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Clinical and molecular aspects of HIV-associated lipodystrophyMallon, Patrick William Gerard, School of Medicine, UNSW January 2006 (has links)
HIV-associated lipodystrophy (HIVLD) syndrome is a condition comprising abnormalities in distribution of body fat and metabolism of lipids and glucose that arises in HIV-infected patients on long-term antiretroviral therapy. This thesis describes clinical research into aspects of the natural history and treatment of HIVLD, as well as molecular research into its pathogenesis centred on subcutaneous adipose tissue. Results demonstrate HIVLD to be a treatment-induced syndrome characterised by initial gains in body fat followed by selective, progressive loss of limb fat. Exposure to thymidineanalogue nucleoside reverse transcriptase inhibitors (tNRTI) induces lipoatrophy through mitochondrial dysfunction of which inhibition of mitochondrial RNA expression, rather than mitochondrial DNA depletion, is an early feature. Mitochondrial dysfunction is associated with decreases in expression of peroxisome proliferatoractivated receptor gamma (PPAR??), an adipocyte transcription factor, which helps explain how tNRTI exposure leads to the loss of adipocyte function. Once established, lipoatrophy is characterised by mitochondrial DNA depletion, although this depletion occurs throughout the mitochondrial genome, suggesting an underlying cause other than inhibition of DNA polymerase gamma. HIVLD is a difficult syndrome to treat. Lipoatrophy is resistant to treatment with rosiglitazone, an agonist of PPAR??, which is ineffective in the setting of ongoing tNRTI therapy and mitochondrial dysfunction. Dyslipidaemia is also difficult to treat as use of pravastatin in the setting of ongoing exposure to protease inhibitors results in only modest declines in fasting cholesterol concentrations. Gains in central fat, such as that seen in patients with buffalo hump, are associated with insulin resistance and diabetes, but only occur in a relatively small percentage of treated patients, suggesting a role for genetic factors in its development. Use of strategies such as avoidance of tNRTI in firstline ART, genetic screening to identify those at risk of toxicities and targeted selection of interventions in subgroups of affected patients, may help prevent this syndrome occurring and better treat those patients in which it has already occurred.
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Design, synthesis and screening of novel PCU-peptide/peptoid derived HIV protease inhibitors.Makatini, Maya Mellisa. January 2011 (has links)
The AIDS epidemic in Africa has reached dramatic proportions. Of the 42 million people infected with
HIV worldwide, 30 million are in Africa. Current available therapies have begun to transform this fatal
disease into a chronic condition but there are still major obstacles that have resulted in a great demand for
new and better drugs. The aim of this study was to synthesize novel and effective HIV protease
inhibitors.
This work describes the first account of pentacycloundecane (PCU)-peptide and peptoid based protease
inhibitors. These inhibitors are proposed to bind the wild type C-South African HIV protease (C-SA)
catalytic site via the norstatine or dihydroxylethelene type functional group of the PCU. The desired
compounds were synthesized by the coupling of the peptides and peptoids to the PCU cage which
resulted in a series of promising and structurally diverse HIV-1 protease inhibitors. The inhibitors were
characterized by Nuclear Magnetic Resonance (NMR) and evaluated against the wild type C-SA enzyme
for its ability to inhibit 50 % of the enzyme’s activity (IC50). Two of the compounds reported herein,
inhibited the enzyme activity at concentrations less than 80 nM.
NMR investigations indicated that the activity was related to the chirality of the PCU moiety and its
ability to induce conformations of the coupled peptide side chain. Employing the new Efficient Adiabatic
Symmetrized Rotating Overhauser Effect Spectroscopy (EASY-ROESY) technique enabled us to obtain
vital information about the 3D structure of these small linear peptides and peptoids in solution. This
technique is the first example describing the successful through space correlations of such small peptides.
Furthermore, docking and a combined quantum mechanics/molecular mechanics (QM/MM) molecular
dynamics MD simulation at the AM1 semi empirical level mirrored the observed NMR results and the
experimental IC50 activity profile of the considered inhibitors. The combination of these experimental
and theoretical methods provided a powerful insight into the interaction mode of these cage peptide and
peptoid inhibitors with the enzyme. / Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2011.
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HIV-1 specific T-Cell responses in chronic HIV infected children during continuous treatment and structured treatment interruptions (STI).Reddy, Shabashini. January 2010 (has links)
BACKGROUND Sub-Saharan Africa has the highest number of HIV-infected individuals and limited treatment programs. The use of Highly Active Antiretroviral Therapy (HAART) has resulted in a considerable decrease in morbidity and mortality among HIV-infected individuals. Long-term use of HAART has several limitations relating to cost, drug toxicity and adherence. Structured Treatment Interruption (STI) has been proposed as a therapeutic approach which limits the exposure to continuous HAART, but retains the benefits thereof. The role of HIV-specific Tcell responses in the control of viraemia has not been well studied in children and it is not clear when these responses become detectable or whether they are associated with improved viral control. Furthermore, antiretroviral drug resistance is well documented in adults infected with HIV-1 clade B virus but comparable information is lacking for chronic paediatric clade C virus infection. This pilot study focused on a chronic HIV-infected paediatric cohort from Durban, South Africa, to assess the immunologic and virologic responses in perinatal HIVinfected children undergoing STI. METHODS Thirty chronic HIV-infected treatment naïve children were enrolled and randomised into either the treatment interruption or continuous treatment group. Longitudinal measurements of viral loads and CD4 percentages were done at scheduled intervals. Peripheral blood mononuclear cells (PBMCs) were screened for cytotoxic T-lymphocyte (CTL) gamma interferon (IFN-?) enzyme-linked immunospot (ELISpot) assay responses using 410 peptides which spanned the entire HIV-1 clade C proteome. Intracellular cytokine staining (ICS) was done to distinguish between IFN-? Gag-specific T-helper and cytotoxic T cell responses. Pre-HAART drug resistance mutations testing and HLA typing were done for all children. RESULTS There was a significant increase in the median CD4 percentage after HAART was introduced. Six children randomized to the STI arm did not undergo treatment interruption because their viral loads remained detectable at the time of scheduled interruption. Most HIV proteins were targeted in this paediatric cohort. Gag was the most frequently targeted HIV-1 protein (93.1%). In both treatment groups, there were broadening of T-cell responses, however, the magnitude of T-cell responses decreased over time on HAART. Drug-resistant mutations were detectable in 4/29 children before initiation of HAART. CONCLUSION In this pilot study, the HIV-1-specific CD8+ and CD4+ T-cell responses were detected before and during HAART. Although the treatment interruption period was short, there were no adverse outcomes in either the continuous or treatment interruption groups in terms of death or other clinical outcomes. This study suggests that it is important to continue to explore alternative treatment strategies in order to reduce cost and toxicity as well as to enhance adherence. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, Durban, 2010.
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Anti-retroviral activity of lavendamycin analogsWang, Aiqin January 1996 (has links)
Lavendamycin, an aminoquinolinedione antibiotic is similar to streptonigrin, an antibiotic with known antiretroviral activity. Their applicability as drugs is limited due to their high toxicity to mammalian cells. A series of novel analogs of lavendamycin has been recently synthesized. In initial screening, three of the analogs showed significant inhibitory activity toward the reverse transcriptase (RT) of the avian myeloblastosis virus (AMV) and exhibited little or no animal toxicity and relatively low cellular cytotoxicity.In this study, we determined the anti-retroviral activity of nine analogs by assessing their anti-reverse transcriptase(anti-RT) activity in comparison to streptonigrin. Using both the human immunodeficiency virus (HIV) and AMV reverse transcriptase in vitro we found that the analogs exhibited significant anti-RT activity. The inhibitory activity of the analogs was dose dependent, and they had different effects on the two enzymes. At 30 µM seven of the analogs inhibited HIV-RT activity by 50% or more. At this concentration, two of the analogs were significantly more effective than streptonigrin. AMV-RT was more sensitive toward both streptonigrin and several of the analogs than was HIV-RT. Furthermore, combination of azidothymidine (AZT)-triphosphate (TP) and several of analogs showed synergistic inhibitory effects at low doses. / Department of Biology
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Clinical and molecular aspects of HIV-associated lipodystrophyMallon, Patrick William Gerard, School of Medicine, UNSW January 2006 (has links)
HIV-associated lipodystrophy (HIVLD) syndrome is a condition comprising abnormalities in distribution of body fat and metabolism of lipids and glucose that arises in HIV-infected patients on long-term antiretroviral therapy. This thesis describes clinical research into aspects of the natural history and treatment of HIVLD, as well as molecular research into its pathogenesis centred on subcutaneous adipose tissue. Results demonstrate HIVLD to be a treatment-induced syndrome characterised by initial gains in body fat followed by selective, progressive loss of limb fat. Exposure to thymidineanalogue nucleoside reverse transcriptase inhibitors (tNRTI) induces lipoatrophy through mitochondrial dysfunction of which inhibition of mitochondrial RNA expression, rather than mitochondrial DNA depletion, is an early feature. Mitochondrial dysfunction is associated with decreases in expression of peroxisome proliferatoractivated receptor gamma (PPAR??), an adipocyte transcription factor, which helps explain how tNRTI exposure leads to the loss of adipocyte function. Once established, lipoatrophy is characterised by mitochondrial DNA depletion, although this depletion occurs throughout the mitochondrial genome, suggesting an underlying cause other than inhibition of DNA polymerase gamma. HIVLD is a difficult syndrome to treat. Lipoatrophy is resistant to treatment with rosiglitazone, an agonist of PPAR??, which is ineffective in the setting of ongoing tNRTI therapy and mitochondrial dysfunction. Dyslipidaemia is also difficult to treat as use of pravastatin in the setting of ongoing exposure to protease inhibitors results in only modest declines in fasting cholesterol concentrations. Gains in central fat, such as that seen in patients with buffalo hump, are associated with insulin resistance and diabetes, but only occur in a relatively small percentage of treated patients, suggesting a role for genetic factors in its development. Use of strategies such as avoidance of tNRTI in firstline ART, genetic screening to identify those at risk of toxicities and targeted selection of interventions in subgroups of affected patients, may help prevent this syndrome occurring and better treat those patients in which it has already occurred.
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Transmitted and acquired HIV drug resistence in VietnamVu, Phuong Thao January 2015 (has links)
No description available.
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Synthesis of novel coumarin derivatives as potential inhibitors of HIV-1 proteaseRose, Nathan Rolf 01 July 2013 (has links)
This research has focused on the development of novel coumann derivatives containing peptide-like side chains as potential HIV-1 protease inhibitors. The reaction of various salicylaldehyde derivatives with tert-butyl acrylate In the presence of 1,4- diazabicyclo[2.2.2]octane (DABCO) has afforded a series of Baylis-Hillman adducts in moderate yield. Cyclisation of the adducts in the presence of HCI afforded the corresponding 3-(chloromethyl)coumarin derivatives, which have been reacted with various amine hydrochlorides in the presence of Proton Sponge® to afford a series of novel 3- (aminomethyl)coumarin derivatives, which were fully characterised by NMR and HRMS methods. Various approaches to the introduction of hydroxyl or amino groups at the C-4 position of coumarin and the 3-(chloromethyl)coumarin derivatives have been explored; these have included dihydroxylation of the coumarin double bond, and the synthesis of 4- benzylaminocoumarin derivatives as potential intermediates. The Vilsmeier-Haack and Mannich reactions have also been investigated as possible methods of introducing the desired peptide-like functionality. Computer modelling of selected structures has indicated that some of the novel 3- (aminomethyl)coumarin derivatives may exhibit activity as inhibitors of HIV-1 protease. The planned enzyme inhibition assays were unfortunately precluded by the aqueous insolubility of the selected compounds. Three ¹³C NMR chemical shift algorithms, viz., Modgraph Neural Network, Modgraph HOSE and Chern Window, have been applied to selected compounds prepared in this study. The Modgraph Neural Network algorithm was found, in all cases, to provide the most accurate correlations with the experimentally-determined chemical shifts. / KMBT_363 / Adobe Acrobat 9.54 Paper Capture Plug-in
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Pharmacokinetic herb-drug interaction study of selected traditional medicines used as complementary and alternative medicine (CAM) for HIV/AIDSAwortwe, Charles 03 1900 (has links)
Thesis (DMed)--Stellenbosch University, 2015 / ENGLISH ABSTRACT: Introduction
The increasing intake of traditional medicines among HIV/AIDS patients in sub-Saharan Africa needs urgent consideration by clinicians and other healthcare providers since the safety of such medications are unknown. The pharmacokinetic parameters - Absorption, Distribution, Metabolism and Elimination (ADME) play important role in the safety evaluation of drugs, thus implicating drug metabolizing enzymes and transporters as critical indicators for herb-drug interactions. The objective of this study was to evaluate the risk potential of seven herbal medicines commonly consumed by HIV/AIDS patients for drug interactions applying in vitro models. In this study, inhibition and induction effects of the herbal medicines on cytochrome P450s (CYPs) 1A2, 2C9, 2C19, 2D6 and 3A4 as well as P-glycoprotein (P-gp) were investigated.
Methods
Herbal medicines – Lessertia frutescens, Hypoxis hemerocallidea, Kalanchoe integra and Taraxacum officinale were sourced from Medico Herbs, South Africa were identified by experts from Compton Herbarium, South African National Biodiversity Institute, Cape Town. Moringa oleifera, Echinacea purpurea and Kalanchoe crenata were obtained from the repository of the National Centre for Natural Product Research (NCNPR), University of Mississippi, USA. Reversible inhibitory effect of aqueous and methanol herbal extracts were evaluated in recombinant CYPs applying the fluorescent metabolites at specified excitation/emission wavelengths; CYP1A2 (3-cyano-7-hydroxycoumarin (CHC); 405/460 nm), CYP2C9, CYP2C19 and CYP3A4 (7-hydroxy-4-(trifluoromethyl)-coumarin (HFC); 405/535 nm) and CYP2D6 (7-hydroxy-4-(aminomethyl)-coumarin (HAMC); 390/460 nm). Comparative studies in human liver microsomes (HLM) and recombinant CYPs were conducted to investigate the inhibitory effect of methanol herbal extracts and fractions on 6β testosterone hydroxylation activity. Time dependent inhibitory (TDI) effect of the herbal extracts were evaluated applying the IC50 shift fold, normalized ratio and the NADPH-, time- and concentration-dependent approaches. Influence of herbal extracts on metabolic clearance of testosterone was assessed in both HLM and human hepatocytes. The effects of each herbal extract on expression of CYP1A2, CYP3A4 and MDR1 genes were evaluated in activated human pregnane X receptor (PXR) co-transfected HepG2 cells. Finally, the inhibitory effect of herbal extracts on P-gp was assessed using the calcein-acetoxymethyl ester (calcein-AM) uptake and the digoxin radiolabelled substrates in MDCKII-MDRI cells.
Results
The aqueous extracts of Moringa oleifera, Kalanchoe integra, Kalanchoe crenata, Echinacea purpurea and Lessertia frutescens demonstrated high risk of in vivo inhibition on CYPs 3A4 and 1A2 with Cmax/Ki >1.0. Methanol extracts of these herbal medicines also indicated potential risk of reversible drug interaction. The methanol extracts of M. oleifera, K. crenata and L. frutescens showed strong TDI effect on CYP3A4 with IC50 shift fold >1.5 and normalised ratio <0.7. Moringa oleifera intermediately reduced intrinsic clearance of testosterone in human hepatocytes (2 ≤ AUC ratio ≤ 5) when scaled up to humans. Methanol extracts of Echinacea purpurea up-regulated the expression of CYP1A2, CYP3A4 and MDR1 genes in activated PXR. Kalanchoe crenata and Echinacea purpurea indicated strong inhibition on P-gp by reducing transport of digoxin across hMDR1-MDCKII cell monolayer from basolateral to apical with IC50 values of 18.24 ± 2.52 μg/mL and 24.47 ± 4.97 μg/mL, respectively.
Conclusion
The herbal medicines especially M. oleifera, K. integra and E. purpurea have the potential to cause herb-drug interaction in vivo if sufficient hepatic concentration is achieved in humans. / AFRIKAANSE OPSOMMING: Inleiding
Die verhoogde inname van tradisionele medisynes onder MIV/VIGS-pasiënte in sub-Sahara-Afrika verg dringend oorweging deur klinici en ander gesondheidsorgverskaffers, aangesien die veiligheid van sodanige medikasies onbekend is. Die farmakokinetiese parameters – Absorpsie, Distribusie, Metabolisme en Eliminasie (ADME) – speel ’n belangrike rol by die veiligheidsevaluering van geneesmiddels, en impliseer gevolglik geneesmiddel-metaboliserende ensieme en vervoerders as kritiese indikators vir krui-geneesmiddel-interaksies (HDI). Die oogmerk van hierdie studie is om die risikopotensiaal van sewe kruiemedisynes wat algemeen deur MIV/VIGS-pasiënte geneem word, vir geneesmiddel-interaksies te evalueer deur in vitro-modelle te gebruik. In hierdie studie is die inhiberings- en induseringsuitwerkings van die kruiemedisynes op sitochroom P450’s (verkort na CYP’s) 1A2, 2C9, 2C19, 2D6 en 3A4, sowel as P-glikoproteïen (P-gp), ondersoek.
Metodes
Kruiemedisynes – Lessertia frutescens, Hypoxis hemerocallidea, Kalanchoe integra en Taraxacum officinale – is van Medico Herbs, Suid-Afrika, bekom en deur kundiges van die Compton-herbarium, by die Suid-Afrikaanse Nasionale Biodiversiteitsinstituut, Kaapstad, geïdentifiseer. Moringa oleifera, Echinacea purpurea en Kalanchoe crenata is van die bewaarplek van die Nasionale Sentrum vir Natuurlike Produknavorsing (NCNPR) aan die Universiteit van Mississippi in die VSA verkry. Die omkeerbare inhiberende uitwerking van kruie-ekstrakte in water en metanol is in rekombinante CYP’s geëvalueer deur die gebruik van die fluoresserende metaboliete op gespesifiseerde opwekkings-/emissiegolflengtes; CYP1A2 (3-siaan-7-hidroksikumarien (CHC); 405/460 nm), CYP2C9, CYP2C19 en CYP3A4 (7-hidroksi-4-(trifluoormetiel)-kumarien (HFC); 405/535 nm) en CYP2D6 (7-hidroksi-4-(aminometiel)-kumarien (HAMC); 390/460 nm). Vergelykende studies van menslikelewermikrosome (HLM) en rekombinante CYP’s is uitgevoer om die inhiberende uitwerking van metanolkruie-ekstrakte en -fraksies op 6β-testosteroonhidroksileringsaktiwiteit te ondersoek. Die tydafhanklike inhiberende uitwerking (TDI) van die kruie-ekstrakte is geëvalueer deur gebruikmaking van die IC50-verskuiwingsvou-, die genormaliseerdeverhoudings- en die NADPH-, tyd- en konsentrasieafhanklike benaderings. Die invloed van kruie-ekstrakte op metaboliese testosteroonverheldering is in beide HLM en menslike hepatosiete geëvalueer. Die uitwerkings van elke kruie-ekstrak op die uitdrukking van CYP1A2-, CYP3A4- en MDR1-gene is in geaktiveerde menslike pregnaan-X-reseptor(PXR)-, ko-getransfekteerde HepG2-selle geëvalueer. Laastens is die inhiberende uitwerking van kruie-ekstrakte op P-gp geëvalueer, met gebruikmaking van die kalsien-asetoksimetiel-ester (kalsien-AM)-opname en die digoksien- radiogemerkte substrate in MDCKII-MDRI-selle.
Resultate
Die ekstrakte in water van M. oleifera, K. integra, K. crenata, E. purpurea en L. frutescens het ’n hoë risiko van in vivo-inhibering op CYP’s 3A4 en 1A2 met Cmaks/Ki >1.0 getoon. Ekstrakte van hierdie kruiemedisynes in metanol het verder potensiële risiko van omkeerbare geneesmiddelinteraksie getoon. Die ekstrakte van M. oleifera, K. crenata en L. frutescens in metanol het sterk TDI-uitwerking op CYP3A4 met IC50-verskuiwingsvou >1.5 en genormaliseerde verhouding <0.7 getoon. M. oleifera het intermediêre vermindering van intrinsieke testosteroonverheldering in menslike hepatosiete (2 ≤ AUC verhouding ≤ 5) tot gevolg wanneer die skaal na mense verhoog word. Ekstrakte van E. purpurea in metanol het die uitdrukking van CYP1A2-, CYP3A4- en MDR1-gene in geaktiveerde PXR opgereguleer. K. crenata en E. purpurea het sterk inhibering van P-gp getoon deur die vervoer van digoksien deur die hMDR1-MDCKII-selmonolaag van basolateraal tot apikaal met IC50-waardes van onderskeidelik 18.24 ± 2.52 μg/mL en 24.47 ± 4.97 μg/mL te verminder.
Gevolgtrekking
Kruiemedisynes, veral M. oleifera, K. integra en E. purpurea, het die potensiaal om HDI in vivo te veroorsaak indien voldoende hepatiese konsentrasie by mense bereik word.
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Drug-drug interactions between antiretrovirals and fluconazole in HIV-infected patientsFouche, Desire 03 1900 (has links)
Thesis (MScMedSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: Background: HIV-positive patients have a significantly weakened immune system which
makes them highly susceptible for opportunistic infections, requiring additional treatment.
Cryptococcal meningitis and oropharyngeal candidiasis are treated with oral fluconazole. A
great potential for drug-drug interactions (DDIs) between fluconazole and antiretrovirals
(ARVs), efavirenz, nevirapine, and lopinavir/ritonavir, exists due to interference in common
metabolic pathways. The outcome may result in the development of adverse drug reactions
or drug resistance and treatment failure.
Aim: The primary aim of this thesis was to evaluate the effect of fluconazole on the
pharmacokinetics of efavirenz, nevirapine and lopinavir/ritonavir in HIV-infected patients
diagnosed with cryptococcal meningitis or oropharyngeal candidiasis.
Methods: A prospective study was conducted in 80 HIV-positive, treatment experienced
adults (≥18 years old) treated in three different outpatient clinics in the Western Cape region.
Patients were subdivided according to ARV regimen and the use of fluconazole. A sparse
sampling design was used and corresponding ARV serum concentrations were determined by
established HPLC and GC methods. Fluconazole serum concentrations were determined by a
newly developed HPLC method. Patient characteristics, concomitant medications, clinical
test data and ARV serum concentrations were included in a NONMEM generated, onecompartment,
open pharmacometric model with first order elimination to detect any drugdrug
interactions between fluconazole and the studied ARVs. The secondary outcome was to
establish which patient characteristics influence ARV pharmacokinetics.
Results: From 80 outpatients, a total of 276 ARV serum samples (137 efavirenz, 67
nevirapine and 72 lopinavir) were collected for pharmacokinetic evaluation. Efavirenz
clearance was correlated with race and concomitant use of rifampicin. No significant
covariates were established in the nevirapine model. In the lopinavir model, concomitant use
of clotrimazole and the antituberculosis combination isoniazid, pyrazinamide and rifampicin
were identified as significant covariates.
Discussion: No significant effects of fluconazole on the pharmacokinetics of any of the
studied ARVs were observed. Varying efavirenz plasma concentrations in different ethnic
populations may be due to differences in gene expression particularly CYP2B6. Coloured patients had significantly lower efavirenz serum concentrations (56.8% decrease in
clearance), which has not been previously described in the South African context. Although
gender was not a significant covariate in the nevirapine model, female patients tended to have
higher nevirapine serum concentrations. TB treatment in all patients receiving lopinavir
consisted of a combination of isoniazid, pyrazinamide and rifampicin, each with different
effects on CYP isoenzymes. The exact contributing factor of each drug in the ultimate
decrease in lopinavir clearance (46.4%) can therefore not be established.
Conclusions: Given the limitations of the sample size in the present study, no statistical
significant effect of fluconazole on the pharmacokinetics of the investigated ARVs could be
demonstrated. A retrospective analysis of the data showed various co-factors that influence
the pharmacokinetics of the investigated ARVs. This data needs to be confirmed in a
prospective study as the identified covariates are appropriate in the management of HIVinfected
patients in the South African context. / AFRIKAANSE OPSOMMING: Agtergrond: HIV-positief pasiënte het ‘n aansienlike verswakte immuunstelsel, wat hul
hoogs vatbaar tot opportunistiese infeksies maak, en dus, addisionele behandeling benodig.
Cryptococcal meningitis en orofaringeale kandidiase word met orale flukonasool behandel.
As gevolg van middeling in algemene metaboliese paaie is daar ‘n groot moontlikheid van
middel-middel interaksies tussen flukonasool en die antiretrovirale (ARV) middels,
efavirenz, nevirapine, en lopinavir/ritonavir. Die uitkomste hiervan mag tot die ontwikkeling
van nadelige middel-middel interaksies of middelweerstandigheid en mislukte behandeling
lei.
Doel: Die primêre doel van hierdie tesis was om die effek van flukonasool op die
farmakokinetika van efavirenz, nevirapine en lopinavir/ritonavir in HIV geïnfekteerde
pasiënte met gediagnoseerde cryptococcal meningitis en orofaringeale kandidiase te evalueer.
Metodes: Die studie was met 80 HIV-positief, behandeling-ervare volwassenes (≥18 jaar)
onderneem. Voorafgenoemde was in drie verskillende buitepasiëntklinieke in die Wes-Kaap
behandel. Pasiënte was volgens ARV regimen en die gebruik van flukonasool, of dan nie,
verder verdeel. ‘n Beperkte steekproef ontwerp was gebruik, en ooreenstemmende ARV
serum konsentrasies is deurgevestigde HPLC en GC metodes vasgestel. Flukonasool serum
konsentrasies was deur ‘n nuutontwikkelde HPLC metode vasgestel. Pasiëntkenmerke,
gepaardgaande medikasie, kliniesetoets data en ARV serum konsentrasies was by ‘n
NONMEM genereerde, een-kompartement, oop farmakometriese model met eerste orde
eliminasie ingesluit om enige middel interaksies tussen flukonasool en die bestudeerde ARVs
op te tel. Die sekondêre uitkomste was om vas te stel watter pasiënt kenmerke ARV
farmakokinetika beïnvloed.
Resultate:Uit 80 buitepasïente was ‘n totaal van 276 ARV serum monsters (137 efavirenz,
67 nevirapine en 72 lopinavir) vir farmakokinetiese evaluasie gekollekteer. Efavirenz
opruiming was met ras gekorreleer asook gepaardgaande gebruik van rifampisien. Geen
betekenisvolle ko-variante was in die nevirapine model vasgestel nie. In die lopinavir model
het die gepaardgaande gebruik van clotrimazole en die anti-tuberkulose kombinasie
isoniazied, pyrazinamied en rifampisien, lopinavir opruiming verminder.
Bespreking: In hierdie studie is geen betekenisvolle effekte van flukanosool op die
farmakokinetika van enige van die bestudeerde ARVs waargeneem nie. Afwisselende
efavirenz plasma konsentrasies in verskillende etniese populasies mag aan verskille in
geenuitdrukking, veral CYP2B6, toegeskryf word. Kleurling pasïente het betekenisvolle
verlaagde efavirenz serum konsentrasies getoon (56.8% verlaging in opruiming). Hierdie
bevinding is nog nooit voorheen in die Suid-Afrikaanse konteks beskryf nie. Alhoewel geslag
nie ‘n beduidende ko-variant in die nevirapine model was nie, het vroulike pasïente geneig
om hoer nevirapine serum konsentrasies te hê. TB behandeling, in alle pasïente wat lopinavir
ontvang het, het uit die volgende kombinasie bestaan: isoniazied, pyrazinamied en
rifampisien, elk met hul eie effekte op CYP isoensieme. Die presiese bydra van elke middel
in die uiteindelike verlaging (46.4%) in lopinavir opruiming kan dus nie vasgestel word nie.
Gevolgtrekking: Gegewe die beperkings van die steekproef in die huidige studie, kon geen
statistiese beduidende effek van flukonazool op die farmakokinetika van die betrokke ARVs
gedemonstreer word nie. ‘n Retrospektiewe analise van die data het gewys dat verskeidene
ko-faktore die farmakokinetika van die betrokke ARVs beïnvloed. Hierdie data moet in ‘n
prospektiewe studie bevestig word omdat die geidentifiseerde covariates die bestuur van
MIV-positiewe pasiente in die Suid-Afrikaanse konteks te verbeter.
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Counterfeiting of HIV/AIDS medicines : implications for global epidemic : recommendations for workplace programsNorris, Gerard Benedict 04 1900 (has links)
Thesis (MPhil)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: multiple therapeutic categories of medicines
have been increasingly targeted for counterfeiting.
According to Van Niekerk [Van Niekerk, Anton. (2001). Moral and social complexities
of AIDS in Africa. University of Stellenbosch], “it is commonplace to identify and
bewail a plethora of problems in the developing world generally, and in Africa in
particular. Poverty, illiteracy, famine, political instability, natural disasters, and
many more misfortunes dominate the history of this part of the world over the past
50 years. It was therefore adding uncalled (undeserved?) insult to already
overwhelming injury when HIV/AIDS visibly struck the world since mid-1980. In
spite of all the other calamities that Africa has to deal with, it nevertheless is no
exaggeration to claim that HIV/AIDS nowadays constitutes the most serious health
and social crisis and challenge that has ever befallen the continent”. Similar patterns
involving HIV/AIDS are now emerging on other continents.
One objective of this recent research study was to explore possible relationships between
the growing scourges of the worldwide counterfeiting of medicines and parallels with the
expanding global HIV/AIDS pandemic - as well as to examine potential relationships and
risks associated with other diseases that have been observed to have ‘special associations’
with HIV and AIDS [e.g. sexually transmitted infections (STI’s), Tuberculosis (TB) and
Malaria] - and possible impact on the “World of Work”. A second and important
objective was to develop Recommendations for Workplace Programs. The information
gathered has also been used to propose future studies regarding HIV/AIDS and
counterfeiting.
In the developing world, antibiotics and anti-parasitic medicines are included among the
counterfeiters’ favorite targets. Strong parallels exist between locations where
counterfeiting of medicines is taking place/product being distributed/sold and where
HIV/AIDS is most prevalent and/or where the epidemic is expanding progressively.
Counterfeiting of medicines used for treating HIV/AIDS raises the possibility of
additional future complications developing in managing other global diseases such as
Malaria and Tuberculosis, not to mention exacerbating the potential for developing
resistance and encouraging mutation of the HI virus itself. It is also noteworthy that
certain medical devices have also been found to be counterfeit.
Global demographics and with particular reference to projected growth rates of
populations of the developing world are of specific relevance to this subject of anticounterfeiting
and medicines used for the treatment of HIV and AIDS. Indeed, next
generations of humanity appear to be at unnecessary risk of being caught up in a
confluence of forces whereby the practice of the counterfeiting of medicines could result
in significant complications and unforeseen consequences regarding management of the
global HIV/AIDS crisis. Following the research, recommendations for workplace
programs were developed. The research study concludes with a comprehensive set of
references. / AFRIKAANSE OPSOMMING: Die problamatiek aangaande die vervalsing (namaak) van medisyne word nou wereldwyd
ervaar en het ‘n impak op beide die geindustrialiseerde en die ontwikkelende wereld.
Menige medisyne in terapeutiese kategoriee is tot op hede as vervals geidentifeseer, met
die direkte resultaat dat hulle ‘n minemale of geen terapeutiese uitwerking het nie. Wat
nog erger is, is dat hierdie middels uiters gevaarlik is om te gebruik en selfs
lewensgevaarlik kan wees. Dit is van groot betekenis dat ook medisyne wat bestem is om
persone met HIV/VIGS te behandel, as vervals aangetoon is – en soedoende tot nog toe
onbekende gevolge vir pasiente, die werkomgewing en ongekende risiko’s vir wereldwye
gesondheidsorg en internasionale veiligheid en sekuriteit inhou. In hierdie studie word
die onderwerp in taamlike besonderhede bestudeer en daar word afgesluit met
aanbevelings oor programme in die werkplek wat ontwerp is om sorg en ondersteuning te
bied aan werkers met HIV/VIGS. Verdere studie word ook aanbeveel om die tergende
probleme wat volg op die vervalsing van medisyne in die behandling van persone met
HIV/VIGS, en die implikasies hiervan, die hoof te bide.
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