Sildenafil Teva belongs to a group of medicines called phosphodiesterase type 5 inhibitors. It works by helping to relax the blood vessels in your penis, allowing blood to flow into your penis when you get sexually excited. Sildenafil Teva will only help you to get an erection if you are sexually stimulated. You should not take Sildenafil Teva if you do not have erectile dysfunction. You should not take Sildenafil Teva if you are a woman.