Rarely reported side effects include: an erection that will not go away priapism. Some medications should not be taken with sildenafil. Children—Use is not recommended. Which Is More Effective? Common ones include: Flushing of the skin.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP. Viagra Dosage and Use Tips for First-Timers. Viagra dosage for erectile dysfunction (ED) is usually milligrams (mg), but those over 65 may start at 25 mg. Your doctor will also need to.  · Teva sildenafil is a generic version of Viagra used to treat erectile dysfunction (ED) and some heart conditions. Learn about Teva sildenafil and how to use it. 50 mg; mg; It also comes as.