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Completed

NCT Number: NCT03205787

Red Clover Botanical Dietary Supplements - Metabolism and Safety in Women

Human safety studies were carried out to test whether red clover botanical dietary supplements used by peri- and post-menopausal women are safe to use with Food and Drug Administration (FDA)-approved drugs. To test this, a red clover dietary supplement (previously tested in women at the University of Illinois at Chicago without any harmful effects) was given with four selected FDA-approved drugs to determine if the red clover supplement can increase or decrease how these medications are absorbed, metabolized and excreted by the human body. Preclinical studies predicted that the red clover supplement might affect the metabolism or break down of these probe drugs.

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Key information

Conditions

Food-drug Interaction

Age range

40 year–79 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Primary location

University of Illinois at Chicago

Chicago, Illinois, 60612, United States

About this study

At the start of a study, subjects were administered low doses of a mixture of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam), and serial blood samples were drawn and analyzed for the concentration of each drug over time. Afterwards, participants took the red clover dietary supplement twice orally daily for 14 days to allow for potential inhibition or induction of drug metabolizing enzymes and transporters. Thereafter, the same drugs were taken again to obtain a second measure of drug concentrations in blood over time. Changes in the concentration-time curve values for each probe drug obtained before and after ingestion of the supplement were evaluated to determine if metabolism of the probe drugs was impacted by the red clover dietary supplement.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • healthy peri- and post-menopausal women ages 40 - 79
  • non-smokers
  • no-significant medical conditions as assessed by subject-reported medical history, physical examination and blood and urine chemistry screens
  • no medical condition that requires chronic use of medication

Exclusion criteria

  • known allergies or hypersensitivity to caffeine, dextromethorphan, sulfonylureas (tolbutamide), benzodiazepines, or red clover
  • positive pregnancy test
  • use of hormone therapy within 8 weeks of study initiation for oral agents, 4 weeks for transdermal or other topical agents
  • use of caffeine products 7 days before study participation or during the study
  • use of citrus products 7 days before study participation or during the study
  • other prescription (with the exception of the Mirena® IUD) or non-prescription medicines within the 2 weeks prior to study initiation or during the study
  • chronic diseases, such as inflammatory bowel disease, that could alter the absorption or metabolism of the probe substrates
  • unwillingness to comply with study requirements
  • current participation in another clinical trial
  • CYP2D6 deficiency based on phenotyping at screening
  • smoker
  • red clover or soy intake (whether as a botanical dietary supplement, food, drink or otherwise) within the previous two weeks and during the study
  • use of any dietary supplements within the last 2 weeks prior to study initiation and during the study
  • extreme obesity (defined as >40 BMI)
  • alcohol or drug abuse
  • chronic diseases such as diabetes.

Treatment and study plan

Trifolium pratense

Dietary Supplement

Red Clover extract standardized to isoflavone content.

Other names: Red Clover

Primary outcomes

  1. Area Under the Curve (AUC)

    Time frame: baseline and 14 days

    Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate areas under the (extrapolated) concentration-time curve to determine any changes compared to pre-intervention.

Secondary outcomes

  1. Apparent Clearance

    Time frame: baseline and 14 days

    Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in apparent clearance of each probe drug compared to pre-intervention.

  2. Peak Concentration

    Time frame: baseline and 14 days

    Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in peak concentrations of probe drugs to compared to pre-intervention concentrations.

  3. Time for Peak Concentration

    Time frame: baseline and 14 days

    Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in time for peak concentration of probe drugs compared to pre-intervention concentrations.

  4. Drug Half-life

    Time frame: baseline and 14 days

    Concentrations of probe drugs from blood draws at the end of the 14-day intervention were used to calculate half-lives of probe drugs to determine any changes compared to pre-intervention.

Sponsors and collaborators

Lead sponsor

University of Illinois at Chicago

Other

Registry information

Important dates

Study start
2017
Primary completion
2020
Study completion
2020
First posted
Jul 2, 2017
Registry last updated
May 6, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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