If i had an adverse reaction to gabapentin for pain am i likely to suffer the same fate with cymbalta (duloxetine)? i know they work differently but still worried

Not necessarily: Cymbalta (duloxetine) and gabapentin are different classes of medications with different side effects. However, good to tell prescribing doctor about medications you did not tolerate and why. Some people are more sensitive in general to meds. Keep track of your responses. Discuss your concern with prescribing doctor. Ask what side effects might occur and what to do in that event. Take care.