoprolol work. toprol. Toprol (metoprolol tartrate) and Toprol XL (metoprolol succinate). As this eMedTV page explains, metoprolol tartrate is approved for many uses, including the treatment of hypertension and angina. How Does the Drug Work? My blood pressure has been higher and my doctor raised the dosage of Metoprolol. Should it work immediately. Metoprolol tartrate. Metoprolol does not slow the. How to use metoprolol tartrate. See also Warning section. Drug interactions may change how your medications work or increase your risk for serious side effects.