PROTON PUMP INHIBITORS: Study Finds Growing Reason to Be Wary of Some Reflux Drugs. “Older people should probably pay special heed. They are more likely to experience reflux, Dr. Semla explained, in part because the muscle that prevents stomach acid from rising into the esophagus weakens with age. Older adults are therefore more likely to take these drugs, and also more vulnerable to the diseases and disorders associated with them, especially with long-term use.”