Safety issues associated with proton pump inhibitors (PPIs) have recently attracted widespread media and lay attention. Gastroenterologists are frequently asked about the appropriateness of PPI therapy for specific patients. Furthermore, some patients may have had PPI therapy discontinued abruptly or inappropriately due to safety concerns. Faced with such a wide variety of potentially serious adverse consequences, prescribers need to evaluate the evidence objectively to discern the likelihood that any reported association might actually be causal. Here, we review many of the proposed adverse consequences of PPI therapy and apply established criteria for the determination of causation. We also consider the potential contribution of residual confounding in many of the reported studies. Evidence is inadequate to establish causal relationships between PPI therapy and many of the proposed associations. Residual confounding related to study design and the overextrapolation of quantitatively small estimates of effect size have probably led to much of the current controversy about PPI safety. In turn, this has caused unnecessary concern among patients and prescribers. The benefits of PPI therapy for appropriate indications need to be considered, along with the likelihood of the proposed risks. Patients with a proven indication for a PPI should continue to receive it in the lowest effective dose. PPI dose escalation and continued chronic therapy in those unresponsive to initial empiric therapy is discouraged.

Hyperammonemia is a potentially fatal event occurring after orthotopic lung transplantation. It is associated with high nitrogen load, concurrent medical stressors, primary pulmonary hypertension, and hepatic glutamine synthetase deficiency.

Proton pump inhibitors (PPIs) have been widely used since their introduction in the late 1980s because they are highly effective for acid-related conditions. However, some recent epidemiological studies have suggested a positive association between PPI therapy and the risk of osteoporotic fractures. The potential mechanisms underlying this association may be related to the physiologic effects of chronic acid suppression on calcium metabolism. First, chronic hypergastrinemia induced by PPI therapy may lead to parathyroid hyperplasia, resulting in increased loss of calcium from the bone. Second, profound gastric acid suppression may reduce the bioavailability of calcium for intestinal absorption. I will review the published evidence regarding these potential links and discuss their clinical implications.

Hepatotoxicity after PRRT for metastatic GEP-NET is more common than previously reported.