Fildena Professional has generic alternatives because it is marketed as containing sildenafil citrate, the same active ingredient used in Viagra. The best alternative depends on the strength and tablet formulation. 

These products should not be assumed interchangeable unless the active ingredient, dose, and formulation match.

Safety: Sildenafil is generally prescribed  Fildena Professional  erectile dysfunction. Do not combine it with nitrate medicines such as nitroglycerin, and do not exceed the prescribed dose.

Which strength of Fildena Professional do you use—50 mg or 100 mg? I can narrow down the equivalent options.