Filitra is typically taken orally before anticipated sexual activity. It is important to follow the prescribed dosage and instructions provided by a healthcare professional. Vardenafil typically has a shorter duration of action compared to tadalafil, but it can still be effective for several hours. Like any medication, Filitra may cause side effects. Common side effects include headache, flushing, stuffy or runny nose, indigestion, and dizziness. Serious side effects are rare but may include priapism (prolonged and painful erection) and changes in vision or hearing.