What alternatives can I use for erectile dysfunction? Do not take more or less of it or take it more often than prescribed by your doctor. What special dietary instructions should I follow? If you have certain health conditions or are taking certain medications, your doctor may tell you to take sildenafil less often. It is typical for students to contact several labs at a time and you may not hear back from each one. Before starting, stopping, or changing any medications while taking sildenafil, please get the advice of your doctor or pharmacist. · a light-headed feeling, like you might pass out. Common sildenafil side effects may include: flushing (warmth, redness, or tingly feeling); headache, dizziness; heartburn, nausea, or upset stomach. abnormal vision (blurred vision, changes in color vision) runny or stuffy nose, nosebleeds; sleep problems (insomnia); or. Yes, sildenafil (the active ingredient in Viagra), manufactured by Teva, is the FDA approved generic for brand Viagra. It launched on December 11, The announcement from Teva can be seen here. It is available in each strength that the brand is available in: Being an FDA approved generic indicates that the generic is considered to . Si tomas Viagra para mantener una erección, no debes hacerlo más de una vez al día. La dosis habitualmente indicada es de 50 mg, pero puede variar entre 10 y mg, dependiendo del efecto sobre cada persona y de si se padece alguna enfermedad, como insuficiencia hepática, renal o si se toma algún otro fármaco.