Note the fact that fildena 150 mg is ineffective in the absence of natural sexual arousal. As a result, take the drug 15-60 minutes before a sexual encounter and enjoy a strong erection for more than 4 hours. fildena 150 mg can be taken with or without food, and its effectiveness will not be diminished in any way. Sildenafil 150 mg every 24 hours should not be used unless directed by your physician.