Remove the cap by pushing it down and twisting it counter-clockwise. Recent heart or blood vessel problems. By controlling the enzyme, sildenafil helps to maintain an erection after the penis is stroked. If you are taking sildenafil to treat erectile dysfunction, you should know that it does not cure erectile dysfunction or increase sexual desire. If you are taking sildenafil to treat PAH, you will probably take sildenafil three times a day with or without food.The short answer is yes; you can take Viagra or its generic form, sildenafil, every r you need to or should, depends. Since each person is different, you should consult with a doctor.  · Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines called phosphodiesterase 5 (PDE5) inhibitors. These medicines prevent an enzyme called phosphodiesterase type-5 from working too quickly. The penis is one of the areas where . Viagra Increases Your Sex Drive. Another common myth about Viagra is that it can increase your sex drive and cause you to feel more motivated to have sex. Viagra is designed to improve your physical performance during sex — that is, your ability to get and maintain an erection.