Drug Metabolism and Pharmacokinetics, GlaxoSmithKline, Research Triangle Park, NC 27709, USA.
Drug Metab Dispos. 2013 Feb;41(2):353-61. doi: 10.1124/dmd.112.048918. Epub 2012 Nov 6.
Dolutegravir (DTG; S/GSK1349572) is a potent HIV-1 integrase inhibitor with a distinct resistance profile and a once-daily dose regimen that does not require pharmacokinetic boosting. This work investigated the in vitro drug transport and metabolism of DTG and assessed the potential for clinical drug-drug interactions. DTG is a substrate for the efflux transporters P-glycoprotein (Pgp) and human breast cancer resistance protein (BCRP). Its high intrinsic membrane permeability limits the impact these transporters have on DTG's intestinal absorption. UDP-glucuronosyltransferase (UGT) 1A1 is the main enzyme responsible for the metabolism of DTG in vivo, with cytochrome P450 (P450) 3A4 being a notable pathway and UGT1A3 and UGT1A9 being only minor pathways. DTG demonstrated little or no inhibition (IC(50) values > 30 μM) in vitro of the transporters Pgp, BCRP, multidrug resistance protein 2, organic anion transporting polypeptide 1B1/3, organic cation transporter (OCT) 1, or the drug metabolizing enzymes CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 3A4, UGT1A1, or 2B7. Further, DTG did not induce CYP1A2, 2B6, or 3A4 mRNA in vitro using human hepatocytes. DTG does inhibit the renal OCT2 (IC(50) = 1.9 μM) transporter, which provides a mechanistic basis for the mild increases in serum creatinine observed in clinical studies. These in vitro studies demonstrate a low propensity for DTG to be a perpetrator of clinical drug interactions and provide a basis for predicting when other drugs could result in a drug interaction with DTG.
多替拉韦(DTG;S/GSK1349572)是一种有效的 HIV-1 整合酶抑制剂,具有独特的耐药谱和每日一次的剂量方案,无需进行药代动力学增强。这项工作研究了 DTG 的体外药物转运和代谢,并评估了临床药物相互作用的潜力。DTG 是外排转运蛋白 P-糖蛋白(Pgp)和乳腺癌耐药蛋白(BCRP)的底物。其高固有膜通透性限制了这些转运蛋白对 DTG 肠道吸收的影响。UDP-葡萄糖醛酸转移酶(UGT)1A1 是体内负责 DTG 代谢的主要酶,细胞色素 P450(CYP)3A4 是一个显著的途径,UGT1A3 和 UGT1A9 则是次要途径。DTG 对转运蛋白 Pgp、BCRP、多药耐药蛋白 2、有机阴离子转运多肽 1B1/3、有机阳离子转运体(OCT)1 或药物代谢酶 CYP1A2、2A6、2B6、2C8、2C9、2C19、2D6、3A4、UGT1A1 或 2B7 的体外抑制作用很小或没有(IC50 值>30 μM)。此外,DTG 在用人原代肝细胞进行的体外试验中也没有诱导 CYP1A2、2B6 或 3A4mRNA 的表达。DTG 确实抑制了肾脏 OCT2(IC50=1.9 μM)转运体,这为临床研究中观察到的血清肌酐轻度升高提供了机制基础。这些体外研究表明 DTG 作为临床药物相互作用的肇事者的倾向较低,并为预测其他药物何时可能与 DTG 发生药物相互作用提供了依据。