The drug transporter P-glycoprotein limits oral absorption and brain entry of HIV-1 protease inhibitors.
Kim, R B
Currently available HIV-1 protease inhibitors are potent agents in the therapy of HIV-1 infection. However, limited oral absorption and variable tissue distribution, both of which are largely unexplained, complicate their use. We tested the hypothesis that P-glycoprotein is an important transporter for these agents. We studied the vectorial transport characteristics of indinavir, nelfinavir, and saquinavir in vitro using the model P-glycoprotein expressing cell lines L-MDR1 and Caco-2 cells, and in vivo after intravenous and oral administration of these agents to mice with a disrupted mdr1a gene. All three compounds were found to be transported by P-glycoprotein in vitro. After oral administration, plasma concentrations were elevated 2-5-fold in mdr1a (-/-) mice and with intravenous administration, brain concentrations were elevated 7-36-fold. These data demonstrate that P-glycoprotein limits the oral bioavailability and penetration of these agents into the brain. This raises the possibility that higher HIV-1 protease inhibitor concentrations may be obtained by targeted pharmacologic inhibition of P-glycoprotein transport activity.
ACESSO AO ARTIGOhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=508566
- Full blockade of intestinal P-glycoprotein and extensive inhibition of blood-brain barrier P-glycoprotein by oral treatment of mice with PSC833.
- HIV-1 protease inhibitors and the MDR1 multidrug transporter.
- Overview of P-glycoprotein inhibitors: a rational outlook
- P-glycoprotein expression in oral lichen planus
- Association between the number of coadministered P-glycoprotein inhibitors and serum digoxin levels in patients on therapeutic drug monitoring