Nitrox XL 2.6mg Tablet is used to treat and prevent heart-related chest pain (angina). Angina occurs when the heart muscle is not getting enough blood. This medicine works by relaxing and widening blood vessels so blood can flow more easily to the heart. Nitrox XL 2.6mg Tablet should be taken in the dose and duration as advised by your doctor. It may be taken with or without food, preferably at a fixed time each day. Do not consume more than the recommended dose, as this may have harmful effects on your body. You can develop tolerance to this medicine over time, which means that the same dose becomes less effective. You have to stick to a really specific dosing schedule to prevent this from happening. The most common side effect of this medicine is a headache which may be severe. This can sometimes be helped by drinking plenty of fluids and avoiding alcohol. You may also experience lightheadedness, which could increase your risk of having a fall. There are other, rarer side effects, some of them serious. Ask your doctor and read the leaflet which comes with the medicine to make sure you are keeping safe. Do not use this medicine if you are taking medicines to treat high blood pressure in your lungs (pulmonary hypertension), erectile dysfunction or if you have anemia or glaucoma (increased pressure inside the eye). Always tell your doctor what other health conditions you have and what other medicines you are taking. It is best not to drink alcohol with this medicine as it increases some of the side effects. If you are affected by dizziness, avoid driving. If you are pregnant, planning to become pregnant, or breastfeeding, ask your doctor before taking this medicine.