Fildena (sildenafil) is generally 25 mg. Fildena is a brand of sildenafil used to treat erectile dysfunction (ED). 25 mg: Lowest commonly used oral dose. 50 mg: A common starting dose for many adults. 100 mg: Higher dose; generally the maximum recommended sildenafil dose for ED in  Fildena  The right dose depends on your health, other medications, and how you respond to treatment. A lower dose may be appropriate for some people, but follow a clinician’s advice. Important safety warning: Do not take sildenafil with nitrate medicines (such as nitroglycerin) or riociguat, because the combination can cause a dangerous drop in blood pressure. Never exceed one dose in 24 hours without medical direction.