Is There a Pharmacokinetic Interaction Between St John's Wort and Metformin?
Trial Snapshot
- Phase
- Phase 1
- Status
- Completed
- Enrollment
- 20
- Locations
- 1
- Primary Endpoint
- Change in Area Under Curve (AUC) 0-24h of metformin
Study Overview
Brief Summary
The goal of the study is to examine the difference of the pharmacokinetics of metformin with and without a 3 weeks pretreatment of St John's Wort. Furthermore secondary objectives include changes in GLP-1, C-peptide, serum-insulin and plasma-glucose during an oral glucose tolerance test, changes in OCT1 mRNA in plasma and changes in leptin and lipid-profile following this possible interaction.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Masking
- None
Eligibility Criteria
- Ages
- 18 Years to 64 Years (Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Men aged 18-64 years
- •Homozygous for common genetic variants in the genes organic cation transporter 1/2 (OCT1/OCT2)
- •Normal values of biomarkers accounting for: Liver and kidney function, and normal blood glucose
Exclusion Criteria
- •Chronic alcohol abuse
- •Hypersensitivity to metformin or St John's Wort
- •Daily intake of drugs requiring prescription
Arms & Interventions
Metformin
7 days of pretreatment with metformin before full pharmacokinetics and other goals are investigated.
Minimum 1 week of washout after this period. 3 weeks of pretreatment with St John's Wort and the last 7 days metformin is ingested again, and the same effect parameters as described above is performed again
Intervention: St John's Wort (Other)
Metformin
7 days of pretreatment with metformin before full pharmacokinetics and other goals are investigated.
Minimum 1 week of washout after this period. 3 weeks of pretreatment with St John's Wort and the last 7 days metformin is ingested again, and the same effect parameters as described above is performed again
Intervention: Metformin (Drug)
Outcomes
Primary Outcomes
Change in Area Under Curve (AUC) 0-24h of metformin
Time Frame: Concentration of metformin at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 12, 24 hours after metformin ingestion
Change in 0-24h AUC of metformin after 3 weeks of treatment with St John's Wort
Secondary Outcomes
- Pharmacokinetics of metformin(Concentration of metformin at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 6, 8, 12, 24 hours after metformin ingestion, which will be used to determine the pharmacokinetic parameters mentioned below)
- Change in messenger RiboNucleic Acid (mRNA)(Will be measured 4 times: At inclusion (t=0 on that day), at t=0 in both periods and minimum 3 weeks after finalization of the study (t=0 on that day))
- Oral glucose tolerance test (OGTT)(During the first 2 hours of each metformin ingestion)
Investigators
Tore B. Stage
M.Sc. Pharm
University of Southern Denmark