All three conditions — gastric acidity, stomach upset, and heartburn — can be attributed to stomach acid as one of the underlying causes. Consequently, medications designed to regulate gastric acidity commonly treat these conditions. There are few over-the-counter medications (non-prescription medications) and few prescription medications available for treating the issue: Antacids, H2 Blockers, Proton Pump Inhibitors, Prokinetics, Alginates, and Coating Agents. Gastric acidity, upset stomach, and heartburn medication