Proton pump inhibitors (PPIs) are the most potent drugs to inhibit gastric acid secretion, being used in the treatment of most inflammatory conditions of the gastric mucosa. They are among the most prescribed and overprescribed medications worldwide; for example, in the United States, according to the National Health and Nutrition Examination Survey, they almost doubled their use in adults aged 40 years and older from 4.9 % to 8.3 % between 1999 and 2012. Although they are generally considered well tolerated, some epidemiological studies extracting information from large databases have reported a number of adverse effects associated with their prolonged use, including cognitive impairment, chronic kidney disease, myocardial infarction, stroke, bone fractures and even death, among others. The objective was to conduct a narrative review of the literature on the effects of chronic use of PP...