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Gong WT, Zhao XJ, Wang GM, Ma XL, Huang JA. Efficacy of Zidovudine-Amikacin Combination Therapy In Vitro and in a Rat Tissue Cage Infection Model against Amikacin-Resistant, Multidrug-Resistant Enterobacteriales. Microbiol Spectr 2023; 11:e0484322. [PMID: 36946744 PMCID: PMC10101109 DOI: 10.1128/spectrum.04843-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 03/02/2023] [Indexed: 03/23/2023] Open
Abstract
Multidrug-resistant (MDR) Enterobacteriales infections have become an urgent global threat to public health. The aim of this study was to evaluate the efficacy of zidovudine-amikacin combination therapy in vitro and in vivo. Molecular characteristics and antibiotic resistance profiles of 53 amikacin-resistant MDR, extensively drug-resistant (XDR), or pan-drug-resistant (PDR) clinical isolates were examined via PCR and susceptibility testing. Checkerboard assays were performed for these 53 isolates to assess in vitro synergistic effects of the zidovudine-amikacin combination, and static time-kill experiments were performed for four XDR or PDR Enterobacteriales isolates. A Galleria mellonella model and a rat tissue cage infection model were established to assess in vivo synergistic effects. The aac(6')-Ib gene was detected in 25 (47.2%) isolates, followed by armA in 5 (9.4%) isolates, rmtB in 27 (50.9%) isolates, and rmtC in 3 (5.8%) isolates. Checkerboard assays showed the synergy of this combination against 38 (71.7%) isolates. The time-kill assays further confirmed that zidovudine strongly synergized with amikacin against four XDR or PDR Enterobacteriales isolates. The Galleria mellonella model study showed that the survival benefit of zidovudine-amikacin combination therapy was significantly better than that of monotherapy for those four Enterobacteriales isolates. Furthermore, the rat tissue cage infection model study showed that zidovudine-amikacin combination therapy displayed more potent bactericidal activity than monotherapy after 3 and 7 days of treatment for the above four isolates. Our data support the idea that the zidovudine-amikacin combination could be a plausible alternative therapy against infections with amikacin-resistant MDR Enterobacteriales, especially with XDR and PDR Enterobacteriales. IMPORTANCE Our study revealed for the first time that the zidovudine-amikacin combination shows a significant bactericidal effect against amikacin-resistant MDR, XDR, and PDR Enterobacteriales. Second, using in vitro and in vivo approaches, our study showed that zidovudine strongly synergized with amikacin against amikacin-resistant MDR Enterobacteriales isolates. Most importantly, with regard to survival benefit, pharmacokinetics, and bactericidal effects, our in vivo experiment demonstrated the effectiveness of zidovudine-amikacin.
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Affiliation(s)
- Wei-Tao Gong
- Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
- Department of Pulmonary and Critical Care Medicine, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiao-Jie Zhao
- Department of Laboratory Medicine, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Gao-Ming Wang
- Department of Thoracic Surgery, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiao-Lin Ma
- Department of Neurology, Xuzhou Central Hospital, Xuzhou Clinical School of Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Jian-An Huang
- Department of Pulmonary and Critical Care Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, China
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Krakovka S, Ranjbarian F, Luján LA, Saura A, Larsen NB, Jiménez-González A, Reggenti A, Luján HD, Svärd SG, Hofer A. Giardia intestinalis thymidine kinase is a high-affinity enzyme crucial for DNA synthesis and an exploitable target for drug discovery. J Biol Chem 2022; 298:102028. [PMID: 35568200 PMCID: PMC9190010 DOI: 10.1016/j.jbc.2022.102028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 05/06/2022] [Accepted: 05/07/2022] [Indexed: 11/18/2022] Open
Abstract
Giardiasis is a diarrheal disease caused by the unicellular parasite Giardia intestinalis, for which metronidazole is the main treatment option. The parasite is dependent on exogenous deoxyribonucleosides for DNA replication and thus is also potentially vulnerable to deoxyribonucleoside analogs. Here, we characterized the G. intestinalis thymidine kinase, a divergent member of the thymidine kinase 1 family that consists of two weakly homologous parts within one polypeptide. We found that the recombinantly expressed enzyme is monomeric, with 100-fold higher catalytic efficiency for thymidine compared to its second-best substrate, deoxyuridine, and is furthermore subject to feedback inhibition by dTTP. This efficient substrate discrimination is in line with the lack of thymidylate synthase and dUTPase in the parasite, which makes deoxy-UMP a dead-end product that is potentially harmful if converted to deoxy-UTP. We also found that the antiretroviral drug azidothymidine (AZT) was an equally good substrate as thymidine and was active against WT as well as metronidazole-resistant G. intestinalis trophozoites. This drug inhibited DNA synthesis in the parasite and efficiently decreased cyst production in vitro, which suggests that it could reduce infectivity. AZT also showed a good effect in G. intestinalis–infected gerbils, reducing both the number of trophozoites in the small intestine and the number of viable cysts in the stool. Taken together, these results suggest that the absolute dependency of the parasite on thymidine kinase for its DNA synthesis can be exploited by AZT, which has promise as a future medication effective against metronidazole-refractory giardiasis.
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Affiliation(s)
- Sascha Krakovka
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden
| | - Farahnaz Ranjbarian
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Lucas A Luján
- Centro de Investigación y Desarrollo en Immunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Cordoba, Argentina
| | - Alicia Saura
- Centro de Investigación y Desarrollo en Immunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Cordoba, Argentina
| | | | | | - Anna Reggenti
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Hugo D Luján
- Centro de Investigación y Desarrollo en Immunología y Enfermedades Infecciosas (CIDIE), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)/Universidad Católica de Córdoba (UCC), Cordoba, Argentina
| | - Staffan G Svärd
- Department of Cell and Molecular Biology, BMC, Uppsala University, Uppsala, Sweden.
| | - Anders Hofer
- Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden.
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Zidovudine in synergistic combination with fosfomycin: an in vitro and in vivo evaluation against multidrug-resistant Enterobacterales. Int J Antimicrob Agents 2021; 58:106362. [PMID: 34010710 DOI: 10.1016/j.ijantimicag.2021.106362] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Revised: 04/29/2021] [Accepted: 05/08/2021] [Indexed: 12/20/2022]
Abstract
Multidrug-resistant (MDR) Enterobacterales are a priority health issue with few treatment options. Recently, fosfomycin has been reconsidered for MDR bacterial infections. Zidovudine, licensed for the treatment of human immunodeficiency virus (HIV), has unexploited antibacterial properties and has been considered for drug repurposing. The aim of this study was to assess the effect of the combination of fosfomycin plus zidovudine against clinical MDR Enterobacterales isolates. Minimum inhibitory concentration (MIC) determination and checkerboard assays for 36 MDR Enterobacterales strains were performed. In addition, fosfomycin-resistant strains were evaluated using time-kill assay and in an in vivo Galleria mellonella infection model. Zidovudine and fosfomycin MICs ranged between 0.06 to >64 mg/L and 0.125 to >512 mg/L, respectively. A synergistic effect [fractional inhibitory concentration index (FICI) ≤0.5] was observed in 25 isolates and no antagonistic effect was observed in the remaining isolates. For 7 of 8 fosfomycin-resistant strains (MIC > 32 mg/L), zidovudine combination was able to restore fosfomycin susceptibility. These results were confirmed by time-kill assays. Fosfomycin + zidovudine presented greater larval survival (20-50%) than monotherapy. Synergistic activity was observed for fosfomycin + zidovudine in 69.4% of the tested strains. In vivo experiments confirmed the enhanced effectiveness of the combination. The zidovudine concentrations tested here can be reached in human serum using the actual licensed dosage, therefore this combination deserves further clinical investigation.
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Combination of Colistin and Azidothymidine Demonstrates Synergistic Activity against Colistin-Resistant, Carbapenem-Resistant Klebsiella pneumoniae. Microorganisms 2020; 8:microorganisms8121964. [PMID: 33322306 PMCID: PMC7764370 DOI: 10.3390/microorganisms8121964] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/01/2020] [Accepted: 12/09/2020] [Indexed: 11/17/2022] Open
Abstract
Carbapenem-resistant Enterobacteriaceae (CRE) is listed as an urgent threat by the World Health Organization because of the limited therapeutic options, rapid evolution of resistance mechanisms, and worldwide dissemination. Colistin is a common backbone agent among the “last-resort” antibiotics for CRE; however, its emerging resistance among CRE has taken the present dilemma to the next level. Azidothymidine (AZT), a thymidine analog used to treat human immunodeficiency virus/acquired immunodeficiency syndrome, has been known to possess antibacterial effects against Enterobacteriaceae. In this study, we investigated the combined effects of AZT and colistin in 40 clinical isolates of colistin-resistant, carbapenem-resistant K. pneumoniae (CCRKP). Eleven of the 40 isolates harbored Klebsiella pneumoniae carbapenemase. The in vitro checkerboard method and in vivo nematode killing assay both revealed synergistic activity between the two agents, with fractional inhibitory concentration indexes of ≤0.5 in every strain. Additionally, a significantly lower hazard ratio was observed for the nematodes treated with combination therapy (0.288; p < 0.0001) compared with either AZT or colistin treatment. Toxicity testing indicated potentially low toxicity of the combination therapy. Thus, the AZT–colistin combination could be a potentially favorable therapeutic option for treating CCRKP.
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Peyclit L, Baron SA, Yousfi H, Rolain JM. Zidovudine: A salvage therapy for mcr-1 plasmid-mediated colistin-resistant bacterial infections? Int J Antimicrob Agents 2018; 52:11-13. [DOI: 10.1016/j.ijantimicag.2018.03.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 12/18/2022]
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Cressey TR, Punyawudho B, Le Coeur S, Jourdain G, Saenjum C, Capparelli E, Jittayanun K, Phanomcheong S, Luvira A, Borkird T, Puangsombat A, Aarons L, Sukrakanchana PO, Urien S, Lallemant M. Assessment of Nevirapine Prophylactic and Therapeutic Dosing Regimens for Neonates. J Acquir Immune Defic Syndr 2017; 75:554-560. [PMID: 28489732 PMCID: PMC5508655 DOI: 10.1097/qai.0000000000001447] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Nevirapine (NVP) is a key component of antiretroviral prophylaxis and treatment for neonates. We evaluated current World Health Organization (WHO) weight-band NVP prophylactic dosing recommendations and investigated optimal therapeutic NVP dosing for neonates. METHODS The PHPT-5 study in Thailand assessed the efficacy of "Perinatal Antiretroviral Intensification" to prevent mother-to-child transmission of HIV in women with <8 weeks of antiretroviral treatment before delivery (NCT01511237). Infants received a 2-week course of zidovudine/lamivudine/NVP (NVP syrup/once daily: 2 mg/kg for 7 days; then 4 mg/kg for 7 days). Infant samples were assessed during the first 2 weeks of life. NVP population pharmacokinetics (PK) parameters were estimated using nonlinear mixed-effects models. Simulations were performed to estimate the probability of achieving target NVP trough concentrations for prophylaxis (>0.10 mg/L) and for therapeutic efficacy (>3.0 mg/L) using different infant dosing strategies. RESULTS Sixty infants (55% male) were included. At birth, median (range) weight was 2.9 (2.3-3.6) kg. NVP concentrations were best described by a 1-compartment PK model. Infant weight and postnatal age influenced NVP PK parameters. Based on simulations for a 3-kg infant, ≥92% would have an NVP trough >0.1 mg/L after 48 hours through 2 weeks using the PHPT-5 and WHO-dosing regimens. For NVP-based therapy, a 6-mg/kg twice daily dose produced a trough >3.0 mg/L in 87% of infants at 48 hours and 80% at 2 weeks. CONCLUSION WHO weight-band prophylactic guidelines achieved target concentrations. Starting NVP 6 mg/kg twice daily from birth is expected to achieve therapeutic concentrations during the first 2 weeks of life.
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Affiliation(s)
- Tim R. Cressey
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Department of Molecular & Clinical Pharmacology, University of Liverpool, UK
| | - Baralee Punyawudho
- Department of Pharmaceutical Care, Faculty of Pharmacy, Chiang Mai University, Chiang Mai, Thailand
| | - Sophie Le Coeur
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut d’Etudes Démographiques, Paris, France
| | - Gonzague Jourdain
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut de Recherche pour le Développement (IRD) UMI 174-PHPT, Marseille, France
| | - Chalermpong Saenjum
- Department of Pharmaceutical Sciences, Faculty of Pharmacy, Chiang Mai University, Thailand
| | | | - Kanokwan Jittayanun
- Pediatric Department, Health Promotion Center Region 10, Chiang Mai, Thailand
| | | | - Anita Luvira
- Pediatric Department, Nopparat Rajathanee Hospital
| | | | | | - Leon Aarons
- Manchester Pharmacy School, The University of Manchester, Manchester, UK
| | | | - Saik Urien
- EAU7323 Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Marc Lallemant
- PHPT/IRD 174, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
- Department of Immunology & Infectious Diseases, Boston, Harvard T.H Chan School of Public Health, MA, USA
- Institut de Recherche pour le Développement (IRD) UMI 174-PHPT, Marseille, France
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Bushman LR, Kiser JJ, Rower JE, Klein B, Zheng JH, Ray ML, Anderson PL. Determination of nucleoside analog mono-, di-, and tri-phosphates in cellular matrix by solid phase extraction and ultra-sensitive LC-MS/MS detection. J Pharm Biomed Anal 2011; 56:390-401. [PMID: 21715120 DOI: 10.1016/j.jpba.2011.05.039] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2010] [Revised: 05/19/2011] [Accepted: 05/27/2011] [Indexed: 12/17/2022]
Abstract
An ultra-sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay was developed and validated to facilitate the assessment of clinical pharmacokinetics of nucleotide analogs from lysed intracellular matrix. The method utilized a strong anion exchange isolation of mono-(MP), di-(DP), and tri-phosphates (TP) from intracellular matrix. Each fraction was then dephosphorylated to the parent moiety yielding a molar equivalent to the original nucleotide analog intracellular concentration. The analytical portion of the methodology was optimized in specific nucleoside analog centric modes (i.e. tenofovir (TFV) centric, zidovudine (ZDV) centric), which included desalting/concentration by solid phase extraction and detection by LC-MS/MS. Nucleotide analog MP-, DP-, and TP-determined on the TFV centric mode of analysis include TFV, lamivudine (3TC), and emtricitibine (FTC). The quantifiable linear range for TFV was 2.5-2000 fmol/sample, and that for 3TC/FTC was 0.1 200 pmol/sample. Nucleoside analog MP-, DP-, and TP-determined on the ZDV centric mode of analysis included 3TC and ZDV. The quantifiable linear range for 3TC was 0.1 100 pmol/sample, and 5-2000 fmol/sample for ZDV. Stable labeled isotopic internal standards facilitated accuracy and precision in alternative cell matrices, which supported the intended use of the method for MP, DP, and TP determinations in various cell types. The method was successfully applied to clinical research samples generating novel intracellular information for TFV, FTC, ZDV, and 3TC nucleotides. This document outlines method development, validation, and application to clinical research.
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Affiliation(s)
- Lane R Bushman
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Mail Stop V20-C238, 12850 E. Montview Blvd., Aurora, Colorado 80045, USA
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Abstract
Drug development involves learning and confirming in healthy volunteers and ultimately in patients. This approach should apply to drug-drug interactions because requirements to extrapolate pharmacokinetic and pharmacodynamic findings from healthy volunteers to patients are not uniformly met, and the designs of interaction studies often have little relevance to actual clinical use. Guidance to health-care professionals on a safe and effective dose for individual patients should include information from drug-drug interaction studies in the intended patients.
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Ramautarsing R, Ananworanich J. Generic and low dose antiretroviral therapy in adults and children: implication for scaling up treatment in resource limited settings. AIDS Res Ther 2010; 7:18. [PMID: 20569473 PMCID: PMC2898660 DOI: 10.1186/1742-6405-7-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 06/23/2010] [Indexed: 11/10/2022] Open
Abstract
Although access to antiretroviral therapy (ART) for the treatment of HIV has increased during the last decade, many patients are still in need of treatment. With limited funds to provide ART to millions of patients worldwide, there is a need for alternative ways to scale up ART in resource limited settings. This review provides an overview of pharmacokinetic, safety and efficacy studies of generic and reduced dose ART. The production of generic ART has greatly influenced the decline in drug prices and the increased in ART access. Generic ART has good pharmacokinetic profile, safety and efficacy. Toxicity is however the main cause for ART discontinuation. Several dose reduction studies have shown adequate pharmacokinetic parameters and short term efficacy with reduced dose ART. Ethnicity may affect drug metabolism; several pharmacokinetic studies have confirmed higher plasma ART concentration in Asians. Randomized efficacy trial of reduced versus standard ART is warranted.
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Affiliation(s)
- Reshmie Ramautarsing
- The HIV Netherlands Australia Thailand Research Collaboration (HIVNAT), Bangkok, Thailand
- Centre for Poverty-related Communicable Diseases (CPCD), Department of Internal Medicine, Academic Medical Centre, University of Amsterdam, Amsterdam, the Netherlands
| | - Jintanat Ananworanich
- The HIV Netherlands Australia Thailand Research Collaboration (HIVNAT), Bangkok, Thailand
- The Southeast Asia Research Collaboration with Hawaii (SEARCH), Bangkok, Thailand
- Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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Abstract
PURPOSE OF REVIEW This review summarizes recent developments regarding the unique clinical pharmacologic profile of nucleoside analog reverse transcriptase inhibitors for management of HIV. RECENT FINDINGS First, intracellular data in patients suggest that nucleoside reverse transcriptase inhibitor-triphosphates are compartmentalized in different cell types. Additionally, intracellular drug-drug interactions were identified, which were undetectable in plasma. Second, extracellular data illustrate multiple bidirectional plasma drug-drug interactions between renally eliminated tenofovir and liver-metabolized drugs. Definitive mechanistic details for these interactions are lacking but they appear to involve renal and/or enteric drug transporters. Furthermore, the plasma versus female genital tract disposition of these agents was recently elucidated, which is important for currently investigated indications for pre-exposure and post-exposure prophylaxis. Finally, tenofovir/emtricitabine and abacavir (using a promising human leukocyte antigen-B*5701 genetic test for hypersensitivity)/lamivudine have emerged as common first-line nucleoside analog reverse transcriptase inhibitors because of co-formulations, once-daily dosing, and favorable tolerability and adverse effect profiles. Nevertheless, elucidating the long-term safety profile for all nucleoside analog reverse transcriptase inhibitors remains a priority. SUMMARY Knowledge of nucleoside analog reverse transcriptase inhibitor disposition intracellularly and extracellularly has expanded. This provides a basis for rational use of these agents clinically and adds new perspectives for future research.
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Pharmacokinetic-pharmacodynamic relationship of NRTIs and its connection to viral escape: an example based on zidovudine. Eur J Pharm Sci 2008; 36:532-43. [PMID: 19150497 DOI: 10.1016/j.ejps.2008.12.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 11/26/2008] [Accepted: 12/08/2008] [Indexed: 11/20/2022]
Abstract
In HIV disease, the mechanisms of drug resistance are only poorly understood. Incomplete suppression of HIV by antiretroviral agents is suspected to be a main reason. The objective of this in silico study is to elucidate the pharmacokinetic origins of incomplete viral suppression, exemplified for zidovudine (AZT) as a representative of the key class of nucleoside reverse transcriptase inhibitors (NRTIs). AZT, like other NRTIs, exerts its main action through its intra-cellular triphoshate (AZT-TP) by competition with natural thymidine triphosphate. We developed a physiologically based pharmacokinetic (PBPK) model describing the intra-cellular pharmacokinetics of AZT anabolites and subsequently established the pharmacokinetic-pharmacodynamic relationship. The PBPK model has been validated against clinical data of different dosing schemes. We reduced the PBPK model to derive a simple three-compartment model for AZT and AZT-TP that can readily be used in population analysis of clinical trials. A novel machanistic, and for NRTIs generic effect model has been developed that incorporates the primary effect of AZT-TP and potential secondary effect of zidovudine monophosphate. The proposed models were used to analyze the efficacy and potential toxicity of different dosing schemes for AZT. Based on the mechanism of action of NRTIs, we found that drug heterogeneities due to temporal fluctuations can create a major window of unsuppressed viral replication. For AZT, this window was most pronounced for a 600 mg/once daily dosing scheme, in which insufficient viral suppression was observed for almost half the dosing period.
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Anderson PL, King T, Zheng JH, MaWhinney S. Cytokine and sex hormone effects on zidovudine- and lamivudine-triphosphate concentrations in vitro. J Antimicrob Chemother 2008; 62:738-45. [PMID: 18567572 DOI: 10.1093/jac/dkn247] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
INTRODUCTION Elevated zidovudine- and lamivudine-triphosphates have been observed in peripheral blood mononuclear cells (PBMCs) from females versus males and in patients with high inflammatory states versus lower inflammatory states. Consistent with high triphosphate exposures, these same patient groups also experience elevated rates of toxicity, including lipoatrophy. The purpose of this study was to evaluate the effects of oestradiol, progesterone and testosterone as well as tumour necrosis factor (TNF)-alpha and interferon (IFN)-alpha on zidovudine- and lamivudine-triphosphates in PBMCs and, for the cytokines, in 3T3-L1 adipocytes. METHODS Multiple replicates of adipocytes and human PBMCs were incubated with experimental versus control conditions using several cytokine and sex hormone doses. Zidovudine- and lamivudine-triphosphate concentrations were determined with validated LC-MS-MS assays. A mixed effects, cell means model that accounted for experiment number was used to evaluate the effects of experimental conditions relative to control. RESULTS In adipocytes, TNF-alpha doses below 2 ng/mL increased zidovudine-triphosphate by 18% (5-31%). Lamivudine-triphosphate was not detectable in adipocytes. In PBMCs, pooled IFN-alpha doses (0.1-10 U/mL) decreased zidovudine-triphosphate 26% (10-42%); 100 and 1000 ng/mL of progesterone decreased lamivudine-triphosphate by 22% (1-43%) and 47% (25-68%), respectively. Pooled testosterone doses (10-1000 ng/mL) decreased lamivudine-triphosphate by 24% (7-41%). No other statistically significant effects were observed. CONCLUSIONS We found evidence that sex hormones and cytokines influence zidovudine-triphosphate and lamivudine-triphosphate slightly in PBMCs and adipocytes in vitro. These findings provide insight and scientific direction to address inflammation-dependent and sex-dependent phosphorylation and responses in patients.
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Affiliation(s)
- Peter L Anderson
- Department of Pharmaceutical Sciences, University of Colorado Denver, Denver, CO 80262, USA.
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High levels of zidovudine (AZT) and its intracellular phosphate metabolites in AZT- and AZT-lamivudine-treated newborns of human immunodeficiency virus-infected mothers. Antimicrob Agents Chemother 2008; 52:2555-63. [PMID: 18426897 DOI: 10.1128/aac.01130-07] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Newborns from human immunodeficiency virus-infected mothers are given antiretroviral prophylaxis against mother-to-child transmission, including predominantly nucleoside reverse transcriptase inhibitors. Pharmacological monitoring of these drugs in newborns has so far been limited to plasma and cord blood. In this study, samples from newborns (up to 45 days old) treated with zidovudine (AZT) alone (n = 29) or in combination with lamivudine (3TC) (n = 20) were analyzed for both intracellular concentrations of phosphate metabolites in peripheral blood mononuclear cells and levels of parent drugs in plasma. Plasma AZT and intracellular AZT-monophosphate and AZT-triphosphate (TP) concentrations were significantly higher during the first 15 days of life (199 versus 52.7 ng/ml [P < 0.0001], 732 versus 282 fmol/10(6) cells [P < 0.0001], and 170 versus 65.1 fmol/10(6) cells [P < 0.0001], respectively) and then became comparable to those of adults. No difference in intracellular AZT metabolite concentrations was found when AZT- and AZT-3TC-treated groups were compared. Plasma 3TC levels (lower limit of quantification [LLOQ], 1,157 ng/ml; median, 412.5 ng/ml) were not associated with the newborn's age, gender, or weight. Intracellular 3TC-TP concentrations (LLOQ, 40.4 pmol/10(6) cells; median, 18.9 pmol/10(6) cells) determined for newborns receiving the AZT-3TC combination were associated with neither the age nor weight of the newborns. Concentrations in females were significantly higher (1.8-fold [P = 0.0415]) than those in males. Unexpectedly, newborns on AZT monotherapy whose mothers' treatment included 3TC displayed residual plasma 3TC and intracellular 3TC-TP levels up to 1 week after birth.
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Anderson PL, Zheng JH, King T, Bushman LR, Predhomme J, Meditz A, Gerber J, Fletcher CV. Concentrations of zidovudine- and lamivudine-triphosphate according to cell type in HIV-seronegative adults. AIDS 2007; 21:1849-54. [PMID: 17721092 DOI: 10.1097/qad.0b013e3282741feb] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Concentrations of zidovudine (ZDV)- and lamivudine (3TC)-triphosphates (TP) have been quantified in unfractionated peripheral blood mononuclear cells (PBMC) from HIV+ patients. The objective of this study was to determine whether concentrations of ZDV-TP and 3TC-TP in PBMC reflect the concentrations within CD4 T cells in HIV-seronegative adults. METHODS Volunteers had taken 300 mg of ZDV plus 150 mg of 3TC twice daily for > or = 7 days. Blood (60 mL) was collected 2 or 5 h post observed dose. PBMC were processed into three cell fractions using CD4 magnetic immunobeads: CD4-purified cells; unfractionated PBMC; and CD4-depleted PBMC. TP were determined in each cell fraction with liquid chromatography-mass spectrometry and compared across cell types by non-parametric analyses. RESULTS Six males and two females participated. The median (range) percentage of CD4 T cells (CD4%) in each fraction were: CD4-purified, 99%; unfractionated, 63% (range, 53-70); and CD4-depleted, 14% (range, 4-29). Corresponding median (range) ZDV-TP concentrations were 8.0 (5.3-10.3), 26.5 (12.9-42.2), and 34.2 (16.4-52.2) fmol/1 x 10 cells (Friedman P = 0.0008). The 3TC-TP values were 4.6 (2.3-6.7), 4.8 (3.5-8.8), and 6.8 (4.0-13.1) pmol//1 x 10 cells (Friedman P = 0.01). In mixed model analyses: ZDV-TP (fmol/1 x 10 cells) = 42-0.32 (CD4%); P < 0.001 and 3TC-TP (pmol/1 x 10 cells) = 7.3-0.03(CD4%); P = 0.003. CONCLUSIONS In HIV-seronegative volunteers, 3TC-TP concentrations in PBMC reflected the concentrations within CD4 T cells, but ZDV-TP concentrations were more than 70% lower in CD4 T cells than in PBMC. Thus, TP concentrations differ according to cell type in vivo with corresponding efficacy and toxicity implications for cells with low or high triphosphates.
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Affiliation(s)
- Peter L Anderson
- University of Colorado Health Sciences Center, Denver, Colorado 80262, USA.
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Robbins BL, Poston PA, Neal EF, Slaughter C, Rodman JH. Simultaneous measurement of intracellular triphosphate metabolites of zidovudine, lamivudine and abacavir (carbovir) in human peripheral blood mononuclear cells by combined anion exchange solid phase extraction and LC-MS/MS. J Chromatogr B Analyt Technol Biomed Life Sci 2006; 850:310-7. [PMID: 17197254 DOI: 10.1016/j.jchromb.2006.12.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 11/30/2006] [Accepted: 12/01/2006] [Indexed: 10/23/2022]
Abstract
All nucleoside reverse transcriptase inhibitors (NRTI) must first be metabolized to their triphosphate forms in order to be active against HIV. Zidovudine (ZDV), abacavir (ABC) and lamivudine (3TC) have proven to be an efficacious combination. In order simultaneously to measure intracellular levels of the triphosphates (-TP) of ZDV, ABC (carbovir, CBV) and 3TC, either together or individually, we have developed a cartridge-LC-MS/MS method. The quantitation range was 2.5-250 pg/microl for 3TC-TP, 0.1-10.0 pg/microl for ZDV-TP and 0.05-5.00 pg/microl for CBV-TP. This corresponds to 0.1-11.0 pmol 3TC-TP per million cells, 4-375 fmol ZDV-TP per million cells and 2-200 fmol CBV-TP per million cells, extracted from 10 million cells. Patient samples demonstrated measured levels in the middle regions of our standard curves both at pre-dose and 4h post-dose times.
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Affiliation(s)
- Brian L Robbins
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN, USA.
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Cressey TR, Leenasirimakul P, Jourdain G, Tawon Y, Sukrakanchana PO, Lallemant M. Intensive Pharmacokinetics of Zidovudine 200 mg Twice Daily in HIV-1-Infected Patients Weighing Less Than 60 kg on Highly Active Antiretroviral Therapy. J Acquir Immune Defic Syndr 2006; 42:387-9. [PMID: 16810125 DOI: 10.1097/01.qai.0000221685.90681.1b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Turriziani O, Butera O, Gianotti N, Parisi SG, Mazzi R, Girardi E, Iaiani G, Antonelli L, Lazzarin A, Antonelli G. Thymidine kinase and deoxycytidine kinase activity in mononuclear cells from antiretroviral-naive HIV-infected patients. AIDS 2005; 19:473-9. [PMID: 15764852 DOI: 10.1097/01.aids.0000162335.12815.12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To evaluate whether an inter-individual variability in the activity of thymidine kinase (TK) and deoxycytidine kinase (dCK), which are involved in the first step of phosphorylation of some nucleoside analogues, exists in antiretroviral-naive, HIV-seropositive patients. DESIGN Forty-five randomly selected antiretroviral-naive HIV-infected patients were recruited, together with 26 healthy volunteers with no concurrent infection and under no pharmacological treatment. METHODS Peripheral blood mononuclear cells (PBMC) were isolated from venous blood and their TK and dCK activities evaluated. CD4 T cells and HIV-RNA were measured in HIV-infected patients, too. RESULTS There was a broad range of variability in TK activity in HIV-infected individuals. Furthermore, the activity in PBMC was significantly higher in HIV-infected individuals than in healthy volunteers. dCK activity in seropositive patients was significantly lower than in healthy volunteers. A marked inter-individual variability in dCK levels was observed in the HIV-infected group. No correlations were found between TK or dCK activities and plasma viral load, CD4 cell count, sex or age of patients. CONCLUSIONS A marked range of inter-individual variability of TK and dCK activities in PBMC exists in HIV-infected individuals but not in healthy volunteers, indicating that the activity of enzymes with key roles in drug activation could vary greatly from one patient to another. Furthermore, TK expression is greater in HIV-infected individuals than in healthy volunteers. Better understanding of the viral or cellular factors that contribute to this variability, as well as their effect on responses to antiretroviral treatment, may aid optimization of the management of HIV-infected patients.
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Affiliation(s)
- Ombretta Turriziani
- Department of Experimental Medicine and Pathology, Virology Section, University La Sapienza, 28 00185 Rome, Italy
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Becher F, Landman R, Mboup S, Kane CNT, Canestri A, Liegeois F, Vray M, Prevot MH, Leleu G, Benech H. Monitoring of didanosine and stavudine intracellular trisphosphorylated anabolite concentrations in HIV-infected patients. AIDS 2004; 18:181-7. [PMID: 15075534 DOI: 10.1097/00002030-200401230-00006] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVE To determine the concentrations of intracellular active anabolites of stavudine (d4T) and didanosine (DDI) and their interpatient variability in HIV-infected patients and to explore relationships between plasma and intracellular forms. METHODS This pilot study included 28 antiretroviral-naive HIV-infected patients who received d4T (40/30 mg twice daily), ddI (400/250 mg daily) and efavirenz (600 mg daily). After 6 months of therapy, 7 ml of blood was collected between 0.5 and 16.2 h and 2.5 and 28.5 h after the last dose of d4T and ddI, respectively. Plasma samples were obtained for the determination of d4T and ddI concentrations. Peripheral blood mononuclear cells were prepared for measuring intracellular d4T and ddI triphosphates (d4T-TP and ddA-TP, respectively). RESULTS d4T-TP and ddA-TP concentrations were above the limit of quantification in 25 of 26 compliant patients: median d4T-TP was 31 fmol/10(6) cells (range, 0-99) and median ddA-TP was 8 fmol/10(6) cells (range, 0-23). The half-life of d4T-TP was calculated as 7 h. Interpatient variability in d4T-TP and ddA-TP concentrations was 48% and 58%, respectively. A significant relationship was observed between plasma d4T and intracellular d4T-TP. No relation was found between ddI and ddA-TP. A linear relation was observed between the intracellular concentrations of d4T-TP and ddA-TP. CONCLUSION This is the first time that data have been obtained on intracellular concentrations of d4T-TP and ddA-TP, their intracellular pharmacokinetics and interpatient variability. Other similar studies with more patients are needed to enhance knowledge of the intracellular pharmacology of the nucleoside reverse transcriptase inhibitors.
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Affiliation(s)
- François Becher
- CEA, Pharmacology and Immunology Unit, DSV/DRM, Gif-Sur-Yvette, France
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Abstract
Antiretroviral treatment of HIV-infected pregnant women is widely used to prevent mother-to-child HIV transmission and as primary therapy of maternal HIV infection. The physiological changes associated with pregnancy have a large impact on drug disposition, and changes in antiretroviral pharmacokinetics during pregnancy must be understood for these drugs to be used safely and effectively in pregnant women. Zidovudine and didanosine, two of the nucleoside reverse transcriptase inhibitors, demonstrate an increase in clearance and decrease in area under the concentration-time curve during pregnancy. The clinical significance of these changes is unknown due to the lack of a clear relationship between plasma concentrations of nucleoside reverse transcriptase inhibitors and clinical effects. Pharmacokinetic parameters of lamivudine, stavudine and abacavir are not significantly changed during pregnancy. There are no data describing the effect of pregnancy on the pharmacokinetics of the other nucleoside/nucleotide analogues (zalcitabine, emtricitabine and tenofovir). Pregnancy does not appear to have a significant effect on the pharmacokinetics of the non-nucleoside reverse transcriptase inhibitor nevirapine and there are no data describing the pharmacokinetics of the other non-nucleoside reverse transcriptase inhibitors (efavirenz and delavirdine) during pregnancy. Reduced plasma concentrations during pregnancy have been described for several of the protease inhibitors, including nelfinavir (with administration of 750 mg three times daily), indinavir, saquinavir and Kaletra (a co-formulation of lopinavir and ritonavir). Plasma concentrations equivalent to those in nonpregnant adults have been reported in pregnant women receiving nelfinavir at doses of 1250 mg twice daily, and the addition of ritonavir to saquinavir greatly increases saquinavir exposure to therapeutic concentrations in pregnant women. No pregnancy pharmacokinetic data are available for the newer protease inhibitors atazanavir and fosamprenavir, or with other dual protease inhibitor combinations that include low dose ritonavir to boost concentrations of the coadministered protease inhibitor. Further investigations of antiretroviral pharmacology during pregnancy, including protein binding studies, are urgently needed.
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Affiliation(s)
- Mark Mirochnick
- Boston University School of Medicine, Boston, Massachusetts 02118, USA.
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Jorajuria S, Clayette P, Dereuddre-Bosquet N, Benlhassan-Chahour K, Thiébot H, Vaslin B, Le Grand R, Dormont D. The expression of P-glycoprotein and cellular kinases is modulated at the transcriptional level by infection and highly active antiretroviral therapy in a primate model of AIDS. AIDS Res Hum Retroviruses 2003; 19:307-11. [PMID: 12804006 DOI: 10.1089/088922203764969500] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The beneficial effects of highly active antiretroviral therapy (HAART) in HIV-infected patients may be limited by inadequate compliance and viral resistance, but also by host cell factors, such as P-glycoprotein (P-gp) and intracellular kinases involved in the phosphorylation of nucleoside reverse transcriptase inhibitors. We investigated the effects of infection and HAART (zidovudine [AZT], lamivudine [3TC], and indinavir [IDV] on the expression of P-gp and cell kinases involved in the phosphorylation of AZT and 3TC in SHIV89.6P-infected cynomolgus macaques. Under unstimulated conditions, we observed a decrease in P-gp mRNA levels in the peripheral blood and lymph node mononuclear cells of infected macaques, which was accentuated by HAART. SHIV infection also resulted in the overexpression of thymidine kinase mRNA, which was abolished by HAART. In conclusion, retroviral infection and HAART modulate in vivo at the transcriptional level the expression of host cell factors that may affect the efficacy of HAART.
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Affiliation(s)
- Sylvie Jorajuria
- CEA, Service de Neurovirologie, DRM/DSV, CRSSA, EPHE, IPSC, 92265 Fontenay-aux-Roses, France
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Becher F, Pruvost A, Goujard C, Guerreiro C, Delfraissy JF, Grassi J, Benech H. Improved method for the simultaneous determination of d4T, 3TC and ddl intracellular phosphorylated anabolites in human peripheral-blood mononuclear cells using high-performance liquid chromatography/tandem mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2002; 16:555-565. [PMID: 11870893 DOI: 10.1002/rcm.605] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
There is still a need for direct determination (i.e. without dephosphorylation) of nucleoside reverse transcriptase inhibitor (NRTI) triphosphorylated nucleotides in the peripheral-blood mononuclear cells (PBMCs) of HIV-positive patients. The objective of this paper was first to improve our previously described direct liquid chromatography/tandem mass spectrometry (LC/MS/MS) assay for stavudine triphosphate (d4T-TP). Preparation of PBMCs was modified to reduce degradation of d4T-TP during cell preparation and to simplify this step for routine use in clinical units. The performance of several HPLC columns was compared in order to improve the stability of peak shape over time. The SMT C(18) column was replaced by a Supelcogel ODP-50, thereby reducing two-fold the concentration of the first standard. Various internal standards were compared to optimize peak shape and remove an interfering peak in LC. 2-Chloroadenosine 5prime prime or minute-triphosphate was chosen as the most appropriate internal standard. Substitution of the narrowbore column by a microbore column (150 x 0.32 mm) is also presented and discussed. Secondly, this improved method was successfully applied to the simultaneous determination of d4T-TP, dideoxyadenosine triphosphate (ddA-TP) and lamivudine triphosphate (3TC-TP) in PBMCs, which is useful in view of the common use of NRTI combinations. The method was subsequently applied to clinical samples from HIV-positive patients receiving antiretroviral therapy containing d4T, ddl and/or 3TC. This method can be used simply and routinely on approximately 200 samples per week, using commercially available instruments and with a simple cell lysis as sample treatment.
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Affiliation(s)
- François Becher
- CEA, Pharmacology and Immunology Unit, DSV/DRM, CEA/Saclay, 91191 Gif-sur-Yvette cedex, France
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Hoggard PG, Lloyd J, Khoo SH, Barry MG, Dann L, Gibbons SE, Wilkins EG, Loveday C, Back DJ. Zidovudine phosphorylation determined sequentially over 12 months in human immunodeficiency virus-infected patients with or without previous exposure to antiretroviral agents. Antimicrob Agents Chemother 2001; 45:976-80. [PMID: 11181396 PMCID: PMC90409 DOI: 10.1128/aac.35.3.976-980.2001] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We sought to determine whether the intracellular activation of zidovudine (ZDV) varied over time and with previous antiretroviral exposure in human immunodeficiency virus-infected individuals and to examine whether there is an association between virological responses and intracellular phosphorylation. A total of 23 patients (12 treatment naïve, 11 previously treated with ZDV) who commenced ZDV as part of dual nucleoside therapy were prospectively monitored for 12 months or until withdrawal from the study. No association was observed between virological responses at 2 weeks and 3 months and ZDV phosphorylation. The mean intracellular concentrations of ZDV mono-, di-, and triphosphates did not change significantly over time or with previous ZDV exposure. The rate of formation of total ZDV phosphates was increased in patients with CD4 counts <100 cells/mm(3). Previous reports from in vitro cell culture experiments or cross-sectional cohort studies suggesting alterations of ZDV phosphorylation over time are not confirmed by this longitudinal study.
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Affiliation(s)
- P G Hoggard
- Department of Pharmacology & Therapeutics, University of Liverpool, Liverpool L69 3GE, United Kingdom.
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