Auto-Induction of Intestinal First-Pass Effect Related Time-Dependent Pharmacokinetics of Artemisinin Rather than Dihydroartemisinin.
J Pharm Sci 2020;
110:458-466. [PMID:
32976901 DOI:
10.1016/j.xphs.2020.09.023]
[Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 08/29/2020] [Accepted: 09/16/2020] [Indexed: 11/27/2022]
Abstract
Artemisinin (ART) drugs showed declining plasma concentrations after repeated oral dosing, known as time-dependent pharmacokinetics (PK). ART and dihydroartemisinin (DHA) were adopted as representatives to evaluate the roles of first-pass effects and systemic metabolism in time-dependent PK by comparison of oral versus intravenous administration and 1 dose versus 5 consecutive doses PK in rats and dogs, respectively. The hepatic extraction ratio (ERh) and the intestinal elimination changes were further investigated in rats to distinguish the roles of hepatic first-pass effect or intestinal first-pass effect. The induction capacities of ARTs to cytochrome P450 (CYP450) in rats and human cells were evaluated as well. For ART, only the oral groups showed time-dependent PK. A fairly high ERh that obtained for ART was not sensitive to multiple oral doses. An increased elimination and CYP450 expression have also been found in the intestine. For DHA, though a significant CYP450 induction was observed, neither time-dependent PK nor changes in the first-pass effects was found. In conclusion, time-dependent PK of ART was mainly caused by the increased intestinal first-pass effect rather than hepatic first-pass effect or systemic metabolism. DHA was not involved in auto-induction elimination, thus showing no time-dependent PK.
Collapse