Fildena 25 is a medication used for the treatment of erectile dysfunction (ED) in men. It contains the active ingredient sildenafil citrate, which works by increasing blood flow to the penis to help achieve and maintain an erection.

In terms of long-term safety and effectiveness, several studies have shown that Fildena 25 and other sildenafil-containing medications can be effective for treating ED in the long-term. One study published in the Journal of Sexual Medicine found that after 5 years of treatment with sildenafil, 79% of men with ED reported improved erectile function.

In terms of safety, long-term use of sildenafil has been associated with a low risk of adverse effects. A study published in the International Journal of Impotence Research found that after 4 years of treatment with sildenafil, only 2% of men experienced adverse effects that led to treatment discontinuation.

However, it's important to note that sildenafil-containing medications like Fildena 25 are not appropriate for everyone. They should not be taken by men who are taking nitrates for chest pain or by men who have certain medical conditions such as severe liver or kidney disease, low blood pressure, or a history of heart attack or stroke.

As with any medication, it's important to discuss the potential risks and benefits of Fildena 25 with a healthcare provider before starting treatment, and to follow the prescribed dosage and instructions for use.