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# 2 Guides on Drug Interaction Studies
- URL: https://www.fdaweb.com/2-guides-on-drug-interaction-studies/
- Published: 2020-01-24T12:00:00.000Z
- Updated: 2026-09-14T15:59:59.000Z
- Author: David McFarland
- Tags: FDA Policy/General, #legacy-id-D5145917

*Federal Register* notice: FDA has made available two final guidances entitled “Clinical Drug Interaction Studies — Cytochrome P450 Enzyme- and Transporter-Mediated Drug Interactions” and “In Vitro Drug Interaction Studies — Cytochrome P450 Enzyme- and Transporter-Mediated Drug Interactions.” The guidances are intended to assist drug developers in evaluating drug-drug interaction (DDIs) potential during drug development and describe a systematic, risk-based approach to assessing DDIs. To view the notice, click [here](https://www.govinfo.gov/content/pkg/FR-2020-01-23/pdf/2020-01064.pdf?ref=fdaweb.com).