Selective deuterium substitution as a means of ameliorating clinically relevant pharmacokinetic drug interactions is demonstrated in this study. Carbon-deuterium bonds are more stable than corresponding carbon-hydrogen bonds. Using a precision deuteration platform, the two hydrogen atoms at the methylenedioxy carbon of paroxetine were substituted with deuterium. The new chemical entity, CTP-347 \[(3 S ,4 R )-3-((2,2-dideuterobenzo[ d \]\[1,3\]dioxol-5-yloxy)methyl)-4-(4-fluorophenyl)piperidine], demonstrated similar selectivity for the serotonin receptor, as well as similar neurotransmitter uptake inhibition in an in vitro rat synaptosome model, as unmodified paroxetine. However, human liver microsomes cleared CTP-347 faster than paroxetine as a result of decreased inactivation of CYP2D6. In phase 1 studies, CTP-347 was metabolized more rapidly in humans and exhibited a lower pharmacokinetic accumulation index than paroxetine. These alterations in the metabolism profile resulted in significantly reduced drug-drug interactions between CTP-347 and two other CYP2D6-metabolized drugs: tamoxifen (in vitro) and dextromethorphan (in humans). Our results show that precision deuteration can improve the metabolism profiles of existing pharmacotherapies without affecting their intrinsic pharmacologies.
本研究展示了选择性
氘代替作为改善临床相关药物代谢动力学相互作用的一种手段。碳-
氘键比对应的碳-氢键更稳定。利用精确
氘代平台,
帕罗西汀的亚甲基二氧碳上的两个氢原子被
氘替代。新化合物CTP-347 \[(3 S ,4 R )-3-((2,2-二
氘苯并[ d \]1,3-二氧ol-5-yloxy)甲基)-
4-(4-氟苯基)哌啶\]展示了与未修饰的
帕罗西汀类似的对
血清素受体的选择性,以及在体外大鼠突触体模型中相似的神经递质摄取抑制。然而,人体肝微粒体对CTP-347的清除速度比
帕罗西汀更快,原因是对CYP2D6的失活减少。在一期临床研究中,CTP-347在人体内代谢更快,并表现出比
帕罗西汀更低的药代动力学蓄积指数。这些代谢特征的改变导致CTP-347与两种其他CYP2D6代谢药物(
他莫昔芬(体外)和
右美沙芬(人体))之间的药物-药物相互作用显著减少。我们的结果表明,精确
氘代可以改善现有药物疗法的代谢特征,而不影响其内在药理作用。