Vilitra, which contains the active ingredient vardenafil, is used to treat erectile dysfunction by increasing blood flow to the penis. It belongs to a class of drugs called PDE5 inhibitors. Combining Vilitra with nitrates—commonly prescribed for chest pain (angina)—can cause a dangerous and potentially life-threatening drop in blood pressure. Both drugs relax blood vessels, and when taken together, this effect is significantly amplified, leading to severe hypotension, dizziness, fainting, heart attack, or stroke. Due to this serious interaction, the combination is strictly contraindicated. Patients must inform their doctor of all medications they take to avoid such hazardous drug interactions.