Spurs won the home leg of the last-16 tie 3-0 last week and Dembele has said that they need to go out and attempt to score an away goal.
"It won't be easy because Inter will be determined to beat us at home," Dembele told Tottenham's official website.
"We have to concentrate on being ourselves and go out there to win, not think about not losing 3-0 or anything like that.
"We have to play our normal game and if we score, that means they have to score five. It's all about going out with the right mentality."
Dembele has scored once in the Europa League this season.