Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03772262 |
Other study ID # |
16620 |
Secondary ID |
U54AT008909 |
Status |
Completed |
Phase |
Early Phase 1
|
First received |
|
Last updated |
|
Start date |
April 5, 2018 |
Est. completion date |
March 31, 2019 |
Study information
Verified date |
April 2023 |
Source |
Washington State University |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
Goldenseal is a botanical natural product commonly used to self-treat symptoms of the common
cold and many digestive disorders. Goldenseal products typically contain the isoquinoline
alkaloids berberine, hydrastine, and hydrastinine. These constituents contain a
methylenedioxyphenyl ring, a 'structural alert' that can lead to irreversible inhibition of
drug metabolizing enzymes, particularly the cytochromes P450 (CYPs). Clinical studies
involving healthy volunteers demonstrated that, compared to baseline (absence of goldenseal),
CYP2D6 and CYP3A activities were reduced by 40-60% following treatment with goldenseal.
Compared to the CYPs, the effects of goldenseal products on drug transporters are
understudied, particularly in human subjects. Using a 'cocktail' consisting of 'probe' drug
substrates for CYP3A and various transporters, the effects of goldenseal on the
pharmacokinetics of each probe drug will be examined in healthy volunteers. Results will
provide useful information about the risk of co-consuming goldenseal with additional drugs
that are substrates for transporters.
Description:
Many patient groups often supplement their pharmacotherapeutic regimens with herbal and other
natural products (NPs), raising concern for adverse interactions with conventional drugs.
Unlike for drug-drug interactions, rigorous guidelines for assessing the risk of NP-drug
interactions do not exist. The NIH-funded Center of Excellence for Natural Product-Drug
Interaction (NaPDI) Research (U54 AT008909) was created in September, 2015. The mission of
the NaPDI Center is to provide leadership in the identification, evaluation, and
dissemination of potential clinically significant pharmacokinetic NP-drug interactions. One
over-arching goal of the Center is to develop a set of Recommended Approaches to guide
researchers in the proper conduct of NP-drug interaction studies. These Recommended
Approaches will be based on results generated from a series of Interaction Projects that will
include mechanistic human in vitro and clinical studies focused on four carefully selected
high priority NPs.
Using a systematic approach, the NaPDI Center selected four high priority NPs as precipitants
of NP-drug interactions. One of these NPs is goldenseal, which is typically used to
self-treat symptoms of the common cold, as well as numerous digestive disorders, both as a
single extract and in combination with other NPs, particularly Echinacea spp. Major
constituents of goldenseal include the isoquinoline alkaloids berberine, hydrastine, and
hydrastinine. These constituents contain a methylenedioxyphenyl ring, a 'structural alert'
that can lead to irreversible inhibition of drug metabolizing enzymes, particularly the
cytochromes P450 (CYPs). Indeed, clinical studies involving healthy volunteers demonstrated
that, compared to baseline (absence of goldenseal), CYP2D6 and CYP3A activities were reduced
by 40-60% following administration of ~1 g of a goldenseal extract three times daily for 14
or 28 days .
Compared to the CYPs, the effects of goldenseal products on drug transporters are
understudied, particularly in human subjects. A 'cocktail' consisting of 'probe' drug
substrates for CYPs and transporters is an efficient, cost-effective means to examine the
effects of a precipitant drug or NP on the pharmacokinetics of multiple object drugs
simultaneously. Such cocktails are used frequently by both academia and the pharmaceutical
industry to test for the interaction potential of new chemical entities, results of which are
often included in drug labels. A number of cocktails exist for the CYPs and have been used
successfully over the past 20+ years. A transporter cocktail was described recently that
consists of the probe drugs furosemide [organic anion transporter (OAT)1 and OAT3 substrate],
metformin [(organic cation transporter 2, multidrug and toxin extrusion protein (MATE)1, and
MATE2-K substrate)], and rosuvastatin [organic anion transporting polypeptide (OATP)1B1,
OATP1B3, and breast cancer resistance protein substrate].
Based on the multiple scientific gaps with respect to a commonly used NP, the purpose of this
healthy volunteer study is to assess the inhibitory effects of a well-characterized
goldenseal product on the pharmacokinetics of the aforementioned transporter probe drugs; the
CYP3A probe midazolam will be included to serve as a positive control object drug. Results
will be used to develop (1) a Recommended Approach regarding clinical study design of NP-drug
interactions and (2) mathematical models that can be used to predict the risk of potential
goldenseal-precipitated interactions with drugs whose pharmacokinetics are influenced by
CYP3A and/or transporters.