Drug Interactions of Echinacea, Ginseng, and Ginkgo Biloba Taken With Lopinavir/Ritonavir in Healthy Volunteers
Status:
Completed
Trial end date:
2011-06-01
Target enrollment:
Participant gender:
Summary
This study will examine the interaction of the HIV combination medication lopinavir/ritonavir
with the herbal products echinacea, ginseng, and ginkgo biloba. Patients with HIV infection
often take herbal products and dietary supplements in addition to their doctor-prescribed
medicines to treat the disease, lessen the side effects of anti-viral drugs, and improve
their overall well being. Alternative medicines such as these may, however, interfere with
the elimination of lopinavir/ritonavir from the body, causing either higher or lower blood
levels of these drugs than would be expected. This study will assess in healthy subjects any
potential harms of taking echinacea, ginseng, or ginkgo biloba together with
lopinavir/ritonavir.
Healthy normal volunteers between 18 and 50 years of age may be eligible for this study.
Candidates are screened with a history, physical examination, and blood tests, including an
HIV test and a pregnancy test for women. Pregnant women are excluded from the study.
Participants come to the NIH Clinical Center after fasting overnight for the following
procedures:
Visits 1 and 2: A catheter (plastic tube) is placed in an arm vein to collect blood samples.
After the first sample is drawn, the subject takes 8 mg of midazolam syrup and two
fexofenadine tablets. Midazolam is a sedative, and fexofenadine (Allegra) is a medicine used
to treat allergies. Subjects are given breakfast an hour after taking the drugs. Blood
samples are collected at 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 8 and 24 hours after taking
the drugs to measure blood levels of fexofenadine. An extra sample is collected at the 4-hour
mark to measure the midazolam level. The catheter is removed after the 8-hour blood draw and
subjects are dismissed home. They return the following morning (visit 2) for the 24-hour
blood draw.
Visit 3: From 7 to 28 days after visit 1, subjects begin taking lopinavir/ritonavir capsules
twice a day by mouth for a total of 29.5 days. On day 15 they return to the clinic for
lopinavir/ritonavir blood levels as were done for fexofenadine, except that samples are
collected once before breakfast and then at 0.5, 1, 2, 3, 4, 6, 8 and 12 hours after the
lopinavir/ritonavir dose. An extra sample is collected for routine tests. The catheter is
removed after the 12-hour draw and the subject is dismissed home.
The next morning, subjects begin taking one of the following: echinacea 500 mg 3 times a day;
ginkgo biloba 120 mg twice a day; or ginseng 500 mg 3 times a day for 28 days.
Visit 4: On the last day of taking lopinavir/ritonavir, subjects return to the clinic again
for blood level measurements of these drugs as on visit 3, except that the catheter is
removed and the subject dismissed home after the 8-hour blood draw.
Visits 5 and 6: On the last day of taking the herbal supplement, subjects return to the
clinic for repeat measurement of fexofenadine and midazolam levels, as described in visits 1
and 2. At the final visit (visit 6) an additional blood sample is collected for repeat
laboratory testing.
...
Phase:
Phase 4
Details
Lead Sponsor:
National Institutes of Health Clinical Center (CC)