You can find Katelyn on Doximity for more information. Click here for an email preview. Four-year review of sildenafil citrate. Keep out of the reach of children. Push the plunger of the syringe, then insert the tip into the bottle while holding the bottle upright on a flat surface. Follow the manufacturer’s directions to use and clean the oral syringe. Sildenafil Viagra is used to treat erectile dysfunction impotence; inability to get or keep an erection in men. · Viagra is used as needed, meaning you only take a dose prior to sexual activity. Cialis can be prescribed for use as needed, but can also be prescribed for use once per day, every day (without. As an alternative to Viagra, a person may wish to try any of the following: Alternative oral drugs: Including vardenafil, tadalafil, and avanafil. Nonoral drugs: Such as penile self injections. Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed about 1 hour.