Similar to Viagra, Fildena belongs to the class of drugs known as PDE5 inhibitors. Fildena 100 purple pill is the brand name for a variety of drugs made by Fortune Healthcare in India. Fildena is a treatment for men who struggle to get an erection that lasts as long as they’d like. If you want to have sexual activity with your partner, you should take Fildena 100 mg pills. Because of its delayed onset of action (anything from 30 minutes to an hour) and long duration of effect (up to four hours), Fildena is best taken an hour before engaging in sexual activity.