 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  as calcium channel blockers. 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. How to use verapamil oral Take this medication by mouth with or without food as directed by your doctor, usually 3 or 4 times daily. The dosage is based on your medical condition and response to treatment. Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day. For the treatment of high blood pressure, it may take a week before you get the full benefit of this drug. Keep taking this medication even if you feel well. Most people with high blood pressure do not feel sick. To prevent chest pain, it is very important to take this medication regularly as prescribed. This drug should not be used to treat chest pain when it occurs. Use other medications to relieve sudden attacks as </s>