question: Hi there. My son has been prescribed novo -lexin ( cephalexin) 500mg for a pressure sore he developed during hip reconstruction. He s already been taking it for 2 months and needs to continue until the sore is healed, which will be many months from now. What can I do to make sure he doesn t get the upset stomach he gets all the time. He s up all night long because of cramps or stomach discomfort. Please help.