 <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]  a certain heart condition (coronary artery disease). 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.This medication will not relieve chest pain once it occurs. It is also not intended to be used just before physical activities (such as exercise, sexual activity) to prevent chest pain. Other medications may be needed in these situations. Consult your doctor for more details. How to use nitroglycerin transdermal Read the Patient Information Leaflet available from your pharmacist. Consult your doctor or pharmacist if you have any questions. Remove the patch from its pouch, and peel off the protective clear liner as directed. Usually, you will wear the patch on the upper arm or chest. However, you can wear it anywhere on the body below the neck and above the knees or elbows. Apply the patch to a clean, dry, and hairless area. Hair in the area may be clipped, but not shaved. Avoid areas with cuts or irritation. Do not apply the patch immediately after bathing or showering. Wait until your skin is completely dry. However, you may bathe, shower </s>