Pentaerythritol tetranitrate is a pentaerythritol nitrate in which all four hydroxy groups of pentaerythritol have been converted to the corresponding nitrate ester. It is a vasodilator with properties similar to those of glyceryl trinitrate, but with a more prolonged duration of action, and is used for treatment of angina pectoris. It is also one of the most powerful high explosives known and is a component of the plastic explosive known as Semtex. It has a role as an explosive and a vasodilator agent.