This guidance helps sponsors of investigational new drug applications and applicants of new drug applications evaluate drug-drug interactions (DDIs) during drug development and communicate the results and recommendations from DDI studies.

This guidance focuses on the conduct of clinical studies to evaluate the DDI potential of an investigational drug, including: (1) the timing and design of the clinical studies; (2) the interpretation of the study results; and (3) the options for managing DDIs in patients.

A related FDA draft guidance for industry entitled In Vitro Drug Metabolism- and Transporter-Mediated Drug-Drug Interaction Studies focuses on how to assess the DDI potential of a drug in vitro and how to use the results from those assessments to inform clinical DDI studies.
Together, these  two guidances on DDIs describe a systematic, risk-based approach for evaluating DDIs and communicating the results of DDI studies and will replace the 2012 draft guidance entitled Drug Interaction Studies – Study Design, Data Analysis, Implications for Dosing, and Labeling Recommendations


Clinical Drug Interaction Studies — Study Design, Data Analysis, and Clinical Implications