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Dumond JB, Rigdon J, Mollan K, Tierney C, Kashuba ADM, Aweeka F, Collier AC. Brief Report: Significant Decreases in Both Total and Unbound Lopinavir and Amprenavir Exposures During Coadministration: ACTG Protocol A5143/A5147s Results. J Acquir Immune Defic Syndr 2015; 70:510-4. [PMID: 26230332 PMCID: PMC4648657 DOI: 10.1097/qai.0000000000000777] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This secondary analysis explored changes in protein-unbound concentrations of lopinavir and amprenavir when coadministered in HIV-infected subjects. Total and unbound pharmacokinetic parameters were calculated and compared between subjects receiving each agent alone and coadministration. When coadministered, unbound and total concentrations decrease. Coadministration significantly increased lopinavir unbound clearance, while significant changes in fraction unbound (fu) were not detected. For amprenavir, significant increases in fu and unbound clearance occurred with coadministration. This demonstrates the complex nature of drug-drug interactions between highly protein-bound, CYP-metabolized drugs, and the need to measure unbound concentrations in disease states such as hepatitis C, where such agents are coadministered.
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Affiliation(s)
- Julie B Dumond
- *UNC Eshelman School of Pharmacy, Division of Pharmacotherapy and Experimental Therapeutics, University of North Carolina at Chapel Hill, Chapel Hill, NC; †Gillings School of Global Public Health, Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, NC; ‡School of Medicine, Department of Internal Medicine, Division of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, NC; §Center for AIDS Research, Lineberger Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC; ‖Center for Biostatistics in AIDS Research, The Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA; ¶UCSF School of Pharmacy, Department of Clinical Pharmacy, San Francisco, CA; and #University of Washington School of Medicine, Division of Allergy and Infectious Diseases, Seattle, WA
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Pham PA, Hendrix CW, Barditch-Crovo P, Parsons T, Khan W, Parish M, Radebaugh C, Carson KA, Pakes GE, Qaqish R, Flexner C. Amprenavir and Lopinavir Pharmacokinetics following Coadministration of Amprenavir or Fosamprenavir with Lopinavir/Ritonavir, with or without Efavirenz. Antivir Ther 2007. [DOI: 10.1177/135965350701200614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Amprenavir (APV), fosamprenavir (FPV), lopinavir (LPV), ritonavir (RTV) and efavirenz (EFV) are to varying degrees substrates, inducers and inhibitors of CYP3A4. Coadministration of these drugs might result in complex pharmacokinetic drug-drug interactions. Methods Two prospective, open-label, non-randomized studies evaluated APV and LPV steady-state pharmacokinetics in HIV-infected patients on APV 750 mg twice daily + LPV/RTV 533/133 mg twice daily with EFV ( n=7) or without EFV ( n=12) + background nucleosides (Study 1) and after switching FPV 1,400 mg twice daily for APV ( n=10) (Study 2). Results In Study 1 EFV and non-EFV groups did not differ in APV minimum plasma concentration (Cmin; 1.10 versus 1.06μg/ml, P=0.89), area under the concentration-time curve (AUC; 17.46 versus 24.34μg•h/ml, P=0.22) or maximum concentration (Cmax; 2.61 versus 4.33 μg/ml, P=0.08); for LPV there was no difference in Cmin (median: 3.66 versus 6.18μg/ml, P=0.20), AUC (81.84 versus 93.75 μg•h/ml, P=0.37) or Cmax (10.36 versus 10.93 μg/ml, P=0.61). In Study 2, after switching from APV to FPV, APV Cmin increased by 58% (0.83 versus 1.30 μg/ml, P=0.0001), AUC by 76% (19.41 versus 34.24 μg•h/ml, P=0.0001), and Cmax by 75% (3.50 versus 6.14, P=0.001). Compared with historical controls, LPV and RTV pharmacokinetics were not changed. All treatment regimens were well tolerated. Seven of eight completers (88%) maintained HIV-1 RNA <400 copies/ml 12 weeks after the switch (1 lost to follow up). Conclusions EFV did not appear to significantly alter APV and LPV pharmacokinetic parameters in HIV-infected patients taking APV 750 mg twice daily + LPV 533/133 mg twice daily. Switching FPV 1,400 mg twice daily for APV 750 mg twice daily resulted in an increase in APV Cmin, AUC, and Cmax without changing LPV or RTV pharmacokinetics or overall tolerability.
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Affiliation(s)
| | | | | | | | - Wasif Khan
- Johns Hopkins Hospital, Baltimore, MD, USA
| | | | | | | | - Gary E Pakes
- GlaxoSmithKline, Research Triangle Park, NC, USA
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