Proton Pump Inhibitors in Glioblastoma: From Reflexive Prescribing to Evidence-Based Practice.

Glucocorticoids are frequently used in the management of brain tumours to control tumour-associated cerebral oedema and symptoms related to mass effect. Because glucocorticoid exposure may increase the risk of upper gastrointestinal complications in selected patients, proton pump inhibitors (PPIs) are often prescribed prophylactically. Emerging evidence suggests that exposure to PPIs with potent aldehyde dehydrogenase 1A1-activating properties (PA-PPIs) such as omeprazole may be associated with worse progression-free and overall survival in newly diagnosed glioblastoma (GBM). Routine reflexive PPI prophylaxis may therefore not be justified. When acid suppression is clinically indicated, the choice of agent should be individualized, with consideration of H₂ receptor antagonists or antacids where appropriate. These findings support an acid-suppressive stewardship approach in the management of patients with GBM.