Fildena 150 mg is one of the medications used to treat impotence and erectile dysfunction in men. Only men who are at least eighteen years old may take this drug. One of the ingredients in this drug, sildenafil, helps men achieve a strong erection during intercourse. Let this medication take effect 45 minutes before having sex. It takes four hours for this medication to start working. During sexual activity, this drug helps men get a strong erection. You can take this medication with or without food. This will slow down the side effects, so avoid combining it with cold drinks or fatty foods.