Intracellular Concentrations of Non-Nucleoside Reverse Transcriptase Inhibitors and its Potential Role on Apoptosis in Peripheral Blood Mononuclear Cells

2011 ◽  
Vol 03 (02) ◽  
Author(s):  
Akihiko Saitoh
2021 ◽  
Vol 12 ◽  
Author(s):  
Amedeo De Nicolò ◽  
Michele Pinon ◽  
Alice Palermiti ◽  
Antonello Nonnato ◽  
Alessandra Manca ◽  
...  

Tacrolimus (TAC) is a first-choice immunosuppressant for solid organ transplantation, characterized by high potential for drug-drug interactions, significant inter- and intra-patient variability, and narrow therapeutic index. Therapeutic drug monitoring (TDM) of TAC concentrations in whole blood (WB) is capable of reducing the incidence of adverse events. Since TAC acts within lymphocytes, its monitoring in peripheral blood mononuclear cells (PBMC) may represent a valid future alternative for TDM. Nevertheless, TAC intracellular concentrations and their variability are poorly described, particularly in the pediatric context. Therefore, our aim was describing TAC concentrations in WB and PBMC and their variability in a cohort of pediatric patients undergoing constant immunosuppressive maintenance therapy, after liver transplantation. TAC intra-PBMCs quantification was performed through a validated UHPLC–MS/MS assay over a period of 2–3 months. There were 27 patients included in this study. No significant TAC changes in intracellular concentrations were observed (p = 0.710), with a median percent change of −0.1% (IQR −22.4%–+46.9%) between timings: this intra-individual variability was similar to the one in WB, −2.9% (IQR −29.4–+42.1; p = 0.902). Among different patients, TAC weight-adjusted dose and age appeared to be significant predictors of TAC concentrations in WB and PBMC. Intra-individual seasonal variation of TAC concentrations in WB, but not in PBMC, have been observed. These data show that the intra-individual variability in TAC intracellular exposure is comparable to the one observed in WB. This opens the way for further studies aiming at the identification of therapeutic ranges for TAC intra-PBMC concentrations.


2007 ◽  
Vol 51 (8) ◽  
pp. 2943-2947 ◽  
Author(s):  
T. Holdich ◽  
L. A. Shiveley ◽  
J. Sawyer

ABSTRACT Apricitabine is a novel deoxycytidine analog reverse transcriptase inhibitor. In vitro apricitabine competes with other deoxycytidine analogues for intracellular phosphorylation mediated by deoxycytidine kinase. The topic of this study, the effect of concomitant administration of apricitabine and lamivudine on the plasma and intracellular pharmacokinetics of the two compounds, was investigated in healthy volunteers. Participants (n = 21; age, 18 to 30 years) received apricitabine at 600 mg twice daily, lamivudine at 300 mg once daily, and the two treatments in combination for 4 days each in random order. Plasma, urine, and intracellular pharmacokinetics were assessed on day 4 of each treatment period. Apricitabine was rapidly absorbed after oral administration, with peak concentrations being attained after a mean of 1.76 h. Coadministration with lamivudine had no significant effect on the plasma and urine pharmacokinetics of apricitabine. However, the formation of apricitabine triphosphate in peripheral blood mononuclear cells was markedly reduced after the coadministration of apricitabine and lamivudine than after the administration of apricitabine alone: the area under the concentration-time curve from 0 to 12 h for apricitabine triphosphate during combination treatment was ca. 15% of that seen after the administration of apricitabine alone. In contrast, apricitabine had no effect on the plasma pharmacokinetics of lamivudine or on the formation of lamivudine triphosphate in peripheral blood mononuclear cells. These results are consistent with in vitro findings that lamivudine inhibits the intracellular phosphorylation of apricitabine. In conjunction with similar in vitro observations for emtricitabine and apricitabine, these results suggest that apricitabine should not be coadministered with other deoxycytidine analogues for the treatment of human immunodeficiency virus infection.


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