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Systematic determination of the pharmacokinetic interactions of Echinacea purpurea with prescribed medications in healthy volunteers: A phase-I clinical trial using a cocktail approach

Systematic determination of the pharmacokinetic interactions of Echinacea purpurea with prescribed medications in healthy volunteers: A phase-I clinical trial using a cocktail approach - EchinaceaDDI

Status
Recruiting
Phases
Phase 1
Study type
Interventional
Source
DRKS
Registry ID
DRKS00017448
Enrollment
49
Registered
2020-01-16
Start date
2020-04-01
Completion date
Unknown
Last updated
2025-04-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

MedDRA - Drug-drug pharmacokinetic interaction

Interventions

Group 1: healthy participants (treated 21 days with Echinacea and 3 appointments for in-house phenotyping)

Sponsors

Universitätsklinikum Schleswig-Holstein (UKSH)
Lead Sponsor

Eligibility

Sex/Gender
All
Age
18 Years to 54 Years

Inclusion criteria

Inclusion criteria: 1. Subject gives informed consent by means of a personally signed and dated informed consent form (ICF) 2. Age 18-54 years

Exclusion criteria

Exclusion criteria: 1. Smoking 2. Participants who are genetically carriers of CYP2D6*3-6/*3-6, CYP2C9*2/*3 or *3/*3, CYP3A*22, CYP2C19*2/*2 or SLCO1B1*5/*5 3. Subjects currently enrolled in another clinical trial 4. Usage of medicinal products (prescription and OTC) during the study period, excluding non-hormonal contraceptives 5. Consumption of grapefruit and bitter orange during the study period 6. Consumption of alcohol, tea, herbal supplements or caffeine within 24 hours prior to and during each in-patient study day 7. Hypersensitivity, allergy or idiosyncratic reaction to the IMPs 8. Specific contraindication to the IMPs not covered by other exclusion criteria: 8.1. History of apnoea/respiratory insufficiency (midazolam, codeine) 8.2. History of myopathy (pitavastatin, rosuvastatin) 8.3. History of immune disorders/atopy or tuberculosis/sarcoidosis (Echinacea) 8.4. Known CYP2D6-ultra-rapid-phenotype (codeine) 8.5. Known risk factors for bleeding like gastrointestinal lesions, recent neurosurgery or damages to brain/spine, oesophageal varices, arteriovenous malformations (dabigatran) 9. History of coagulation disorders, abnormal clotting lab results or pharmaceutical anti-coagulation 10. Estimated Glomerular Filtration Rate < 80 ml/min 11. Known active hepatitis B or C infection, acute liver malfunction or abnormal liver lab results 12. Elevated creatinine kinase (as judged by the investigator) 13. Persistent diarrhea 14. Pregnancy and breastfeeding 15. Any other disease, condition or safety laboratory result which might compromise significantly the hematopoietic, renal, pulmonary, hepatic, cardiovascular, immunological, central nervous, dermatological, endocrinological or psychiatric or any other body system (as judged by the investigator) 16. Expected or suspected non-compliance, e.g., major cognitive or psychiatric disorders, drug usage 17. Subjects who are scheduled to undergo hospitalization during the study period 18. Legal incapacity 19. Women of child-bearing potential and not on highly-effective (Pearl-Index <1%) non-hormonal contraception 20. Medical students who are before or in a semester with pharmacological courses and examination at Kiel University

Design outcomes

Primary

MeasureTime frame
Changes in bioavailability (measured as AUC (parent)) after 20 days of Echinacea ingestion compared to baseline for dabigatran, pitavastatin and rosuvastatin (indicative for the activity of ABCB1, SLCO1B1 and ABCG2, resp. Changes in bioavailability (measured as AUC_parent) after 20 days of Echinacea ingestion compared to baseline for 6 drugs caffeine, midazolam, codeine, morphine, losartan, omeprazole (indicative for the activity of various cytochrome p450 enzymes). Statistical and clinical relevance is assumed when the 90% confidence interval of AUCinf(parent, baseline) / AUCinf(parent, after 20 days) is not within the no-effect-boundaries 0.8 – 1.25.

Secondary

MeasureTime frame
- Pinpointing changes of AUC to a specific metabolic pathway by analyzing changes in metabolic ratios (measured as AUC (parent)/AUC (metabolite)) after 20 days of Echinacea ingestion compared to baseline for 6 parent drug:metabolite pairs to estimate which enzyme might be responsible for the increased metabolic rate - Evaluation of limited sampling strategies - Full pharmacokinetic characterization of the probe drug cocktail - Time-course of induction - Echinaea plasma concentration - Safety profile

Countries

Germany

Contacts

Public ContactRuwen Böhm

Institut für Experimentelle und Klinische Pharmakologie, UKSH, Campus Kiel

ruwen.boehm@pharmakologie.uni-kiel.de0431 500 30414

Outcome results

None listed

Source: DRKS (via WHO ICTRP) · Data processed: Feb 4, 2026