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Drug InteractionsNCT01258504

Influence of CYP3A4-induction by St. John's Wort on the Steady State Pharmacokinetics of Bosentan

An observational study of Drug Interactions, run by Gerd Mikus at 1 site in Germany.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The aim of the present study is to assess the impact of the cytochrome P450 2C9 (CYP2C9) genotype (*2 and *3 allele versus wild type; ~3-5% poor metabolisers in Caucasian population) on the pharmacokinetics of bosentan and the impact of CYP3A4-induction by St. Read more about this study

Who is it for?
Ages 18 to 65 yearsHealthy volunteers can take part
Conditions the study is for
Drug Interactions
What is being tested?
St. Johns Wort
How many people
13 participants
Where
1 siteGermany
Study dates
Jan 2011to Jun 2012
Phase
Observational
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 65 years
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Study population: healthy subjects

Who may be able to join

  • Good state of health (physically and mentally)
  • Able to communicate well with the investigator, to understand and comply with the requirements of the study
  • Voluntarily signed informed consent after full explanation of the study to the participant.
  • No clinically relevant findings in any of the investigations of the pre-study examination, especially aminotransferase elevations ≥ 3 × upper limit of normal(ULN). Minor deviations of other laboratory values from normal range may be acceptable, if judged by the investigator to be of no clinical relevance.
  • Known genotype for CYP2C9 polymorphism.
  • Agreement to abstain from alcoholic beverages during the time of the study.
  • Females must agree to use a reliable contraception (Pearl Index <1%), e.g. double barrier method.

Who cannot join

  • Any regular drug treatment within the last two months, except for oral contraceptives in female volunteers and L-thyroxine.
  • Any intake of a substance known to induce or inhibit drug metabolising enzymes or drug transporters within a period of less than 10 times the respective elimination half-life or 2 weeks, whatever is longer
  • Any participation in a clinical trial within the last month before inclusion
  • Any physical disorder which could interfere with the participant's safety during the clinical trial or with the study objectives
  • Any acute or chronic illness, or clinically relevant findings in the pre-study examination, especially: a) any condition, which could modify absorption, distribution, metabolism, or excretion of the drug regimen under investigation b) Allergies (except for mild forms of hay fever) or history of hypersensitivity reactions
  • Regular smoking
Show all 12Show fewer
  • Blood donation within 6 weeks before first study day
  • Excessive alcohol drinking (more than approximately 20 g alcohol per day)
  • Inability to communicate well with the investigator due to language problems or poor mental development
  • Inability or unwillingness to give written informed consent
  • Known or planned pregnancy or breast feeding
  • Pre-existing moderate or severe liver impairment

Trial locations and contacts

1 site in 1 country.

Germany1 site
  • University Hospital Heidelberg

    Heidelberg, 69120

Other trials in Germany

About this study

Official title: Influence of Cytochrome P450 3A4 (CYP3A4)-Induction by St. John's Wort (SJW) on the Steady State Pharmacokinetics of Bosentan

The aim of the present study is to assess the impact of the cytochrome P450 2C9 (CYP2C9) genotype (*2 and *3 allele versus wild type; ~3-5% poor metabolisers in Caucasian population) on the pharmacokinetics of bosentan and the impact of CYP3A4-induction by St. John's wort (SJW) on steady state bosentan which is a CYP3A4 inducer itself.

Read the detailed description

We evaluate the effect of SJW on bosentan pharmacokinetics and its relationship to polymorphisms in the CYP2C9 gene known to reduce CYP2C9 activity. This study will be conducted at bosentan steady-state because concentrations decrease in the first 10 days of treatment due to auto-induction of the metabolism.

Being tested
St. Johns Wort
Keywords
Steady-state, Bosentan, St. Johns Wort

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • St. Johns WortDrug

    Also called Jarsin

    • Administration of bosentan: 1 x 125 mg p.o. on days 1 and 20, 2 x 62.5 mg p.o. on day 2, 2 x 125 mg p.o. on days 3-19.
    • Administration of SJW: 3 x 300 mg daily p.o. on days 11-19 and 2 x 300 mg on day 20
Study groups in NCT01258504
Study groupRoleWhat they receive
CYP2C9 wild typeCYP2C9 wild type ="extensive metaboliser" * Administration of bosentan: 1 x 125 mg p.o. on days 1 and 20, 2 x 62.5 mg p.o. on day 2, 2 x 125 mg p.o. on days 3-19 * Administration of St. Johns Wort: 3 x 300 mg daily p.o. on days 11-19 and 2 x 300 mg on day 20
Receives: Drug: St. Johns Wort
CYP2C9 mutantCYP2C9 *2/*2 or 2*/*3 or *3/*3 = "poor metaboliser" * Administration of bosentan: 1 x 125 mg p.o. on days 1 and 20, 2 x 62.5 mg p.o. on day 2, 2 x 125 mg p.o. on days 3-19 * Administration of St. Johns Wort: 3 x 300 mg daily p.o. on days 11-19 and 2 x 300 mg on day 20
Receives: Drug: St. Johns Wort

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. AUC of Bosentan

    Measured: 0-infinity; during dosing interval

  2. Cmax of Bosentan

    Measured: after first dose, at steady-state and during SJW

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted13 Dec 2010 (estimated)
  2. Study startJan 2011
  3. Primary completionDec 2011
  4. Study completionJun 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Case-control
Time perspective
Prospective
Enrolment
13 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01258504
Sponsor's protocol ID
K330
Other IDs
2010-022328-64
Status last verified
May 2017
First submitted
10 Dec 2010
Last updated
31 May 2017
Data monitoring committee
No

Publications

  • Dingemanse J, van Giersbergen PL. Clinical pharmacology of bosentan, a dual endothelin receptor antagonist. Clin Pharmacokinet. 2004;43(15):1089-115. doi: 10.2165/00003088-200443150-00003.

    PubMed 15568889

Questions about this trial

What is this clinical trial studying?

An observational study of Drug Interactions, run by Gerd Mikus at 1 site in Germany.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 12 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 31 May 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 2 Jun 2015). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

AUC of Bosentan (time frame: 0-infinity; during dosing interval). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01258504, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 31 May 2017.

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