Phosphodiesterase type 5 inhibitors are a class of medications that includes prescription medications like Vidalista 10. Tadalafil is a PDE-5 inhibitor. It works by relaxing the blood vessels in your penis, which enhances blood flow to the region during erotic stimulation. This helps maintain and grow a firm, erect penis suitable for sexual activity. This pill should not be used by women. When taken alongside medications that contain nitrate, it could be harmful. Use of this prescription should be avoided if you have low blood pressure, severe heart or liver problems, or both. Tell your doctor about all current and past medical issues, including the following, before taking them. It's best not to drive if this makes you feel lightheaded.