Studies on interactions between functional foods or dietary supplements and medicines. IV. Effects of ginkgo biloba leaf extract on the pharmacokinetics and pharmacodynamics of nifedipine in healthy volunteers.
The effects of Ginkgo biloba leaf extract (GBE), a widely used herbal dietary supplement in Japan, on the pharmacokinetics and pharmacodynamics of nifedipine (NFP), a calcium-channel blocker, were studied using 8 healthy volunteers. Simultaneous oral ingestion of GBE (240 mg) did not significantly affect any of the mean pharmacokinetic parameters of either NFP or dehydronifedipine, a major metabolite of NFP, after oral administration of NFP (10 mg). However, the maximal plasma NFP concentrations in 2 subjects were approximately doubled by GBE, and they had severer and longer-lasting headaches with GBE than without GBE, with dizziness or hot flushes in combination with GBE. The mean heart rate after oral administration of NFP with GBE tended to be faster than that without GBE at every time point. Accordingly, it was concluded that GBE and NFP should not be simultaneously ingested as much as possible, and careful monitoring is needed when administering NFP concomitantly with GBE to humans.
Yoshioka
Mutsunobu
M
Department of Pharmacy, Takarazuka City Hospital, Kohama, Japan.
Ohnishi
Noriaki
N
Koishi
Tomokazu
T
Obata
Yukihisa
Y
Nakagawa
Masato
M
Matsumoto
Tsuyoshi
T
Tagagi
Kentaro
K
Takara
Koji
K
Ohkuni
Tsuyoshi
T
Yokoyama
Teruyoshi
T
Kuroda
Kazuo
K
D000284:Administration, Oral; D000328:Adult; D019587:Dietary Supplements; D018565:Food-Drug Interactions / Q000502:physiology*; D020441:Ginkgo biloba; D006801:Humans; D008297:Male; D008875:Middle Aged; D009543:Nifedipine / Q000008:administration & dosage / Q000378:metabolism*; D010936:Plant Extracts / Q000008:administration & dosage / Q000378:metabolism; D018515:Plant Leaves
D010936:Plant Extracts; D009543:Nifedipine