The problem is, except for the most serious cases of reflux, these drugs are not meant for long-term or continual use. Over time, they can have negative side effects. Antacids can eventually upset the digestive tract and lead to diarrhea or constipation. Proton pump inhibitors like Prevacid and Prilosec, which are used to reduce the production of stomach acid, have been linked to increased risk of osteoporosis (brittle bone disease), pneumonia, and negative drug interactions.

http://iceconnect.org/acid-reflux-strategy-review/