• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services


  • Print
  • Share
  • E-mail

Drug Interactions & Labeling

Drug-drug interactions can lead to changed systemic exposure, resulting in variations in drug response of the co-administered drugs. In addition to co-administration of other drugs, concomitant ingestion of dietary supplements or citrus fruit or fruit juice could also alter systemic exposure of drugs, thus leading to adverse drug reactions or loss of efficacy. Therefore, it is important to evaluate potential drug interactions prior to market approval as well as during the postmarketing period.

This Web page provides drug developers with FDA's current understanding of how to conduct drug-interaction studies and resulting labeling.