the lining of your esophagus. for many, prescription nexium not only provides 24-hour heartburn relief, but can also help heal acid-related erosions in the lining of your esophagus. there is risk of bone fracture and low magnesium levels. side effects may include headache, abdominal pain and diarrhea. call your doctor right away if you have persistent diarrhea. other serious stomach conditions may exist. don't take nexium if you take clopidogrel. let your doctor do his job. and you do yours. ask if nexium is right for you. if you can't afford your medication, astrazeneca may be able to help.