BACKGROUND: HIV protease inhibitors (HPIs) are an important component of highly active antiretroviral therapy. However, the activity of drug efflux transporters, such as P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRP1/MRP2), may limit intracellular drug accumulation. Drugs that inhibit the activity of drug efflux proteins may, in combination with HPIs, enhance the clinical efficacy of the drugs. METHODS: The transport of [(14)C]lopinavir was evaluated in peripheral blood mononuclear cells (PBMCs) in the absence or presence of known inhibitors: tariquidar (P-gp), MK571 (MRP), frusemide (MRP1/2), dipyridamole (MRP1/P-gp) and probenecid (MRP2/OATP). The effects of ritonavir, amprenavir and atazanavir on the accumulation of lopinavir were also evaluated in cultured CD4(+) T-lymphoblastoid cells [CEM (parental), CEM(VBL) (P-gp-overexpressing) and CEM(E1000) (MRP1-overexpressing)] and PBMCs. The relative expression of the drug efflux proteins on the PBMCs was assessed by flow cytometric and real-time PCR methods. RESULTS: Tariquidar, MK571, frusemide and dipyridamole all significantly increased the intracellular accumulation of lopinavir in the PBMCs, whereas probenecid decreased it. The cellular accumulation ratio (CAR) of lopinavir was also increased by ritonavir, amprenavir and atazanavir in a concentration-dependent manner in both cell types. The expression of P-gp, MRP1 and MRP2 mRNA were variable and individually did not correlate with CARs of lopinavir. CONCLUSIONS: We provide evidence that lopinavir is a substrate of P-gp, MRP1 and MRP2. The intracellular concentration of lopinavir is increased when co-incubated with ritonavir, amprenavir and atazanavir in PBMCs. Manipulation of drug efflux transporters may be a useful strategy for increasing the intracellular concentration and thereby enhancing the clinical efficacy of lopinavir.
BACKGROUND: HIV protease inhibitors (HPIs) are an important component of highly active antiretroviral therapy. However, the activity of drug efflux transporters, such as P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRP1/MRP2), may limit intracellular drug accumulation. Drugs that inhibit the activity of drug efflux proteins may, in combination with HPIs, enhance the clinical efficacy of the drugs. METHODS: The transport of [(14)C]lopinavir was evaluated in peripheral blood mononuclear cells (PBMCs) in the absence or presence of known inhibitors: tariquidar (P-gp), MK571 (MRP), frusemide (MRP1/2), dipyridamole (MRP1/P-gp) and probenecid (MRP2/OATP). The effects of ritonavir, amprenavir and atazanavir on the accumulation of lopinavir were also evaluated in cultured CD4(+) T-lymphoblastoid cells [CEM (parental), CEM(VBL) (P-gp-overexpressing) and CEM(E1000) (MRP1-overexpressing)] and PBMCs. The relative expression of the drug efflux proteins on the PBMCs was assessed by flow cytometric and real-time PCR methods. RESULTS:Tariquidar, MK571, frusemide and dipyridamole all significantly increased the intracellular accumulation of lopinavir in the PBMCs, whereas probenecid decreased it. The cellular accumulation ratio (CAR) of lopinavir was also increased by ritonavir, amprenavir and atazanavir in a concentration-dependent manner in both cell types. The expression of P-gp, MRP1 and MRP2 mRNA were variable and individually did not correlate with CARs of lopinavir. CONCLUSIONS: We provide evidence that lopinavir is a substrate of P-gp, MRP1 and MRP2. The intracellular concentration of lopinavir is increased when co-incubated with ritonavir, amprenavir and atazanavir in PBMCs. Manipulation of drug efflux transporters may be a useful strategy for increasing the intracellular concentration and thereby enhancing the clinical efficacy of lopinavir.
Authors: Soichi Haraguchi; Sarah K Ho; Matthew Morrow; Maureen M Goodenow; John W Sleasman Journal: J Leukoc Biol Date: 2011-04-19 Impact factor: 4.962
Authors: Daniel H Johnson; Charles Venuto; Marylyn D Ritchie; Gene D Morse; Eric S Daar; Paul J McLaren; David W Haas Journal: Pharmacogenet Genomics Date: 2014-04 Impact factor: 2.089
Authors: José Moltó; George Xinarianos; Cristina Miranda; Sudeep Pushpakom; Samandhy Cedeño; Bonaventura Clotet; Andrew Owen; Marta Valle Journal: Clin Pharmacokinet Date: 2013-07 Impact factor: 6.447
Authors: Antonio Valentin; Matthew Morrow; Richard H Poirier; Karen Aleman; Richard Little; Robert Yarchoan; George N Pavlakis Journal: AIDS Res Hum Retroviruses Date: 2010-01 Impact factor: 2.205