Vilitra 20 (vardenafil) with nitrates (such as nitroglycerin or isosorbide medicines used for chest pain/angina) can cause a dangerous, potentially life-threatening drop in blood pressure. Here’s what happens in the body: Both vardenafil (Vilitra) and nitrates widen blood vessels (vasodilation). When taken together, this effect can become strongly additive and uncontrolled. Blood pressure can fall suddenly to very low levels. Possible consequences Severe dizziness or fainting Blurred vision or confusion Chest pain due to reduced blood flow to the heart Heart attack or stroke in extreme cases Shock (very low blood pressure requiring emergency treatment) Why this interaction is serious Doctors consider PDE5 inhibitors like Vilitra and nitrates to be an absolute contraindication—meaning they should never be used together under any circumstances. Even if nitrates are taken hours after Vilitra (or vice versa), the risk can still persist because the drug effect can last in the body. Important note If someone has taken Vilitra and then develops chest pain, they should not self-take nitrates and must seek emergency medical help immediately. If you want, I can also explain how long you should wait after Vilitra before nitrates become safe, or what alternatives are used for chest pain in people who take ED medications.