Stomach acid serves a number of purposes in the digestive process. Stomach acid aids in food breakdown and also acts as a barrier to infection, the Harvard Medical School Family Health Guide states. Excess acid production can contribute to gastric ulcer formation and gastroesophageal reflux, the regurgitation of stomach acid into the esophagus. The lining of the esophagus, unlike the stomach lining, doesn't "repel" acid well. Reducing acid production helps improve these diseases. Medications with different actions can reduce acid production or neutralize its effects.
Histamine Blockers
Histamine or H2 blockers reduce the production of hydrochloric acid in the stomach. When histamine binds to histamine receptors, the receptors stimulate release of stomach acid. Blocking histamine decreases acid production. Histamine blockers--famotidine, sold as Pepcid AC; cimetidine, sold as Tagamet; and ranitidine, sold as Zantac--all come in over-the-counter and prescription forms. Taking histamine blockers in the evening or at bedtime increases their effectiveness. Histamine blockers may cause rash, fever and muscle pains. Men may develop gynecomastia, or breast enlargement, and erection difficulties.
Proton Pump Inhibitors
Proton pump inhibitors, or PPIs, shut down the pumps that produce stomach acid. These drugs--omeprazole, sold as Prilosec OTC; esomeprazole, sold as Nexium; pantoprazole, sold as Protonix; and lansoprazole, sold as Prevacid--are the most effective drugs for reducing stomach acid, the Merck Manuals Online Medical Library reports. Proton pump inhibitors may also inhibit H. pylori, the bacteria that often cause stomach ulcers. Side effects of PPIs include headache, constipation and diarrhea. Stopping PPIS can cause a rebound increase in production of the hormone gastrin, which can lead to an increase in stomach acid.
Antacids
While antacids don't reduce stomach acid production, they can neutralize the acid and relieve symptoms. Over-the-counter antacids--simethicone, sold as Maalox and Mylanta; aluminum hydroxide, sold as Alu-Cap or Alu-Tab; and magnesium hydroxide, sold as Milk of Magnesia--neutralize stomach acid and relieve stomach pain. Side effects include headache, nausea, vomiting and constipation or diarrhea. Aluminum hydroxide can cause calcium and phosphate loss, leading to weakness and appetite loss. People with kidney disease should take magnesium hydroxide only in small doses.
