Fildena 150 to work fast, place the pill under your tongue. This way, results can occur in as little as 30 minutes. It is essential to know that Fildena 150 can only be taken once every 24 hours. It is also important that you know that you should take it about an hour before s*xual activity. To get the most benefit from the drug, it is best taken on an empty stomach with a glass of water. Doctors recommend Fildena 150mg as the highest dose and Fildena 100mg as the lowest dose. Doctors usually recommend Fildena based on the patient's current medical condition, age, and severity of erectile dysfunction. Regardless of your age, it is best to use the lowest dose available.