Nitro-G 6.4 Tablet is a medication used to treat and prevent heart-related chest pain (angina) by relaxing and widening blood vessels. It should be taken as directed by a doctor, with or without food, and at a fixed time each day. Over time, tolerance can develop, so a specific dosing schedule is essential. Common side effects include severe headaches, lightheadedness, and serious side effects. It should not be used if you are taking other medications, have other health conditions, or are pregnant or breastfeeding. Consult your doctor before taking this medication.