What should I discuss with my healthcare provider before taking metoprolol? You should not use this medicine if you are allergic to metoprolol, or other beta-blockers (atenolol, carvedilol, labetalol, nadolol, nebivolol, propranolol, sotalol, and others), or if you have: Metoprolol, marketed under the tradename Lopressor among others, is a medication of the selective β 1 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. Actifed Cold and Allergy contains a combination of chlorpheniramine and phenylephrine. Chlorpheniramine is an antihistamine that reduces the natural chemical histamine in the body. Find patient medical information for Lopressor Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Consumer information about the medication METOPROLOL - ORAL (Lopressor), includes side effects, drug interactions, recommended dosages, and storage information. Read more about the prescription drug METOPROLOL - ORAL. Jay W. Marks, MD. Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles. Cozaar (Losartan) is a good blood pressure-lowering medicine that protects kidney function like an ACE inhibitor, but with fewer side effects. Lopressor (metoprolol tartrate) lowers high blood pressure, controls chest pain, and helps treat heart failure and heart attack. You need to take it with food and can't miss a dose. Most people get heartburn once in a while—that achy, fiery feeling in your chest after polishing off a big, fatty meal, also known as acid reflux. Before taking this medicine. You should not use this medicine if you are allergic to Lopressor, or other beta-blockers (atenolol, carvedilol, labetalol, nadolol, nebivolol, propranolol, sotalol, and others), or if you have: Metoprolol is used alone or in combination with other medications to treat high blood pressure. It also is used to prevent angina (chest pain) and to improve survival after a heart attack.