I never had a panic attack till i had a bad reaction to nucynta (tapentadol).now every once in a while when take pills i have to fight off a panic attack. normal?

Yes indeed, however: Panic episodes are very common and can be responses to an original experience. However they frequently are precursors of an ailment known as panic disorder, even depression. If you are having other symptoms, sleep, mood, pleasure, weight, sleep, energy, concentration or if the panics are becoming more frequent speak to your doctor.