POSTER PRESENTATION ABSTRACTS
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Salons 10-12.
THURSDAY, 5:30-6:15 PM
Chiang HM, Yang SY, Hou YC.
Marked decrease of oral bioavailablity of cyclosporin
caused by coadministration of American ginseng in rats.
Jen-Teh Junior College of Medicine, Nursing and
Management c726915@ms29.hinet.net
PURPOSE: Cyclosporin, an important immunosuppressant
with narrow therapeutic index, is a substrate for CYP3A4 and P-glycoprotein
(Pgp). Many studies reported that herbal constituents modulate CYP3A4
and Pgp. American ginseng (roots of Panax quinquefolium; AG)
is popularly used as health food and herbal medicine worldwide. This
study attempted to investigate the effect of AG on the absorption and
disposition of cyclosporin in rats.
METHODS: Rats were orally and intravenously
administered with cyclosporin with and without AG decoction in crossover
designs. Blood samples were withdrawn via cardiopuncture and assayed
by FPIA method. The pharmacokinetic parameters were calculated using
noncompartment model.
RESULTS: Our result indicated that the coadministration
of AG significantly decreased the Cmax and AUC of cyclosporin by 55.2%
and 57.6%, respectively. In addition, when AG was given 1 h before cyclosporin,
the AUC of cyclosporin was significantly reduced by 34.0%. When cyclosporin
was given intravenously to rats, no conspicuous difference of pharmacokinetic
parameters of cyclosporin between two treatments was found.
CONCLUSIONS: It is clear that concurrent use
of AG decreased the bioavailability of cyclosporin even AG was given
1 h before cyclosporin. The interaction should occur at the absorption
phase. Patients taking cyclosporin should be discouraged from using
AG concomitantly.
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