 <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]  and decrease the frequency of chest pain attacks. It should not be used to treat chest pain when it occurs. Use other medications (such as sublingual nitroglycerin) to relieve attacks of chest pain as directed by your doctor. Consult your doctor or pharmacist for more details.This medication is known as a calcium channel blocker. It works by relaxing and widening blood vessels so blood can flow more easily. How to use Procardia XL Take this medication by mouth with or without food as directed by your doctor, usually once daily. Swallow the tablets whole. Do not crush or chew the tablets. Doing so can release all of the drug at once, increasing the risk of side effects. Your doctor may gradually increase your dose. Follow your doctor's instructions carefully. Dosage is based on your medical condition and response to treatment. Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details. Use this medication regularly in order to get the most benefit from it. Remember to take it at the same time each day. Keep taking this medication even if you feel well. Most people with </s>