Silditop 50 is a medication that contains the active ingredient sildenafil citrate. Silditop 50 should be taken orally 30 minutes to 1 hour before sexual activity, with a glass of water. The drug’s effectiveness is dependent on sexual stimulation. Silditop 50 does not cause an automatic or spontaneous erection; rather, it enhances the body’s natural response to sexual stimuli. Silditop 50 effects typically last 4-6 hours, during which time a sexually stimulated male may find it easier to acquire and sustain an erection.