XELOL 50 ER is Metoprolol 50mg Extended Release Tablets – a beta-blocker used to treat?chest pain?(angina),?heart failure, and?high blood pressure. Lowering?high blood pressure?helps prevent strokes,?heart attacks, and?kidney?problems.XELOL 50 ER works by blocking the action of certain natural chemicals in the body (such as?epinephrine) that affect the?heart?and?blood?vessels. This lowers?heart rate,?blood pressure, and strain on the?heart.