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herbal product among HIV-infected patients because of its positive effects on cognitive function. Raltegravir, an HIV
integrase inhibitor, is increasingly being used as part of combined antiretroviral therapy. Clinical data on the potential
inhibitory or inductive effect of ginkgo biloba on the pharmacokinetics of raltegravir were lacking, and concomitant use
was not recommended. We studied the effect of ginkgo biloba extract on the pharmacokinetics of raltegravir in an openlabel,
randomized, two-period, crossover phase I trial in 18 healthy volunteers. Subjects were randomly assigned to a regimen
of 120 mg of ginkgo biloba twice daily for 15 days plus a single dose of raltegravir (400 mg) on day 15, a washout period,
and 400 mg of raltegravir on day 36 or the test and reference treatments in reverse order. Pharmacokinetic sampling
of raltegravir was performed up to 12 h after intake on an empty stomach. All subjects (9 male) completed the trial, and no
serious adverse events were reported. Geometric mean ratios (90% confidence intervals) of the area under the plasma concentration-
time curve from dosing to infinity (AUC0-) and the maximum plasma concentration (Cmax) of raltegravir with
ginkgo biloba versus raltegravir alone were 1.21 (0.93 to 1.58) and 1.44 (1.03 to 2.02). Ginkgo biloba did not reduce raltegravir
exposure. The potential increase in the Cmax of raltegravir is probably of minor importance, given the large intersubject
variability of raltegravir pharmacokinetics and its reported safety profile.