Which drug is safest for lifetime maintenance of gerd on daily basis: 40mg of omeprazole, 40mg protonix, or 40mg nexium (esomeprazole)?

Equivalent, but: These are all pretty equivalent. They are different drug formulations that work on the same general mechanism within the stomach to decrease acid secretion. It is important to note that long term use of these medications can be associated with osteoporosis. It is important to maintain recommended calcium/vitamin D intake and see Dr. for assessment of osteoporosis risk.