Kees F, Färber L, Bucher M, Mair G, Mörike K, Grobecker H. Pharmacokinetics of therapeutic doses of tropisetron in healthy volunteers.
Br J Clin Pharmacol 2001;
52:705-7. [PMID:
11736884 PMCID:
PMC2014558 DOI:
10.1046/j.0306-5251.2001.01512.x]
[Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS
To establish the bioavailability of tropisetron (5 mg) administered orally as capsule compared with 2 mg given intravenously.
METHODS
Using a randomized crossover design, 18 healthy volunteers received a single oral dose of tropisetron (5 mg) and an intravenous bolus of tropisetron (2 mg) separated by a wash-out period of 1 week. Plasma concentrations of tropisetron were determined by h.p.l.c. and the pharmacokinetic parameters were estimated.
RESULTS
The mean pharmacokinetic parameters for 5 mg tropisetron given orally were Cmax 3.46 ng ml(-1), t(max) 2.6 h, t(1/2) 5.7 h and AUC(0,infinity) 32.9 ng ml(-1) h. After intravenous administration initial plasma concentration was 15.1 ng ml(-1), t(1/2) 5.6 h, AUC(0,infinity) 20.7 ng ml(-1) h, V 678 l and CL 1800 ml min(-1). An inverse correlation was demonstrated between CYP2D6 activity, measured by the sparteine metabolic ratio, and the bioavailability (mean 0.60, range 0.27-0.99) of oral tropisetron.
CONCLUSIONS
Tropisetron exhibits a wide range of oral bioavailability at therapeutic doses, which is mainly determined by CYP2D6 activity.
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