Fildena 100 mg works by inhibiting the action of the enzyme phosphodiesterase type 5 (PDE5). This enzyme is responsible for the breakdown of cyclic guanosine monophosphate (cGMP), a chemical that plays a crucial role in relaxing smooth muscles in the penis. By inhibiting PDE5, Fildena 100mg allows the accumulation of cGMP, which increases blood flow to the penis during sexual stimulation, resulting in a firm and sustained erection. It is essential to use Fildena 100 mg as recommended by a healthcare professional. The medication is usually taken orally with a full glass of water, approximately 30 minutes before sexual intercourse. It is essential to note that Fildena 100 mg only works in response to sexual stimulation.