 <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]  that have a certain heart condition (coronary artery disease). It may also be used before physical activities (such as exercise, sexual activity) to help prevent chest pain.Nitroglycerin belongs to a class of drugs known as nitrates. Angina occurs when the heart muscle is not getting enough blood. This drug works by relaxing and widening blood vessels so blood can flow more easily to the heart. How to use Nitrostat Tablet, Sublingual Ask your doctor now for exact instructions on how to use your nitroglycerin and when to call for emergency medical help (911). Read the Patient Information Leaflet if available from your pharmacist before you start using nitroglycerin and each time you get a refill. If you have any questions, ask your doctor or pharmacist. Sit down before using this medication. Place 1 tablet under the tongue and allow it to dissolve as directed by your doctor. Do not chew or swallow the tablet. The dosage is based on your medical condition and response to treatment. If you are using this medication to prevent chest pain before physical activities, use it 5 to 10 minutes before the activity. If you are using this medication to relieve chest pain once it occurs, use it as soon as possible. If your chest pain has </s>