The uses of Isoptin SR include: Verapamil is used with or without other medications to treat high blood pressure (hypertension). Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Verapamil is called a calcium channel blocker. It works by relaxing blood vessels so blood can flow more easily.
Verapamil is also used to prevent chest pain (angina). It may help to increase your ability to exercise and decrease how often you may get angina attacks. Verapamil is also used to control your heart rate if you have a fast/irregular heartbeat (such as atrial fibrillation). It helps to lower the heart rate, helping you to feel more comfortable and increase your ability to exercise.