When taking a Fildena tablet, you must ensure that you do so before consuming any food. This medication can cause drowsiness or a loss of vision. It is important to take this drug with water, as it can lead to nausea and vomiting. The recommended dosage for Fildena is 100 mg. If you are taking a low dose, you may want to skip it. You can take the medication one hour before or after eating.