HealthyPhase 4NCT00006395
Drug Interaction Study of Tegretol (Carbamazepine) and St. John's Wort in Normal Volunteers
A Phase 4 study testing St. John's Wort in people with Healthy, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
Trial summary
St. John's Wort is a popular dietary supplement that many patients-including those with epilepsy or seizures-take in addition to their regular medicines to elevate mood or relieve stress. Read more about this study
- Who is it for?
- Any ageHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- St. John's Wort
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- Oct 2000to Apr 2001
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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 Any age
- All sexes
- Healthy volunteers accepted
- Child, Adult, Older adult
Male or female.
Healthy by medical history and physical exam.
Age between 21 and 65 years old.
Non-smoker for a minimum of 6 months.
AST/SGOT less than or equal to 2 x upper limit of normal.
Serum creatinine less than or equal to upper limit of normal.
Hemoglobin greater than or equal to 10 g/dl.
Females of childbearing potential must be using a reliable form of birth control other than hormonal contraceptives.
No concomitant therapy with other inhibitors or inducers of cytochrome P-450 mediated drug metabolism within 30 days of study.
No inability to remain free of chronic medications and alcohol for at least 2 weeks prior to and during the study.
No previous use of St. John's Wort. Subjects with prior history of St. John's Wort use must abstain from use for 30 days prior to study participation.
No presence of renal, hepatic, cardiovascular, hematologic, neurologic, psychiatric, or respiratory disease or any other condition that may interfere with the interpretation of the study results or not be in the best interests of the subject in the opinion of the investigator.
No positive urine pregnancy test.
No presence of persistent diarrhea or malabsorption that would interfere with the patients ability to adequately absorb drugs.
Trial locations and contacts
1 site in 1 country.
United States1 site
Warren G. Magnuson Clinical Center (CC)
Bethesda, Maryland, 20892
About this study
Official title: Evaluation of the Effect of St. John's Wort on Single Dose Carbamazepine Pharmacokinetics in Normal Healthy Volunteers
St. John's Wort is a popular dietary supplement that many patients-including those with epilepsy or seizures-take in addition to their regular medicines to elevate mood or relieve stress. Preliminary research indicates that this supplement can speed the metabolism of the anti-seizure drug Tegretol, causing reduced blood levels of the drug. Patients who take Tegretol to control their seizures may have more frequent seizures if the blood level of the drug drops too low. A recent study shows that this effect is not seen when Tegretol is taken for at least 3 weeks. The present study will examine whether there is a medically important drug interaction between St. John's wort and Tegretol when Tegretol is taken for 1 day.
Normal healthy volunteers between 21 and 65 years old who are not taking medicines that can affect the metabolism of drugs in the liver and have not used St. John's wort for at least 30 days may be eligible for this 25-day study.
Read more
Participants will take a 400-mg dose of Tegretol after fasting overnight. Blood samples will be drawn the next day during a 12-hour clinic stay at the following intervals: just before the Tegretol dose and at 1, 2, 4, 6, 8, 10, 24, 34, 48 and 72 hours after the dose. A catheter will be placed in the vein to prevent the need for multiple needle sticks until after the 10-hour sample. After completing the blood sampling, participants will take 300 mg of St. John's wort 3 times a day with meals for 2 weeks. After 2 weeks, another fasting dose of Tegretol will be given and the 72-hour blood study will be repeated.
This study may provide information important for the care of patients with epilepsy who take both Tegretol and St. John's Wort.
Read the detailed description
Alternative or complementary therapies are widely used by patients with epilepsy. St. John's Wort is one of the most popular herbal dietary supplements with a variety of claims including mood elevation and stabilization, stress relief, anti-viral effects, and enhancement of the immune system. We have previously demonstrated that treatment with St. John's Wort for 14 days does not induce the clearance of carbamazepine under steady state conditions of autoinduction of carbamazepine clearance. One proposed mechanism for this lack of effect is that St. John's Wort is not sufficiently potent to further induce previously induced CYP3A4 enzyme activity. The purpose of this study is to investigate the effect of St. John's Wort on single dose carbamazepine pharmacokinetics under conditions of uninduced CYP3A4. To evaluate this potential drug interaction, as well as the effect of St. John's Wort on epoxide hydrolase activity, eight normal healthy subjects will be enrolled into this pharmacokinetic study. Subjects will take a single 400 mg dose of carbamazepine followed by serial blood sampling over 72 hours for carbamazepine and carbamazepine epoxide plasma concentrations. Subjects will then begin taking a standardized formulation of St. John's Wort three times daily with meals for two weeks. Following 2 weeks of St. John's Wort subjects will then again take a single 400 mg dose of carbamazepine and have serial blood samples collected for carbamazepine and carbamazepine epoxide plasma concentrations. The total carbamazepine and carbamazepine epoxide exposure (AUC), oral clearance (CL/F), and maximal concentrations (Cmax) will be compared between treatment phases to characterize the potential drug interaction.
- Conditions
- Healthy
- Being tested
- St. John's Wort
- Keywords
- Antiepileptic, CYP3A4, Herbal, Induction, Interaction
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
St. John's WortDrug
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Dec 2002 (estimated)
- Study startOct 2000
- Study completionApr 2001
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for HealthyStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Enrolment
- 12 participants
Sponsor and investigators
- Lead sponsor
- National Institutes of Health Clinical Center (CC)
- Sponsor type
- US National Institutes of Health
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00006395
- Sponsor's protocol ID
- 010005
- Other IDs
- 01-CC-0005
- Status last verified
- Sep 2000
- First submitted
- 7 Oct 2000
- Last updated
- 4 Mar 2008
- Results posted
- No
Publications
Johne A, Brockmoller J, Bauer S, Maurer A, Langheinrich M, Roots I. Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (Hypericum perforatum). Clin Pharmacol Ther. 1999 Oct;66(4):338-45. doi: 10.1053/cp.1999.v66.a101944.
PubMed 10546917Ruschitzka F, Meier PJ, Turina M, Luscher TF, Noll G. Acute heart transplant rejection due to Saint John's wort. Lancet. 2000 Feb 12;355(9203):548-9. doi: 10.1016/S0140-6736(99)05467-7.
PubMed 10683008Israel D, Youngkin EQ. Herbal therapies for perimenopausal and menopausal complaints. Pharmacotherapy. 1997 Sep-Oct;17(5):970-84.
PubMed 9324185
Study at a glance
From the registry record, last updated by the sponsor on 4 Mar 2008. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Effect of St. John's Wort on Single Dose Carbamazepine Pharmacokinetics in Normal Healthy Volunteers
- ClinicalTrials.gov ID
- NCT00006395
- Acronym / sponsor ID
- 010005
- Conditions
- Healthy
- Keywords
- Antiepileptic, CYP3A4, Herbal, Induction, Interaction
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants
- Lead sponsor
- National Institutes of Health Clinical Center (CC)US National Institutes of Health
- Study start
- Oct 2000
- Study completion
- Apr 2001
- First posted
- 10 Dec 2002 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
St. John's Wort is a popular dietary supplement that many patients-including those with epilepsy or seizures-take in addition to their regular medicines to elevate mood or relieve stress. Preliminary research indicates that this supplement can speed the metabolism of the anti-seizure drug Tegretol, causing reduced blood levels of the drug. Patients who take Tegretol to control their seizures may have more frequent seizures if the blood level of the drug drops too low. A recent study shows that this effect is not seen when Tegretol is taken for at least 3 weeks. The present study will examine whether there is a medically important drug interaction between St. John's wort and Tegretol when Tegretol is taken for 1 day.
Normal healthy volunteers between 21 and 65 years old who are not taking medicines that can affect the metabolism of drugs in the liver and have not used St. John's wort for at least 30 days may be eligible for this 25-day study.
Participants will take a 400-mg dose of Tegretol after fasting overnight. Blood samples will be drawn the next day during a 12-hour clinic stay at the following intervals: just before the Tegretol dose and at 1, 2, 4, 6, 8, 10, 24, 34, 48 and 72 hours after the dose. A catheter will be placed in the vein to prevent the need for multiple needle sticks until after the 10-hour sample. After completing the blood sampling, participants will take 300 mg of St. John's wort 3 times a day with meals for 2 weeks. After 2 weeks, another fasting dose of Tegretol will be given and the 72-hour blood study will be repeated.
This study may provide information important for the care of patients with epilepsy who take both Tegretol and St. John's Wort.
Detailed description
Alternative or complementary therapies are widely used by patients with epilepsy. St. John's Wort is one of the most popular herbal dietary supplements with a variety of claims including mood elevation and stabilization, stress relief, anti-viral effects, and enhancement of the immune system. We have previously demonstrated that treatment with St. John's Wort for 14 days does not induce the clearance of carbamazepine under steady state conditions of autoinduction of carbamazepine clearance. One proposed mechanism for this lack of effect is that St. John's Wort is not sufficiently potent to further induce previously induced CYP3A4 enzyme activity. The purpose of this study is to investigate the effect of St. John's Wort on single dose carbamazepine pharmacokinetics under conditions of uninduced CYP3A4. To evaluate this potential drug interaction, as well as the effect of St. John's Wort on epoxide hydrolase activity, eight normal healthy subjects will be enrolled into this pharmacokinetic study. Subjects will take a single 400 mg dose of carbamazepine followed by serial blood sampling over 72 hours for carbamazepine and carbamazepine epoxide plasma concentrations. Subjects will then begin taking a standardized formulation of St. John's Wort three times daily with meals for two weeks. Following 2 weeks of St. John's Wort subjects will then again take a single 400 mg dose of carbamazepine and have serial blood samples collected for carbamazepine and carbamazepine epoxide plasma concentrations. The total carbamazepine and carbamazepine epoxide exposure (AUC), oral clearance (CL/F), and maximal concentrations (Cmax) will be compared between treatment phases to characterize the potential drug interaction.
Study design
- Primary purpose
- Treatment
Who may qualify
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult, Older adult
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| St. John's Wort | Drug | – |
Primary outcome
Not reported in the source record.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Mar 2008.
- Background: PubMed 10546917Johne A, Brockmoller J, Bauer S, Maurer A, Langheinrich M, Roots I. Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (Hypericum perforatum). Clin Pharmacol Ther. 1999 Oct;66(4):338-45. doi: 10.1053/cp.1999.v66.a101944.
- Background: PubMed 10683008Ruschitzka F, Meier PJ, Turina M, Luscher TF, Noll G. Acute heart transplant rejection due to Saint John's wort. Lancet. 2000 Feb 12;355(9203):548-9. doi: 10.1016/S0140-6736(99)05467-7.
- Background: PubMed 9324185Israel D, Youngkin EQ. Herbal therapies for perimenopausal and menopausal complaints. Pharmacotherapy. 1997 Sep-Oct;17(5):970-84.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing St. John's Wort in people with Healthy, run by National Institutes of Health Clinical Center (CC) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Mar 2008. 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 United States. 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.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00006395, which also lists 3 linked publications.
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 4 Mar 2008.