Erectile dysfunction or impotence occurs when you cannot get an erection or hold an erection strong enough to perform sensory interactions. The main reason for this is the insufficient blood flow in the penis of men during sexual activity. Unable to maintain an erection can cause problems in your relationship or your self-confidence, but there are ways to treat or even treat the condition. Buy tadalista 20 Mg online which is a drug used to treat erectile dysfunction in men over 18 years of age. The active ingredient of the drug is tadalafil which is a PDE5 inhibitor. Its therapeutic effect is achieved by inhibiting the activity of an enzyme called PDE5 or phosphodiesterase type 5 inhibitor.