1
|
Hari BV, Narayanan N, Dhevendaran K, Ramyadevi D. Engineered nanoparticles of Efavirenz using methacrylate co-polymer (Eudragit-E100) and its biological effects in-vivo. Materials Science and Engineering: C 2016; 67:522-32. [DOI: 10.1016/j.msec.2016.05.064] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/21/2016] [Accepted: 05/15/2016] [Indexed: 01/12/2023]
|
2
|
Alam C, Whyte-Allman SK, Omeragic A, Bendayan R. Role and modulation of drug transporters in HIV-1 therapy. Adv Drug Deliv Rev 2016; 103:121-143. [PMID: 27181050 DOI: 10.1016/j.addr.2016.05.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [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] [Received: 01/12/2016] [Revised: 04/29/2016] [Accepted: 05/03/2016] [Indexed: 12/15/2022]
Abstract
Current treatment of human immunodeficiency virus type-1 (HIV-1) infection involves a combination of antiretroviral drugs (ARVs) that target different stages of the HIV-1 life cycle. This strategy is commonly referred to as highly active antiretroviral therapy (HAART) or combined antiretroviral therapy (cART). Membrane-associated drug transporters expressed ubiquitously in mammalian systems play a crucial role in modulating ARV disposition during HIV-1 infection. Members of the ATP-binding cassette (ABC) and solute carrier (SLC) transporter superfamilies have been shown to interact with ARVs, including those that are used as part of first-line treatment regimens. As a result, the functional expression of drug transporters can influence the distribution of ARVs at specific sites of infection. In addition, pathological factors related to HIV-1 infection and/or ARV therapy itself can alter transporter expression and activity, thus further contributing to changes in ARV disposition and the effectiveness of HAART. This review summarizes current knowledge on the role of drug transporters in regulating ARV transport in the context of HIV-1 infection.
Collapse
Affiliation(s)
- Camille Alam
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 2S2, Canada
| | - Sana-Kay Whyte-Allman
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 2S2, Canada
| | - Amila Omeragic
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 2S2, Canada
| | - Reina Bendayan
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 2S2, Canada.
| |
Collapse
|
3
|
Apostolova N, Funes HA, Blas-Garcia A, Galindo MJ, Alvarez A, Esplugues JV. Efavirenz and the CNS: what we already know and questions that need to be answered. J Antimicrob Chemother 2015. [PMID: 26203180 DOI: 10.1093/jac/dkv183] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The NNRTI efavirenz has long been one of the most frequently employed antiretroviral drugs in the multidrug regimens used to treat HIV infection, in accordance with its well-demonstrated antiretroviral efficacy and favourable pharmacokinetics. However, growing concern about its adverse effects has sometimes led to efavirenz being replaced by other drugs in the initial treatment selection or to switching of therapy to efavirenz-free regimens in experienced patients. Neurological and neuropsychiatric reactions are the manifestations most frequently experienced by efavirenz-treated patients and range from transitory effects, such as nightmares, dizziness, insomnia, nervousness and lack of concentration, to more severe symptoms including depression, suicidal ideation or even psychosis. In addition, efavirenz has recently been associated with mild/moderate neurocognitive impairment, which is of specific relevance given that half of the patients receiving ART eventually suffer some form of HIV-associated neurocognitive disorder. The mechanisms responsible for efavirenz-induced neurotoxicity are unclear, although growing evidence points to disturbances in brain mitochondrial function and bioenergetics. This review offers a comprehensive overview of the current evidence on the interaction that efavirenz displays with the CNS, including the penetration and concentration of the drug in the brain. We discuss the prevalence, types and specificities of its side effects and recently uncovered cellular mechanisms that may be involved in their development.
Collapse
Affiliation(s)
- Nadezda Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain Facultad de Ciencias de la Salud, Universitat Jaume I, Castellón de la Plana, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Haryes A Funes
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain
| | - Ana Blas-Garcia
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
| | - Maria J Galindo
- Unidad de Enfermedades Infecciosas-Medicina Interna, Hospital Clínico Universitario de Valencia, Valencia, Spain
| | - Angeles Alvarez
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain
| | - Juan V Esplugues
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain CIBERehd (Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas), Valencia, Spain FISABIO-Hospital Universitario Dr Peset, Valencia, Spain
| |
Collapse
|
4
|
Matusali G, Dereuddre-Bosquet N, Le Tortorec A, Moreau M, Satie AP, Mahé D, Roumaud P, Bourry O, Sylla N, Bernard-Stoecklin S, Pruvost A, Le Grand R, Dejucq-Rainsford N. Detection of Simian Immunodeficiency Virus in Semen, Urethra, and Male Reproductive Organs during Efficient Highly Active Antiretroviral Therapy. J Virol 2015; 89:5772-87. [PMID: 25833047 DOI: 10.1128/JVI.03628-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/22/2015] [Indexed: 12/23/2022] Open
Abstract
UNLABELLED A number of men receiving prolonged suppressive highly active antiretroviral therapy (HAART) still shed human immunodeficiency virus (HIV) in semen. To investigate whether this seminal shedding may be due to poor drug penetration and/or viral production by long-lived cells within male genital tissues, we analyzed semen and reproductive tissues from macaques chronically infected with simian immunodeficiency virus mac251 (SIVmac251) who were treated for 4 months with HAART, which was intensified over the last 7 weeks with an integrase inhibitor. We showed that a subset of treated animals continued shedding SIV in semen despite efficient HAART. This shedding was not associated with low antiretroviral drug concentrations in semen or in testis, epididymis, seminal vesicles, and prostate. HAART had no significant impact on SIV RNA in the urethra, whereas it drastically reduced SIV RNA levels in the prostate and vas deferens and to a lesser extent in the epididymis and seminal vesicle. The only detectable SIV RNA-positive cells within the male genital tract after HAART were urethral macrophages. SIV DNA levels in genital tissues were not decreased by HAART, suggesting the presence throughout the male genital tract of nonproductively infected cells. In conclusion, our results demonstrate that 4 months of HAART induced variable and limited control of viral infection in the male reproductive organs, particularly in the urethra, and suggest that infected long-lived cells in the male genital tract may be involved in persistent seminal shedding during HAART. These results pave the way for further investigations of male genital organ infection in long-term-treated infected individuals. IMPORTANCE A substantial subset of men receiving prolonged HAART suppressing viral loads in the blood still harbor HIV in semen, and cases of sexual transmission have been reported. To understand the origin of this persistence, we analyzed the semen and male reproductive tissues from SIV-infected macaques treated with HAART. We demonstrated that persistent seminal shedding was not linked to poor drug penetration in semen or semen-producing prostate, seminal vesicle, epididymis, and testis. We revealed that HAART decreased SIV RNA to various extents in all male genital organs, with the exception of the urethra, in which SIV RNA(+) macrophages were observed despite HAART. Importantly, HAART did not impact SIV DNA levels in the male genital organs. These results suggest that infection of male genital organs, and particularly the urethra, could be involved in the release of virus in semen during HAART.
Collapse
|
5
|
Trezza CR, Kashuba ADM. Pharmacokinetics of antiretrovirals in genital secretions and anatomic sites of HIV transmission: implications for HIV prevention. Clin Pharmacokinet 2014; 53:611-24. [PMID: 24859035 PMCID: PMC4094112 DOI: 10.1007/s40262-014-0148-z] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The incidence of HIV remains alarmingly high in many parts of the world. Prophylactic use of antiretrovirals, capable of concentrating in the anatomical sites of transmission, may reduce the risk of infection after an unprotected sexual exposure. To date, orally and topically administered antiretrovirals have exhibited variable success in preventing HIV transmission in large-scale clinical trials. Antiretroviral mucosal pharmacokinetics may help explain the outcomes of these investigations. Penetration and accumulation of antiretrovirals into sites of transmission can influence dosing strategies and pre-exposure prophylaxis clinical trial design. Antiretroviral tissue distribution varies widely within and between drug classes, attributed in part to their physicochemical properties and tissue-specific drug transporter expression. Nucleoside(-tide) reverse transcriptase inhibitors, the CCR5 antagonist maraviroc, and the integrase inhibitor raltegravir demonstrate the highest penetration into the male and female reproductive tracts and colorectal tissue relative to blood. This review describes antiretroviral exposure in anatomic sites of transmission, and places these findings in context with the prevention of HIV and the efficacy of pre-exposure prophylactic strategies.
Collapse
Affiliation(s)
- Christine R. Trezza
- University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC
| | - Angela D. M. Kashuba
- University of North Carolina at Chapel Hill, Eshelman School of Pharmacy, Chapel Hill, NC
| |
Collapse
|
6
|
Funes HA, Apostolova N, Alegre F, Blas-Garcia A, Alvarez A, Marti-Cabrera M, Esplugues JV. Neuronal bioenergetics and acute mitochondrial dysfunction: a clue to understanding the central nervous system side effects of efavirenz. J Infect Dis 2014; 210:1385-95. [PMID: 24813473 DOI: 10.1093/infdis/jiu273] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Neurological pathogenesis is associated with mitochondrial dysfunction and differences in neuronal/glial handling of oxygen and glucose. The main side effects attributed to efavirenz involve the CNS, but the underlying mechanisms are unclear. METHODS Human cell lines and rat primary cultures of neurons and astrocytes were treated with clinically relevant efavirenz concentration. RESULTS Efavirenz alters mitochondrial respiration, enhances reactive oxygen species generation, undermines mitochondrial membrane potential, and reduces adenosine triphosphate (ATP) levels in a concentration-dependent fashion in both neurons and glial cells. However, it activates adenosine monophosphate-activated protein kinase only in glial cells, upregulating glycolysis and increasing intracellular ATP levels, which do not occur in neurons. To reproduce the conditions that often exist in human immunodeficiency virus-related neuroinflammatory disorders, the effects of efavirenz were evaluated in the presence of exogenous nitric oxide, an inflammatory mediator and mitochondrial inhibitor. The combination potentiated the effects on mitochondrial parameters in both neurons and glial cells, but ATP generation and lactate production were enhanced only in glial cells. CONCLUSIONS Efavirenz affects the bioenergetics of neurons through a mechanism involving acute mitochondrial inhibition, an action exacerbated in neuroinflammatory conditions. A similar scenario of glial cells survival and degeneration of neurons with signs of mitochondrial dysfunction and oxidative stress has been associated with neurocognitive disorders.
Collapse
Affiliation(s)
- Haryes A Funes
- Departamento de Farmacología, Facultad de Medicina FISABIO-Hospital Universitario Dr. Peset
| | - Nadezda Apostolova
- CIBERehd, Valencia Facultad de Ciencias de la Salud, Universidad Jaime I, Castellón de la Plana, Spain
| | - Fernando Alegre
- Departamento de Farmacología, Facultad de Medicina FISABIO-Hospital Universitario Dr. Peset
| | - Ana Blas-Garcia
- Departamento de Farmacología, Facultad de Medicina FISABIO-Hospital Universitario Dr. Peset
| | - Angeles Alvarez
- Departamento de Farmacología, Facultad de Medicina Fundación General, Universidad de Valencia CIBERehd, Valencia
| | | | - Juan V Esplugues
- Departamento de Farmacología, Facultad de Medicina FISABIO-Hospital Universitario Dr. Peset CIBERehd, Valencia
| |
Collapse
|
7
|
DiFrancesco R, Maduke G, Patel R, Taylor CR, Morse GD. Antiretroviral bioanalysis methods of tissues and body biofluids. Bioanalysis 2013; 5:351-68. [PMID: 23394701 DOI: 10.4155/bio.12.319] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Research in the many areas of HIV treatment, eradication and prevention has necessitated measurement of antiretroviral (ARV) concentrations in nontraditional specimen types. To determine the knowledgebase of critical details for accurate bioanalysis, a review of the literature was performed and summarized. Bioanalytical assays for 31 ARVs, including metabolites, were identified in 205 publications measuring various tissues and biofluids. 18 and 30% of tissue or biofluid methods, respectively, analyzed more than one specimen type; 35-37% of the tissue or biofluid methods quantitated more than one ARV. 20 and 76% of tissue or biofluid methods, respectively, were used for the analysis of human specimens. HPLC methods with UV detection predominated, but chronologically MS detection began to surpass. 40% of the assays provided complete intra- and inter-assay validation data, but only 9% of publications provided any stability data with even less for the prevalent ARV in treatments.
Collapse
|
8
|
Graham SM, Holte SE, Dragavon JA, Ramko KM, Mandaliya KN, McClelland RS, Peshu NM, Sanders EJ, Krieger JN, Coombs RW. HIV-1 RNA may decline more slowly in semen than in blood following initiation of efavirenz-based antiretroviral therapy. PLoS One 2012; 7:e43086. [PMID: 22912795 PMCID: PMC3418270 DOI: 10.1371/journal.pone.0043086] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/16/2012] [Indexed: 11/29/2022] Open
Abstract
Objectives Antiretroviral therapy (ART) decreases HIV-1 RNA levels in semen and reduces sexual transmission from HIV-1-infected men. Our objective was to study the time course and magnitude of seminal HIV-1 RNA decay after initiation of efavirenz-based ART among 13 antiretroviral-naïve Kenyan men. Methods HIV-1 RNA was quantified (lower limit of detection, 120 copies/mL) in blood and semen at baseline and over the first month of ART. Median log10 HIV-1 RNA was compared at each time-point using Wilcoxon Signed Rank tests. Perelson’s two-phase viral decay model and nonlinear random effects were used to compare decay rates in blood and semen. Results Median baseline HIV-1 RNA was 4.40 log10 copies/mL in blood (range, 3.20–5.08 log10 copies/mL) and 3.69 log10 copies/mL in semen (range, <2.08–4.90 log10 copies/mL). The median reduction in HIV-1 RNA by day 28 was 1.90 log10 copies/mL in blood (range, 0.56–2.68 log10 copies/mL) and 1.36 log10 copies/mL in semen (range, 0–2.66 log10 copies/mL). ART led to a decrease from baseline by day 7 in blood and day 14 in semen (p = 0.005 and p = 0.006, respectively). The initial modeled decay rate was slower in semen than in blood (p = 0.06). There was no difference in second-phase decay rates between blood and semen. Conclusions Efavirenz-based ART reduced HIV-1 RNA levels more slowly in semen than in blood. Although this difference was of borderline significance in this small study, our observations suggest that there is suboptimal suppression of seminal HIV-1 RNA for some men in the early weeks of treatment.
Collapse
Affiliation(s)
- Susan M Graham
- Department of Medicine, University of Washington, Seattle, Washington, United States of America.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Else LJ, Taylor S, Back DJ, Khoo SH. Pharmacokinetics of antiretroviral drugs in anatomical sanctuary sites: the male and female genital tract. Antivir Ther 2012; 16:1149-67. [PMID: 22155899 DOI: 10.3851/imp1919] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
HIV resides within anatomical 'sanctuary sites', where local drug exposure and viral dynamics may differ significantly from the systemic compartment. Suboptimal antiretroviral concentrations in the genital tract may result in compartmentalized viral replication, selection of resistant mutations and possible re-entry of wild-type/resistant virus into the systemic circulation. Therefore, achieving adequate antiretroviral exposure in the genital tract has implications for the prevention of sexual and vertical transmission of HIV. Penetration of antiretrovirals in the genital tract is expressed by accumulation ratios derived from the measurement of drug concentrations in time-matched seminal plasma/cervicovaginal fluid and plasma samples. Penetration varies by gender and may be drug (as opposed to class) specific with high interindividual variability. Concentrations in seminal plasma are highest for nucleoside analogues and lowest for protease inhibitors and efavirenz. Seminal accumulation of newer agents, raltegravir and maraviroc, is moderate (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitors [lamivudine/zidovudine/tenofovir/didanosine > stavudine/abacavir] > raltegravir > indinavir/maraviroc/nevirapine >> efavirenz/protease inhibitors [amprenavir/atazanavir/darunavir > lopinavir/ritonavir > saquinavir] > enfuvirtide). In the female genital tract, the nucleoside analogues exhibit high accumulation ratios, whereas protease inhibitors have limited penetration; however, substantial variability exists between individuals and study centres. Second generation non-nucleoside reverse transcriptase inhibitor etravirine, and maraviroc and raltegravir, demonstrate effective accumulation in cervicovaginal secretions (rank order of accumulation is nucleoside/nucleotide reverse transcriptase inhibitor [zidovudine/lamivudine/didanosine > emtricitabine/tenofovir] > indinavir > maraviroc/raltegravir/darunavir/etravirine > nevirapine/abacavir > protease inhibitors [amprenavir/atazanavir/ritonavir] > lopinavir/stavudine/efavirenz > saquinavir).
Collapse
Affiliation(s)
- Laura J Else
- Department of Molecular and Clinical Pharmacology, University of Liverpool, Liverpool, UK.
| | | | | | | |
Collapse
|
10
|
Ananworanich J, Kerr SJ, Vernazza P, Mangclaviraj S, Chaithongwongwatthana S, Chotnopparatpattara P, Mahanontharit A, Ubolyam S, Jupimai T, Cooper DA, Ruxrungtham K, Hirschel B. Genital shedding of HIV after scheduled treatment interruption. Int J STD AIDS 2011; 22:61-6. [PMID: 21427425 DOI: 10.1258/ijsa.2010.009594] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This study assessed genital shedding of HIV in patients on intermittent combination antiretroviral therapy (cART) and assessed predictors of having detectable genital HIV RNA in 156 Thai patients with CD4 > 350 cells/μL and HIV RNA ≤50 copies/mL who were randomized to continuous therapy (CT, n = 65) or CD4-guided cART (n = 91). There were 383 matched genital and plasma HIV RNA samples (CT: 158, CD4 guided: 225). In 14 samples collected within eight weeks of treatment interruption, detectable HIV RNA was present in 29% of genital samples and 71% of plasma samples. In 55 samples collected after eight weeks of treatment interruption, detectable HIV RNA was present in 60% of genital samples and 98% of plasma samples. In 110 samples collected up to 96 weeks after treatment re-initiation, detectable genital HIV RNA was found in 8% of samples and all of these were within the first 17 weeks. Independent predictors of detectable genital HIV RNA were increasing age and increasing concentrations of HIV RNA in plasma. These findings support the role of cART in maintaining undetectable HIV RNA in genital secretions.
Collapse
Affiliation(s)
- J Ananworanich
- The HIV Netherlands Australia Thailand Research Collaboration, Bangkok, Thailand.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Abstract
Many antiretroviral (ARV) drugs have large blood plasma-to-seminal plasma (BP/SP) concentration ratios. Concern exists that these drugs do not adequately penetrate the male genital tract (MGT), resulting in the MGT becoming a "pharmacological sanctuary" from these agents, with ineffective MGT concentrations despite effective blood concentrations. Efavirenz (EFV) is the most highly protein-bound ARV drug, with >99% binding in blood plasma and the largest BP/SP total EFV concentration ratio, reportedly ranging from 11 to 33. To evaluate protein binding as an explanation for the differences between the drug concentrations in blood and semen, we developed a novel ultrafiltration method, corrected for the duration of centrifugation, to measure protein binding in the two matrices. In six subjects, protein-free EFV concentrations were the same in blood and semen; the median (interquartile range (IQR)) protein-free EFV SP/BP ratio was 1.21 (0.99-1.35); EFV protein binding was 99.82% (99.79-99.86) in BP and 95.26% (93.24-96.67) in SP. This shows that the MGT is not a sanctuary from EFV.
Collapse
|
12
|
Apostolova N, Gomez-Sucerquia LJ, Moran A, Alvarez A, Blas-Garcia A, Esplugues JV. Enhanced oxidative stress and increased mitochondrial mass during efavirenz-induced apoptosis in human hepatic cells. Br J Pharmacol 2010; 160:2069-84. [PMID: 20649602 DOI: 10.1111/j.1476-5381.2010.00866.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Efavirenz (EFV) is widely used in the treatment of HIV-1 infection. Though highly efficient, there is growing concern about EFV-related side effects, the molecular basis of which remains elusive. EXPERIMENTAL APPROACH In vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 microM) on human hepatic cells. KEY RESULTS Cellular proliferation and viability were reduced in a concentration-dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect. CONCLUSION AND IMPLICATIONS Clinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.
Collapse
Affiliation(s)
- N Apostolova
- Departamento de Farmacología, Facultad de Medicina, Universidad de Valencia, Valencia, Spain.
| | | | | | | | | | | |
Collapse
|
13
|
Taylor S, Davies S. Antiretroviral drug concentrations in the male and female genital tract: implications for the sexual transmission of HIV. Curr Opin HIV AIDS 2010; 5:335-43. [PMID: 20543610 DOI: 10.1097/COH.0b013e32833a0b69] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW To summarize the recent literature (2008-2010) on antiretroviral (ARV) drug disposition into the male and female genital tract. RECENT FINDINGS Recent studies have confirmed that penetration of antiretroviral agents into the male and female genital tracts are both drug and sex specific. Concentrations achieved vary considerably depending on the class of drug studied, the sampling techniques used and the times samples are obtained. SUMMARY There appear to be several patterns of drug penetration into the male and female genital tract. In addition there appear to be different patterns of genital shedding under the influence of antiretroviral therapy. What effect these factors will have on the sexual transmission of HIV or the evolution and transmission of resistant HIV remains to be seen.
Collapse
|
14
|
Kis O, Robillard K, Chan GN, Bendayan R. The complexities of antiretroviral drug-drug interactions: role of ABC and SLC transporters. Trends Pharmacol Sci 2010; 31:22-35. [PMID: 20004485 DOI: 10.1016/j.tips.2009.10.001] [Citation(s) in RCA: 180] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Revised: 09/30/2009] [Accepted: 10/01/2009] [Indexed: 12/15/2022]
Abstract
Treatment of human immunodeficiency virus (HIV) infection involves a combination of several antiviral agents belonging to different pharmacological classes. This combination is referred to as highly active antiretroviral therapy (HAART). This treatment has proved to be very effective in suppressing HIV replication, but antiretroviral drugs have complex pharmacokinetic properties involving extensive drug metabolism and transport by membrane-associated drug carriers. Combination drug therapy often introduces complex drug-drug interactions that can result in toxic or sub-therapeutic drug concentrations, compromising treatment. This review focuses on the role of ATP-binding cassette (ABC) membrane-associated efflux transporters and solute carrier (SLC) uptake transporters in antiretroviral drug disposition, and identifies clinically important antiretroviral drug-drug interactions associated with changes in drug transport.
Collapse
|
15
|
Dinoso JB, Kim SY, Wiegand AM, Palmer SE, Gange SJ, Cranmer L, O'Shea A, Callender M, Spivak A, Brennan T, Kearney MF, Proschan MA, Mican JM, Rehm CA, Coffin JM, Mellors JW, Siliciano RF, Maldarelli F. Treatment intensification does not reduce residual HIV-1 viremia in patients on highly active antiretroviral therapy. Proc Natl Acad Sci U S A 2009; 106:9403-8. [PMID: 19470482 DOI: 10.1073/pnas.0903107106] [Citation(s) in RCA: 347] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In HIV-1-infected individuals on currently recommended antiretroviral therapy (ART), viremia is reduced to <50 copies of HIV-1 RNA per milliliter, but low-level residual viremia appears to persist over the lifetimes of most infected individuals. There is controversy over whether the residual viremia results from ongoing cycles of viral replication. To address this question, we conducted 2 prospective studies to assess the effect of ART intensification with an additional potent drug on residual viremia in 9 HIV-1-infected individuals on successful ART. By using an HIV-1 RNA assay with single-copy sensitivity, we found that levels of viremia were not reduced by ART intensification with any of 3 different antiretroviral drugs (efavirenz, lopinavir/ritonavir, or atazanavir/ritonavir). The lack of response was not associated with the presence of drug-resistant virus or suboptimal drug concentrations. Our results suggest that residual viremia is not the product of ongoing, complete cycles of viral replication, but rather of virus output from stable reservoirs of infection.
Collapse
|
16
|
Politch JA, Mayer KH, Anderson DJ. Depletion of CD4+ T cells in semen during HIV infection and their restoration following antiretroviral therapy. J Acquir Immune Defic Syndr 2009; 50:283-9. [PMID: 19194315 DOI: 10.1097/QAI.0b013e3181989870] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Information concerning the effects of HIV-1 infection, disease progression, and antiretroviral therapy (ART) on male genital white blood cell (WBC) profiles could provide important insight into genital immune defense in HIV-infected men and seminal HIV transmission mechanisms. OBJECTIVE To compare concentrations of WBC populations in semen from HIV-1-seronegative (HIV) and HIV-1-seropositive (HIV) men and determine whether HIV disease stage and ART are associated with alterations in seminal WBC profiles. SUBJECTS AND METHODS Subjects were 102 HIV men, 98 ART-naive (ART) HIV men, and 22 HIV men on dual nucleoside ART, before and 6 months after addition of indinavir. Seminal WBCs, macrophages (MØ), and T-lymphocyte subpopulations were enumerated by immunohistology technique. RESULTS Seminal CD4 and CD8 T-cell populations were severely depleted in most ART HIV men regardless of peripheral blood CD4 cell count. Seminal MØ counts were reduced by 50%. HIV men on dual nucleoside ART had significantly higher seminal MØ, CD4, and CD8 T-cell counts than ART HIV men; addition of indinavir led to a dramatic (>25-fold, P < 0.001) increase in seminal CD4 T-cell counts which paralleled an increase in blood CD4 cell counts. Two outlier ART HIV men with notably elevated seminal WBC profiles (>20 x 10 WBCs/mL) and infectious cell-associated HIV in semen are described. CONCLUSIONS HIV infection severely depletes CD4 T cells in the male genital tract as it does at other mucosal sites. This provides evidence that ART HIV men have depressed T cell-dependent genital immune defense functions and are vulnerable to other genital infections that could promote HIV transmission. Seminal CD4 T-cell counts rebounded after treatment with a viral-suppressing ART regimen, indicating that ART may reverse HIV-associated genital immunosuppression. The relative abundance of seminal MØ in HIV men suggests that these cells may be predominant HIV host cells in the male genital tract and vectors of HIV transmission. A subgroup of HIV men with exceptionally elevated seminal MØ and CD4 T-cell counts and HIV titers may be highly infectious and contribute disproportionately to HIV transmission.
Collapse
|
17
|
Abstract
Guidelines for use of antiretroviral agents presently recommend first-line treatments with nonnucleoside reverse transcriptase inhibitor-based regimens. Efavirenz is the standard-of-care comparator for nonnucleoside reverse transcriptase inhibitor-based antiretroviral therapy. As with many antiretroviral medications, efavirenz is subject to interindividual variation in metabolism, effectiveness, and tolerability. Demographic factors such as age, sex, and ethnicity have been demonstrated to influence this variability, but other underlying factors such as genetics, disease state, and concomitant drug use can also play a role. The clinical impactions of these factors are only beginning to be understood. Although significant advances have led to a greater understanding of interactions between genetic and host factors that influence the efficacy and toxicity of efavirenz, providers should not withhold treatment of HIV infection with an efavirenz-based regimen on the basis of racial or ethic categorizations.
Collapse
|
18
|
Abstract
HIV is a devastating disease caused by the human immunodeficiency virus. Symptoms of illness can manifest in every organ system, including the skin. Although there is no definitive cure, the creation of antiretroviral drugs and aggressive treatment regimens have dramatically altered disease morbidity and mortality. However, the precise drug selection is often difficult and intimidating given the sheer abundance of drug therapies available. In this article, the HIV disease course is reviewed and different classes of antiretroviral medications are presented with emphasis on initial drug regimens, potential adverse effects, particularly those of dermatologic nature, possible drug interactions, patient compliance, and the emergence of drug resistance.
Collapse
Affiliation(s)
- Yuchi C Chang
- Department of Internal Medicine, University of Texas Health Science Center, Houston, TX 77030, USA
| | | |
Collapse
|
19
|
Ghosn J, Chaix ML, Peytavin G, Rey E, Bresson JL, Goujard C, Katlama C, Viard JP, Tréluyer JM, Rouzioux C. Penetration of enfuvirtide, tenofovir, efavirenz, and protease inhibitors in the genital tract of HIV-1-infected men. AIDS 2004; 18:1958-61. [PMID: 15353984 DOI: 10.1097/00002030-200409240-00014] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
One likely mechanism of virological failure is poor antiretroviral drug diffusion in sites of viral replication such as the genital tract. We measured antiretroviral drug concentrations in blood and semen in 13 HIV-infected men failing treatment. Enfuvirtide did not cross the blood-testis barrier, whereas tenofovir accumulated in semen. Unlike indinavir, semen concentrations of lopinavir, amprenavir, saquinavir and efavirenz were ineffective. These are worrying findings, because suboptimal semen drug concentrations may enhance the risk of sexually transmitted drug-resistant HIV variants.
Collapse
Affiliation(s)
- Jade Ghosn
- Laboratoire de Virologie, EA MRT 3620 Université René Descartes, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Medeiros RP, Munerato P, Diaz RS. HIV-1 viral load in blood and semen plasma of Brazilian patients under antiretroviral therapy. J Clin Virol 2004; 30:346-7. [PMID: 15163426 DOI: 10.1016/j.jcv.2004.02.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2003] [Indexed: 10/26/2022]
|
21
|
Lowe SH, Sankatsing SUC, Repping S, van der Veen F, Reiss P, Lange JMA, Prins JM. Is the male genital tract really a sanctuary site for HIV? Arguments that it is not. AIDS 2004; 18:1353-62. [PMID: 15199311 DOI: 10.1097/01.aids.0000125979.64033.96] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Selwyn H Lowe
- Department of Internal Medicine, Tropical Medicine and AIDS, International Antiviral Therapy Evaluation Center (IATEC), University of Amsterdam, Amsterdam, the Netherlands.
| | | | | | | | | | | | | |
Collapse
|
22
|
Ghosn J, Viard JP, Katlama C, de Almeida M, Tubiana R, Letourneur F, Aaron L, Goujard C, Salmon D, Leruez-Ville M, Rouzioux C, Chaix ML. Evidence of genotypic resistance diversity of archived and circulating viral strains in blood and semen of pre-treated HIV-infected men. AIDS 2004; 18:447-57. [PMID: 15090797 DOI: 10.1097/00002030-200402200-00011] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To study the genetic diversity of drug-resistant HIV strains present in blood and in semen, especially those archived in peripheral blood mononuclear cells (PBMC) and non-sperm cells (NSC). METHODS Paired blood and semen samples were collected from twenty heavily pre-treated HIV-infected men. HIV RNA in blood plasma (BP) and seminal plasma (SP), as well as proviral DNA in PBMC and NSC were quantified and used for resistance genotyping. Phylogenetic analysis of protease gene clones was used to explore the diversity of the viral quasi-species. RESULTS Median BP HIV RNA, PBMC proviral DNA, SP HIV RNA and non-sperm cell proviral DNA loads were respectively: 4.77, 3.65, 3.16 and 1.77 log10 copies per ml or per 10 cells. Resistant HIV strains were found in the BP and PBMC of all the patients, in the SP of 14 patients, and in the NSC of five patients. Overall, the blood and genital compartments exhibited different genotypic resistance patterns in six patients (30%), with additional resistance mutations in the semen of four patients. Phylogenetic analysis of clones of HIV protease gene showed that viral strains in SP originated not only from passive diffusion from BP, but also from local production in semen. The storage of archived proviruses differed according to the anatomic reservoir. CONCLUSION HIV resistant strains are frequent (70%) in the semen of heavily pre-treated men, and the diversity of genotypic resistance pattern confirms HIV compartmentalization. Thus, the risk of sexual transmission of resistant strains can only be partly predicted by standard tests applied to BP.
Collapse
Affiliation(s)
- Jade Ghosn
- Laboratoire de Virologie, EA MRT 3620 Université R. Descartes, CHU Necker, Paris.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Abstract
UNLABELLED Lopinavir is a novel protease inhibitor (PI) developed from ritonavir. Coadministration with low-dose ritonavir significantly improves the pharmacokinetic properties and hence the activity of lopinavir against HIV-1 protease. Coformulated lopinavir/ritonavir was developed for ease of administration and to ensure both drugs are taken together, as part of combination therapy with other antiretroviral agents. Coformulated lopinavir/ritonavir-based regimens provide adequate and durable suppression of viral load and sustained improvements in CD4+ cell counts, as demonstrated in randomised trials in antiretroviral therapy-naive and -experienced adults and children. To date, development of primary resistance to lopinavir/ritonavir has not been observed in 470 antiretroviral therapy-naive patients treated for >48 weeks. The lopinavir/ritonavir-based regimen was more effective than nelfinavir in antiretroviral therapy-naive HIV-1-infected patients in a phase III trial. The coformulation is also effective as 'salvage' therapy, as shown by low cross-resistance rates in patients who failed to respond to treatment with other PIs in phase II trials. Coformulated lopinavir/ritonavir was well tolerated in both antiretroviral therapy-naive and -experienced HIV-1-infected adults and children with low rates of study drug-related treatment discontinuations. The most common adverse event in adults associated with lopinavir/ritonavir was diarrhoea, followed by other gastrointestinal disturbances, asthenia, headache and skin rash. The incidence of moderate-to-severe adverse events in children was low, skin rash being the most common. Changes in body fat composition occurred with equal frequency in lopinavir/ritonavir- and nelfinavir-treated naive patients, through week 60 in a phase III study. Although laboratory abnormalities occurred with similar frequency in both treatment groups, triglycerides grade 3/4 elevations were significantly more frequent with lopinavir/ritonavir. Total cholesterol and triglycerides grade 3/4 elevations appear to occur more frequently in PI-experienced than in PI-naive lopinavir/ritonavir-treated patients. A number of clinically important drug interactions have been reported with lopinavir/ritonavir necessitating dosage adjustments of lopinavir/ritonavir and/or the interacting drugs, and several other drugs are contraindicated in patients receiving the coformulation. CONCLUSION Coformulated lopinavir/ritonavir is a novel PI that, in combination with other antiretroviral agents, suppresses plasma viral load and enhances immunological status in therapy-naive and -experienced patients with HIV-1 infection. Lopinavir/ritonavir appears more effective than nelfinavir in 'naive' patients and is also suitable for 'salvage' therapy, because of its high barrier to development of resistance. Given its clinical efficacy, a tolerability profile in keeping with this class of drugs, favourable resistance profile and easy-to-adhere-to administration regimen, coformulated lopinavir/ritonavir should be regarded as a first-line option when including a PI in the management of HIV-1 infection. OVERVIEW OF PHARMACODYNAMIC PROPERTIES Lopinavir/ritonavir is a coformulation of two structurally related protease inhibitor (PI) antiretroviral agents. Lopinavir is a highly potent and selective inhibitor of the HIV type 1 (HIV-1) protease, an essential enzyme for production of mature, infective virus. It acts by arresting maturation of HIV-1 thereby blocking its infectivity. Thus, the main antiviral action of lopinavir is to prevent subsequent infections of susceptible cells; it has no effect on cells with already integrated viral DNA. Lopinavir has an approximate, equals 10-fold higher in vitro activity against both wild-type and mutant HIV-1 proteases than ritonavir; however, its in vivo activity is greatly attenuated by a high first-pass hepatic metabolism. The low-dose ritonavir coadministered with lopinavir inhibits metabolic inactivation of lopinavir and acts only as its pharmacokinetic enhancer. Therefore, the antiretroviral activity of roviral activity of coformulated lopinavir/ritonavir 400/100mg twice daily is derived solely from lopinavir plasma concentrations. Combining lopinavir with low-dose ritonavir produces lopinavir concentrations far exceeding those needed to suppress 50% of in vitro and in vivo viral replication in CD4+ cells and monocyte/macrophages (main human reservoirs of HIV-1 infection). Thus far, no resistance to lopinavir has been detected in clinical trials in antiretroviral therapy-naive patients treated for up to 204 weeks and only 12% of HIV-1 strains from patients in whom prior treatment with multiple PIs have failed, have been observed to develop resistance to coformulated lopinavir/ritonavir. A strong negative correlation was found between the number of PI mutations at baseline and the viral response rates achieved with lopinavir/ritonavir-based regimens in PI-experienced patients, indicating that resistance to lopinavir increases with increasing number of PI mutations and that five PI mutations represent the clinically relevant genotypic breakpoint for lopinavir. OVERVIEW OF PHARMACOKINETIC PROPERTIES The absolute bioavailability of lopinavir coformulated with ritonavir in humans has not yet been established. Multiple-dosage absorption pharmacokinetics of lopinavir/ritonavir 400/100mg twice daily (the mean peak [C(max)] and trough [C(trough)] plasma concentrations at steady-state and the 12-hour area under the plasma concentration-time curve [AUC(12)] of either drug) were stable in antiretroviral therapy-naive and single PI-experienced adult patients receiving therapy over a 24-week evaluation period. The C(trough) values of lopinavir, achieved with lopinavir/ritonavir 400/100mg twice daily, were median 84-fold higher than the protein binding-adjusted 50% effective concentration (EC(50)) of lopinavir against wild-type HIV-1 in antiretroviral therapy-naive HIV-1-infected patients in a phase II study. Bioavailability of lopinavir administered in either the capsule or the liquid lopinavir/ritonavir formulation can be increased substantially with concurrent ingestion of food with moderate-to-high fat content. At steady state, lopinavir is approximately 98-99% plasma protein bound and the percentage of its unbound (i.e. pharmacologically active) fraction is dependent on total drug plasma concentration. Both lopinavir and ritonavir penetrate poorly into the human genital tracts and the cerebrospinal fluid. Both agents undergo extensive and rapid first-pass metabolism by hepatic cytochrome P450 (CYP) 3A4 isoenzyme. However, ritonavir also potently inhibits this enzyme and acts as a pharmacokinetic enhancer of lopinavir. The elimination half-life and apparent oral clearance of lopinavir average approximately 4-6 hours and approximately 6-7 L/h, respectively, with lopinavir/ritonavir 400/100mg twice daily administration. Less than 3% and 20% of the lopinavir dose is excreted unchanged in the urine and faeces, respectively. Limited data show similar pharmacokinetics of lopinavir in children as in adults. DRUG INTERACTIONS Coformulated lopinavir/ritonavir has the potential to interact with wide variety of drugs via several mechanisms, mostly involving the CYP enzymes. Coadministration of lopinavir/ritonavir is contraindicated with certain drugs (i.e. flecainide, propafenone, astemizole, terfenadine, ergot derivatives, cisapride, pimozide, midazolam and triazolam) that are highly dependent on CYP3A or CYP2D6 for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events. Coadministration with lopinavir/ritonavir is also not recommended for drugs or herbal products (i.e. rifampicin [rifampin] and St. John's wort [Hypericum perforatum]) that may substantially reduce lopinavir plasma concentrations, or drugs whose plasma concentrations elevated by the coformulation may lead to serious adverse reactions (i.e. simvastatin and lovastatin). However, a recent study in healthy volunteers suggests that adequate lopinavir concentrations may be achieved during rifampicin coadministration by increasing the twice-daily dosage of lopinavir/ritonavir in conjunction with therapeutic drug monitoring. The liquid (but not the capsule) formulation of lopinavir/ritonavir contains 42.4% ethanol (v/v) and should not be coadministered with drugs capable of producing disulfiram-like reactions (e.g. disulfiram, metronidazole). Coadministration with saquinavir or indinavir requires no dosage adjustment, whereas coadministration with amprenavir, nevirapine or efavirenz requires a dosage increase of the coformulation typically by 33%. As the oral bioavailability of both didanosine and lopinavir/ritonavir is significantly affected by concurrent food ingestion, didanosine should be administered 1 hour before or 2 hours after lopinavir/ritonavir has been taken with food. Interactions between lopinavir/ritonavir and other nucleoside reverse transcriptase inhibitors (NRTIs) are not expected. The coformulation is also likely to increase plasma concentrations of non-antiretroviral drugs metabolised through the CYP3A pathway. To reduce the risk of their toxicity when coadministered with lopinavir/ritonavir, the recommended actions include: (i) monitoring of the drug plasma concentration (antiarrhythmics and immunosuppressants) or the international normalised ratio (warfarin); (ii) the use of alternative treatment (atorvastatin) or birth control methods (ethinylestradiol); and (iii) dosage adjustment (clarithromycin [only in patients with renal failure], rifabutin, dihydropyridine calcium-channel blockers, atorvastatin, ketoconazole and itraconazole). (ABSTRACT TRUNCATED)
Collapse
|
24
|
Ward BA, Gorski JC, Jones DR, Hall SD, Flockhart DA, Desta Z. The cytochrome P450 2B6 (CYP2B6) is the main catalyst of efavirenz primary and secondary metabolism: implication for HIV/AIDS therapy and utility of efavirenz as a substrate marker of CYP2B6 catalytic activity. J Pharmacol Exp Ther 2003; 306:287-300. [PMID: 12676886 DOI: 10.1124/jpet.103.049601] [Citation(s) in RCA: 454] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We used human liver microsomes (HLMs) and recombinant cytochromes P450 (P450s) to identify the routes of efavirenz metabolism and the P450s involved. In HLMs, efavirenz undergoes primary oxidative hydroxylation to 8-hydroxyefavirenz (major) and 7-hydroxyefavirenz (minor) and secondary metabolism to 8,14-dihydroxyefavirenz. The formation of 8-hydroxyefavirenz in two HLMs showed sigmoidal kinetics (average apparent Km, 20.2 micro M; Vmax, 140 pmol/min/mg protein; and Hill coefficient, 1.5), whereas that of 7-hydroxyefavirenz formation was characterized by hyperbolic kinetics (Km, 40.1 micro M and Vmax, 20.5 pmol/min/mg protein). In a panel of 10 P450s, CYP2B6 formed 8-hydroxyefavirenz and 8,14-dihydroxyefavirenz from efavirenz (10 micro M) at the highest rate. The Km value for the formation of 8-hydroxyefavirenz in CYP2B6 derived from hyperbolic Eq. 12.4 micro M) was close to that obtained in HLMs (Km, 20.2 micro M). None of the P450s tested showed activity toward 7-hydroxylation of efavirenz. When 8-hydroxyefavirenz (2.5 micro M) was used as a substrate, 8,14-dihydroxyefavirenz was formed by CYP2B6 at the highest rate, and its kinetics showed substrate inhibition (Ksi, approximately 94 micro M in HLMs and approximately 234 micro M in CYP2B6). In a panel of 11 HLMs, 8-hydroxyefavirenz and 8,14-dihydroxyefavirenz formation rates from efavirenz (10 micro M) correlated significantly with the activity of CYP2B6 and CYP3A. N,N',N"-Triethylenethiophosphoramide (thioTEPA; 50 micro M) inhibited the formation rates of 8-hydroxyefavirenz and 8,14-dihydroxyefavirenz from efavirenz (10 micro M) by > or = 60% in HLMs) and CYP2B6, with Ki values < 4 micro M. In conclusion, CYP2B6 is the principal catalyst of efavirenz sequential hydroxylation. Efavirenz systemic exposure is likely to be subject to interindividual variability in CYP2B6 activity and to drug interactions involving this isoform. Efavirenz may be a valuable phenotyping tool to study the role of CYP2B6 in human drug metabolism.
Collapse
Affiliation(s)
- Bryan A Ward
- Department of Medicine, Division of Clinical Pharmacology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | |
Collapse
|
25
|
Sankatsing SUC, Droste J, Burger D, Van Praag RME, Jurriaans S, Lange JMA, Prins JM. Limited penetration of lopinavir into seminal plasma of HIV-1-infected men. AIDS 2002; 16:1698-700. [PMID: 12172099 DOI: 10.1097/00002030-200208160-00023] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Abstract
The increased incidence of HIV/AIDS disease in women aged 15 - 49 years has identified the urgent need for a female-controlled, efficacious and safe vaginal topical microbicide. To meet this challenge, new topical microbicide candidates consisting of molecules or formulations that modify the genital environment (BufferGel, engineered Lactobacillus, over-the-counter lubricants), surfactants (C31D/Savvy, sodium dodecyl sulfate, sodium lauryl sulfate), polyanionic polymers (PRO 2000, beta-cyclodextrin, Carraguard, CAP, D2S, SPL-7013), proteins (cyanovirin-N, monoclonal antibodies, thromspondin-1 peptides, Pokeweed antiviral protein and others), reverse transcription inhibitors (PMPA [Tenofovir ]), UC-781, SJ-3366, DABO and thiourea) and other molecules (NCp7-specific virucides, chemokine receptor agonists/antagonists, WHI-05 and WHI-07) are currently being investigated for activity, safety and efficacy. This review will assess the development of these molecules in the context of cervicovaginal defences and the clinical failure of nonoxynol-9.
Collapse
Affiliation(s)
- Jim A Turpin
- TherImmune Research Corporation, Infectious Disease and Immunology Department, 18761 North Frederick Avenue, Suite A, Gaithersburg, MD 20879, USA.
| |
Collapse
|