My Husband Is Currently Waiting For Surgury On His Rotator

My husband is currently waiting for surgury on his rotator cuff tear and his doctor noticed histwitching and is having him take a ner study on the 29th before he'll do surgury. He prescribed Gabapentine and has been on it appx 9 days. Hisleft foot in the past two days has swollen and is bright red in spotches and looks as if its bleeding on inside. also itches. side affects?