RT Journal Article SR Electronic T1 Ritonavir, Saquinavir, and Efavirenz, but Not Nevirapine, Inhibit Bile Acid Transport in Human and Rat Hepatocytes JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 1068 OP 1075 DO 10.1124/jpet.106.102657 VO 318 IS 3 A1 Mary Peace McRae A1 Carolina M. Lowe A1 Xianbin Tian A1 David L. Bourdet A1 Richard H. Ho A1 Brenda F. Leake A1 Richard B. Kim A1 Kim L. R. Brouwer A1 Angela D. M. Kashuba YR 2006 UL http://jpet.aspetjournals.org/content/318/3/1068.abstract AB Human immunodeficiency virus-infected patients on antiretroviral drug therapy frequently experience hepatotoxicity, the underlying mechanism of which is poorly understood. Hepatotoxicity from other compounds such as bosentan and troglitazone has been attributed, in part, to inhibition of hepatocyte bile acid excretion. This work tested the hypothesis that antiretroviral drugs modulate hepatic bile acid transport. Ritonavir (28 μM), saquinavir (15 μM), and efavirenz (32 μM) inhibited [3H]taurocholate transport in bile salt export pump expressing Sf9-derived membrane vesicles by 90, 71, and 33%, respectively. In sandwich-cultured human hepatocytes, the biliary excretion index (BEI) of [3H]taurocholate was maximally decreased 59% by ritonavir, 39% by saquinavir, and 20% by efavirenz. Likewise, in sandwich-cultured rat hepatocytes, the BEI of [3H]taurocholate was decreased 100% by ritonavir and 94% by saquinavir. Sodium-dependent and -independent initial uptake rates of [3H]taurocholate in suspended rat hepatocytes were significantly decreased by ritonavir, saquinavir, and efavirenz. [3H]Taurocholate transport by recombinant NTCP and Ntcp was inhibited by ritonavir (IC50 = 2.1 and 6.4 μM in human and rat, respectively), saquinavir (IC50 = 6.7 and 20 μM, respectively), and efavirenz (IC50 = 43 and 97 μM, respectively). Nevirapine (75 μM) had no effect on bile acid transport in any model system. In conclusion, ritonavir, saquinavir, and efavirenz, but not nevirapine, inhibited both the hepatic uptake and biliary excretion of taurocholate. The American Society for Pharmacology and Experimental Therapeutics