The active component of Vidalista 80, a drug prescribed to treat erectile dysfunction or impotence in men, is tadalafil. It belongs to a class of drugs called phosphodiesterase type 5 (PDE5) inhibitors, which work by increasing blood flow to the penis during erotic stimulation. Should you decide to take the 80mg Tadalafil tablets by mouth, make sure you drink a glass of water first. It is recommended that you take 80 mg tablets of Vidalista at least 30 to 60 minutes before engaging in sexual activity. You have to follow the dosage instructions provided by your doctor.