APA Dictionary of Psychology

a class of drugs that reduce the production of stomach acid by binding with the enzyme that causes the stomach’s parietal cells to secrete acid. These oral medications are commonly used to prevent and treat conditions such as dyspepsia, peptic ulcers, and gastroesophageal reflux disease, and they are usually well tolerated, although their effectiveness is variable. Possible side effects include headache, stomachache, nausea, dizziness, rash, constipation, and diarrhea. Both prescription and over-the-counter PPIs are available.