It is possible to say that men who struggle to keep their penis firm during sexual activity and keep it that way for an extended period of time are suffering from erectile dysfunction. All of these men take vidalista 10, a medication prescribed by their doctor, as a remedy. This medication, which contains the active chemical tadalafil, belongs to the class of PDE-5 inhibitors since it helps men with weak erections stay solid during sexual activity. Vidalista is essentially a weekend drug because its effects take 36 to 48 hours to manifest in the body.