Nitroglycerine has medical and non medical use. Medical use is in tiny quantities in a highly purified form. Non medical use is as an explosive (the original use). Nitroglycerine tablets, sublingual spray and injection are available. Both are used to treat angina pectoris, due to narrowing of coronary arteries supplying blood to the heart. Nitroglycerine dilates these vessels and relieves the pain due to angina pectoris. Intravenous nitroglycerine can also be used to bring down the blood pressure.