Fildena XXX 100mg is a sildenafil-based medicine used to treat erectile dysfunction (ED) in adult men. Sildenafil belongs to the PDE5 inhibitor class and works by increasing blood flow to the penis during sexual stimulation, helping support an erection. Fildena XXX 100mg does not increase sexual desire and will not cause an erection without sexual stimulation. It should be used only according to a healthcare professional's guidance. Common side effects may include headache, flushing, indigestion, dizziness, nasal congestion, and temporary visual changes. Sildenafil should not be taken with nitrate medicines because the combination can cause a potentially dangerous decrease in blood pressure.