 <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]  may help to increase your ability to exercise.Ranolazine works differently than other drugs for angina, so it can be used with your other angina medications (including nitrates, calcium channel blockers such as amlodipine, beta blockers such as metoprolol). It is thought to work by improving how well the heart uses oxygen so that it can do more work with less oxygen. How to use Ranexa Read the Patient Information Leaflet if available from your pharmacist before you start taking ranolazine and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Take this medication by mouth with or without food as directed by your doctor, usually twice daily. Swallow this medication whole. Do not crush, chew, or split tablets. Doing so can release all of the drug at once, increasing the risk of side effects. 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. The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor </s>