Drug Interactions of Echinacea, Ginseng, and Ginkgo Biloba Taken With Lopinavir/Ritonavir in Healthy Volunteers

Study 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 retu

Primary Outcome

The outcome measurement for each study arm is the change in lopinavir area under the concentration versus time curve (AUC) after two weeks administration of an herbal preparation (Ginkgo Biloba, Echinacea purpurea, or Panax Ginseng).

Conditions Studied

Interventions

• DRUG Gingko Biloba
• DRUG Echinacea purpurea
• DRUG Panax ginseng

Study Locations (1)