Fildena 100 mg is another dosage form of the medication used to treat erectile dysfunction (ED). It contains sildenafil citrate, the same active ingredient found in Viagra. Fildena 100 mg helps to improve blood flow to the penis, facilitating an erection in response to sexual stimulation. sildenafil for treating ED is often 50 mg, but depending on individual response and tolerability, it can be increased to 100 mg. This is the dose found in Fildena 100 mg. Common side effects include headaches, flushing, indigestion, nasal congestion, and dizziness. More severe side effects could involve sudden changes in vision or hearing, chest pain, or prolonged erections (priapism).