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# Guide on Gastric pH-Dependent Drug Interactions
- URL: https://www.fdaweb.com/guide-on-gastric-ph-dependent-drug-interactions/
- Published: 2020-12-01T12:00:00.000Z
- Updated: 2026-09-14T16:38:23.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5148195

*Federal Register* notice: FDA has made available a draft guidance entitled *Evaluation of Gastric pH-Dependent Drug Interactions With Acid-Reducing Agents: Study Design, Data Analysis, and Clinical Implications*. The document focuses on specific recommendations pertinent to gastric pH-dependent drug-drug interaction (DDI) assessments and describes the agency’s recommendations regarding when clinical DDI studies with acid-reducing agents are needed; the design of the clinical studies; the interpretation of study results; and communicating findings and options for managing pH-dependent DDIs in product labeling. To view the notice, click [here](https://www.govinfo.gov/content/pkg/FR-2020-12-01/pdf/2020-26510.pdf?ref=fdaweb.com).