Fildena Double 200 mg is marketed as a high-strength sildenafil product for erectile dysfunction (ED). Sildenafil belongs to a group of medicines called PDE5 inhibitors and works by increasing blood flow to the penis during sexual stimulation. However, a 200 mg dose is higher than the maximum recommended sildenafil dose in FDA-approved labeling. For erectile dysfunction, sildenafil is generally started at 50 mg, adjusted according to effectiveness and tolerability, and should not exceed 100 mg or be taken more than once a day.