Potential for interactions between dietary supplements and prescription medications

Am J Med. 2008 Mar;121(3):207-11. doi: 10.1016/j.amjmed.2007.11.014.

Abstract

Purpose: The objective of this study was to assess the frequency of clinically significant interactions caused by concurrent use of dietary supplements and prescription medication.

Methods: We conducted a cross-sectional, point-of-care survey and combined the findings with a review of patient medical records. Patients treated at Mayo Clinic (Rochester, Minn) in 6 different specialty clinics were surveyed for their use of dietary supplements. Concurrent use of prescription medications was obtained from patients' medical records. We used the Lexi-Interact online medication and dietary supplement interaction analysis program to assess the potential clinical significance of each interaction.

Results: We surveyed 1818 patients; 1795 responded (overall response rate of 98.7%) and 710 (39.6%) reported use of dietary supplements. In total, 107 interactions with potential clinical significance were identified. The 5 most common natural products with a potential for interaction (garlic, valerian, kava, ginkgo, and St John's wort) accounted for 68% of the potential clinically significant interactions. The 4 most common classes of prescription medications with a potential for interaction (antithrombotic medications, sedatives, antidepressant agents, and antidiabetic agents) accounted for 94% of the potential clinically significant interactions. No patient was harmed seriously from any interaction.

Conclusions: A small number of prescription medications and dietary supplements accounted for most of the interactions. The actual potential for harm was low.

MeSH terms

  • Adult
  • Aged
  • Cross-Sectional Studies
  • Data Collection
  • Dietary Supplements*
  • Drug Interactions*
  • Drug Prescriptions*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Surveys and Questionnaires