Licorice Botanical Dietary Supplements - Metabolism and Safety in Women

Human safety studies will be 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) will be given with four selected FDA-approved drugs to determine if the Licorice supplement can increase or decrease how these medications are absorbed, metabolized and excreted by the human body. Preclinical studies predict that the licorice supplement might affect the metabolism or break down of these probe drugs.

Study Overview

• Status: Completed
• Conditions: Food-drug Interaction
• Intervention / Treatment: Dietary supplement: Licorice; Drug: Alprazolam 2 MG; Drug: Caffeine 100 MG; Drug: Tolbutamide 250 mg; Drug: Dextromethorphan 30mg

Detailed Description

At the start of a study, subjects will be administered low doses of a mixture of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam), and serial blood samples will be drawn and analyzed for the concentration of each drug over time. Afterwards, participants will take the licorice dietary supplement twice daily for 14 days to allow for potential inhibition or induction of drug metabolizing enzymes and transporters. Thereafter, the same drugs will be 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 would indicate that metabolism of the probe drugs is impacted by the licorice dietary supplement.

• Study Type: Interventional
• Enrollment (Actual): 19
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Chicago, Illinois, United States, 60612
      • University of Illinois at Chicago

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 79 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

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 licorice
• 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
• licorice (whether as a botanical dietary supplement, candy, 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.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: G.Glabra; single arm

Dietary supplement: Licorice; Experimental :G. glabra Licorice extract: 2 gelatin capsules (75 mg) per day for 14 days; Other Names: G. glabra; Drug: Alprazolam 2 MG; probe substrate; Other Names: CYP3A4/5 substrate; Drug: Caffeine 100 MG; probe substrate; Other Names: CYP1A2 substrate; Drug: Tolbutamide 250 mg; probe substrate; Other Names: CYP2C9 substrate; Drug: Dextromethorphan 30mg; probe substrate; Other Names: CYP2D6 substrate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
1. Area Under the Curve (AUC)	Concentration of probe drugs from blood draws during the 14-day intervention will be used to calculate area under the (extrapolated) concentration-time curve to determine any changes compared to pre-intervention.	baseline and 14 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
1. Apparent Clearance	Concentration of probe drugs from blood draws during the 14-day intervention will be used to calculate apparent clearance of probe drug to determine any changes compared to pre-intervention.	baseline and 14 days
2. Peak Concentration	Concentration of probe drugs from blood draws during the 14-day intervention will be used to calculate peak concentration of probe drug to determine any changes compared to pre-intervention.	baseline and 14 days
3. Time for Peak Concentration	Concentration of probe drugs from blood draws during the 14-day intervention will be used to calculate time for peak concentration of probe drug to determine any changes compared to pre-intervention.	baseline and 14 days
4. Drug Half-life [Time Frame: baseline and 14 days]	Concentration of probe drugs from blood draws during the 14-day intervention will be used to calculate half-life of probe drug to determine any changes compared to pre-intervention.	baseline and 14 days

Collaborators and Investigators

• Sponsor: University of Illinois at Chicago
• Collaborators: Oregon State University

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2019
• Primary Completion (Actual): July 31, 2020
• Study Completion (Actual): April 22, 2022

Study Registration Dates

• First Submitted: May 8, 2019
• First Submitted That Met QC Criteria: May 10, 2019
• First Posted (Actual): May 13, 2019

Study Record Updates

• Last Update Posted (Estimate): May 5, 2023
• Last Update Submitted That Met QC Criteria: May 3, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: Licorice
• Additional Relevant MeSH Terms: Hypoglycemic Agents; Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Enzyme Inhibitors; Excitatory Amino Acid Antagonists; Excitatory Amino Acid Agents; Purinergic Antagonists; Purinergic Agents; Tranquilizing Agents; Psychotropic Drugs; Hypnotics and Sedatives; Anti-Anxiety Agents; GABA Modulators; GABA Agents; Respiratory System Agents; Phosphodiesterase Inhibitors; Purinergic P1 Receptor Antagonists; Central Nervous System Stimulants; Antitussive Agents; Dextromethorphan; Caffeine; Alprazolam; Tolbutamide
• Other Study ID Numbers: 2019-0115

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No