Background: Efavirenz is associated with transient neuropsychiatric manifestations but the impact on neurocognition is unknown. Genetically determined black South Africans who are slow metabolizers of efavirenz may be at risk of toxicity. This study describes neuropsychiatric and neurocognitive manifestations of South African children with suspected efavirenz neurotoxicity. Method: This retrospective study describes clinical features of 12 children with suspected efavirenz neurotoxicity (2008 – 2014). Results: Twelve children were referred (aged 3 years 4 months to 12 years, mean 7 years 8 months; 8 indigenous African (black) and 4 mixed ancestry). Six had acute neuropsychiatric manifestations after 2-8 weeks (mean 5 weeks) on efavirenz including drowsiness, seizures, sleep disturbances, behavioural changes, ataxia and slurred speech. Symptoms resolved over a few weeks in four. Two black children were phenotypically slow metabolizers with high plasma efavirenz concentrations above normal range resulting in discontinuation of efavirenz. Nine children had neurocognitive concerns potentially exacerbated by long-term efavirenz (6-72 months therapy; mean 31 months), and showed poor performance in all neurocognitive domains. Conclusion: Efavirenz causes transient neuropsychiatric adverse effects and may contribute to poor longterm neurocognitive outcomes in HIV-infected children. Genetically slow metabolizers are at risk of neurotoxicity. Prospective studies comparing efavirenz-treated and efavirenz-naïve children are needed.

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-11T19:25:05Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) SALVANA PRISCYLLA MANSO COSTA_PPGIT_CCB_2016.pdf: 8213740 bytes, checksum: c0b4ea6211a86ddfa6dab45ce846ee02 (MD5) / Made available in DSpace on 2016-08-11T19:25:05Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) SALVANA PRISCYLLA MANSO COSTA_PPGIT_CCB_2016.pdf: 8213740 bytes, checksum: c0b4ea6211a86ddfa6dab45ce846ee02 (MD5) Previous issue date: 2016-02-26 / CAPES / efavirenz (EFZ) é considerado uma das drogas anti-HIV mais utilizadas, porém é classificado como fármaco de classe II (baixa solubilidade, alta permeabilidade), segundo o sistema de classificação biofarmacêutica, apresentando problemas de absorção no trato gastrointestinal e, consequentemente, biodisponibilidade inadequada para sua ação terapêutica. Assim, este trabalho objetivou desenvolver sistemas microparticulados com polímeros inovadores afim de contornar estes entraves através da técnica de dispersões sólidas (DS). Para o desenvolvimento de DS com o EFZ, realizaram-se, inicialmente, estudos teóricos e práticos que permitiram selecionar o PVP-K30, o PVPVA 64 SOLUPLUS e HPMCAS como carreadores da formulação. As DS com esses polímeros foram preparadas pelo método do solvente. A análise de Difração de raios-X (DRX) mostrou que os polímeros são capazes de manter o EFZ em sua forma amorfa até uma concentração de 80% fármaco. Através dos estudos de dissolução in vitro, verificou-se que o sistema DS PVPVA 64 – EFZ 10% seria o mais promissor, uma vez que o mesmo foi capaz de aumentar em até seis vezes a AUC quando comparado ao fármaco isolado, além de manter os níveis de supersaturação por um período de 120 minutos. Os sistemas DS PVP-K30 – EFZ 10% e DS HPMCAS – EFZ 10% obtiveram bons resultado no estudo de dissolução in vitro e, assim, também foram selecionados. O método para quantificação do EFZ otimizado foi co-validado de acordo com o preconizado pela RE nº 899/03 da ANVISA e pelo ICH e demonstrou-se: linear, preciso e exato para os parâmetros avaliados. A caracterização físico-química das DS com PVP K-30 e PVPVA 64 através de técnicas calorimétricas, microscópicas e espectrofotométricas evidenciou a conversão do EFZ para o seu estado amorfo e verificou que o PVPVA 64 interage de maneira mais efetiva quando comparado ao PVP-K30. No entanto com base nos resultados preliminares do estudo de estabilidade acelerada, pode-se observar que tanto o PVP K-30 quanto o PVPVA 64 foram capazes de inibir a cristalização do fármaco, ao final de três meses de estudo. O comportamento e a estabilidade térmica do EFZ e da DS PVPVA 64 – EFZ 10% foram investigados por TG, DSC, DSC fotovisual e pirolisador acoplado a CG/MS. Foram observadas diferenças entre as curvas TG do fármaco puro e aquela do produto farmacêutico, devido à presença do polímero. Bem como, pôde-se observar que a DS promoveu uma proteção térmica ao EFZ, mostrando uma boa qualidade da formulação. Para os parâmetros cinéticos obtidos nas condições não-isotérmica e isotérmica, os valores da Ea para a DS foi igual a 101 e 132 kJ/mol, respectivamente, enquanto que os valores de Ea para o EFZ, segundo a literatura, estão entre 88 – 93 kJ/mol. A ordem da cinética de degradação da DS foi de primeira ordem, diferentemente do EFZ puro, que é de ordem zero. Além disso, através da equação de Arrhenius, pôde-se sugerir uma estabilidade de sete meses para a formulação. Os valores dos parâmetros cinéticos determinados pelos métodos isoconvencionais obtiveram valores de Ea na faixa de 88 – 95 kJ.mol-1, isto indica uma boa correlação entre os métodos aplicados. Uma vez que os valores de Ea variaram de acordo com o grau de conversão (a), pode-se verificar que o processo de degradação do EFZ se faz por mecanismos do tipo contração geométrica e nucleação. Dessa forma, a partir do estudo, obteve-se DS estáveis e adequadas para superar as limitações de solubilidade do efavirenz. / Efavirenz (EFV) is considered one of the most widely used anti-HIV drugs, but the drug is classified as class II (low solubility, high permeability) according to the biopharmaceutical classification system, having problems with absorption in the gastrointestinal tract and thereby inadequate bioavailability for its therapeutic action. Thus, this study aimed to overcome these barriers through the technique of solid dispersions (SD). For the development of SD with EFZ theoretical and practical studies were initially held which allowed the selection of PVP-K30, PVPVA 64, SOLUPLUS and HPMCAS as carriers of the formulation. The SD systems with these polymers were prepared by the solvent method. The analysis of X-ray diffraction (XRD) showed that the polymers are able to maintain EFZ in its amorphous form up to a concentration of 80% of drug. Through the in vitro dissolution studies, it was found that the SD system PVPVA 64 - EFV 10% would be the most promising since it was able to increase up to six times the AUC when compared to the drug alone, and to maintain the levels of supersaturation for a period of 120 minutes. The SD systems PVP- K30 - EFZ 10% and HPMCAS – EFZ 10% achieved good result during the in vitro dissolution study and, thus, it was also selected. The method for quantification of co-optimized EFZ was validated according to the criteria of the RE nº 899/03 of ANVISA and the ICH and demonstrated: linear, precise and accurate for all parameters evaluated.The physico-chemical characterization of the SD systems with PVP K-30 and PVPVA 64 through calorimetric, microscopic and spectroscopic techniques revealed the conversion of EFZ to its amorphous state and found that the PVPVA 64 interacts more effectively when compared to PVP- K30. However, based on preliminary results of the accelerated stability study, it can be seen that the PVP K-30 polymer was the most inhibitory effect crystallization of the drug after six months of study. The behavior and thermal stability of EFZ and SD PVPVA 64 - EFV 10% were investigated by TG, DSC, DSC photovisual and pyrolyzer coupled with GC/MS. Differences between the TG curves of the pure drug and the pharmaceutical product were observed due to the presence of the polymer. Also, it was observed that the SD promoted a thermal protection of EFZ, showing the good quality of the formulation. Regarding the kinetic parameters obtained for the non-isothermal and isothermal conditions, the activation energy (Ae) values of the SD were equal to 101 and 132 kJ/mol, respectively, while the Ae values for the EFV, according to literature, are between 88 - 93 kJ/mol. Besides that, a first-reaction order was found for the SD, unlike the one for the pure EFZ, which was a zero-reaction order. Furthermore, by the Arrhenius equation, it could be suggested that the formulation would remain stable for seven months. In conclusion, in this study, we obtained stable and adequate SD systems to overcome the solubility limitations of efavirenz.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-09-21T12:07:22Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Jeyzon Valeriano-Dissertacao-2016.pdf: 2220289 bytes, checksum: ac06db6f610b526f0d583eff5e7b11d0 (MD5) / Made available in DSpace on 2016-09-21T12:07:22Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Jeyzon Valeriano-Dissertacao-2016.pdf: 2220289 bytes, checksum: ac06db6f610b526f0d583eff5e7b11d0 (MD5) Previous issue date: 2016-03-09 / CAPES / CNPq / FACEPE / A Terapia Antirretroviral Altamente Ativa (HAART) foi uma revolução que mudou drasticamente a evolução da infecção pelo HIV, transformando uma doença fatal em uma doença crônica. Efavirenz é um antirretroviral muito eficaz, mundialmente prescrito, presente no tratamento de primeira linha HAART, mas que apresenta uma alta frequência de efeitos neuropsiquiátricos que afetam a adesão ao tratamento, prejudicam a saúde e a qualidade de vida dos pacientes. Neste sentido, este estudo visa identificar polimorfismos genéticos associados à ocorrência de efeitos neuropsiquiátricos relatados no tratamento com Efavirenz em doses padrão. Através da análise retrospectiva dos prontuários dos 162 pacientes HIV positivos que utilizavam Efavirenz, 82 (50,6%) apresentaram efeitos adversos neuropsiquiátricos relacionados, dentre os quais: tonturas, cefaleia, insônia e depressão se mostraram os mais frequentes. Foi demonstrado que o uso da Zidovudina combinado ao Efavirenz, ao invés de Tenofovir (HR: 2,7; p-valor: 0,04), e o sexo feminino (HR: 3,5; p-valor: 0,05) aumentam o risco de tonturas e depressão, respectivamente, ao longo do tempo. Dez sete genes (CYP2B6, ABCB1, ABCC1, ABCC2, ABCC10, NR1I 2p oeli mNoRr1fiIs3m) ofosr eamm analisados. Apenas o polimorfismo no gene ABCC10 (rs2125739), alelo C, foi associado à ocorrência de efeitos adversos neuropsiquiátricos no tratamento com Efavirenz (OR: 2,6; p-valor: 0,03). Análises por regressão logística ajustada para variáveis demográficas, clínicas e genéticas, esta última relacionada ao aumento nas concentrações plasmáticas do Efavirenz, mostraram que os genótipos CT ou CC no rs2125739 estavam ainda mais associados com um risco elevado (OR: 5,1; p-valor: 0,007). Os resultados poderão contribuir para minimizar os riscos de eofceotrivrêidnacdiae ,d eid eefnetiitfoicsa nndeou roppasciqieuniátetrsi cossu sncae ptetírvaepiisa ceo mau Exiflaiavnirdeon z,n am aensteconldhoa sudaa HAART combinada. / Highly Active Antiretroviral Therapy (HAART) was a revolution that changed the HIV dynamic infection, turning a fatal disease into a chronic one. Efavirenz is a very efficient globally prescribed antiretroviral, present in first line of HAART treatment, but which presents a high frequency of neuropsychiatric adverse effects that affect treatment adherence, damaging the patients’ health and their quality of life. Thus, this study aims to identify genetic polymorphism associated with the occurrence of neuropsychiatric adverse effects in HIV-positive patients submitted to Efavirenz therapy in standard oral doses. Through retrospective analysis of medical records of 162 of these patients, 82 (50,6%) had neuropsychiatric adverse effects related, such as: dizziness, headache, depression and insomnia. Survival analysis demonstrated that the combined use of Efavirenz with Zidovudine instead of Tenofovir increases the dizziness risk (HR: 2.7; p value: 0.04), as well as female sex increases the depression risk (HR: 3.5; p-value: 0.05), both polymorphisms in seven genes (CYP2B6, ABCB1, ABCC1, AB CoCve2r, tAimBeC. CT1e0n, NR1I2 and NR1I3) were genotyped. Only a polymorphism on ABCC10 gene (rs2125739) was associated (C allele) with the neuropsychiatric adverse effects occurrence in treatment with Efavirenz (OR 2.6; p value: 0.03). Logistic regression analysis, adjusted to demographic, clinical and genetic variables related to increased plasma concentrations of Efavirenz, showed that the CT or CC genotypes at rs2125739 were even more significantly associated to a higher risk of neuropsychiatric effects (OR 5.1; p -value: 0.007). The results may help to minimize the neuropsychiatric effects risk in therapy with Efavirenz maintaining its effectiveness by identifying susceptible patients and assisting in the choice of combin ed HAART.

Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-05-31T18:35:47Z No. of bitstreams: 2 Dissertação - Aroldo Vieira de Moraes Filho - 2013.pdf: 777889 bytes, checksum: ff3a609fe7af52fcc55701fe96a8d450 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-06-01T11:20:13Z (GMT) No. of bitstreams: 2 Dissertação - Aroldo Vieira de Moraes Filho - 2013.pdf: 777889 bytes, checksum: ff3a609fe7af52fcc55701fe96a8d450 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-01T11:20:14Z (GMT). No. of bitstreams: 2 Dissertação - Aroldo Vieira de Moraes Filho - 2013.pdf: 777889 bytes, checksum: ff3a609fe7af52fcc55701fe96a8d450 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-02-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The antiretroviral drugs appeared to prevent the multiplying HIV virus in the body, reducing its virulence, but not eliminate it from infected cells. These drugs increase the length and the quality of life of AIDS patients. In this context, Efavirenz (EFV) is non-nucleoside reverse transcriptase inhibitors. The Tenofovir Disoproxil Fumarate (TDF), oral prodrug of tenofovir, is analogue of adenosine 5 'monophosphate, belonging to the class of nucleotide reverse transcriptase inhibitors. These drugs act on the mechanisms of HIV replication by inhibiting the action of reverse transcriptase and thus preventing viral DNA synthesis. In order to assess the toxic and toxic-genetic potential of EFV and TDF, the present study used the Test for Detection of Somatic Mutation and Recombination (SMART) in Drosophila melanogaster. 3rd stage larvae originating from standard cross (ST) between males mwh and females flr³, were treated with solution of EFV and TDF and distilled water (negative control), for approximately 48 hours (chronic treatment) until they reach the pupal stage. These strains are carriers of specific gene markers, located on the left arm of chromosome 3, which allow you to monitor events related to mutation, mitotic recombination and chromosome aberrations. The statistical diagnosis was obtained by conditional binomial test. In this work, the results demonstrated that the EFV was toxic in high concentrations, but showed no induction of toxic genetic events. Inversely, the TDF showed no toxicity at the concentrations tested, but was showed induction of toxic genetic events at all concentrations, with a prevalence of recombinogenic events. Then, it is essential to analyze constantly the effects risk/benefit of isolated drugs and identify toxic and toxic genetic activity of each drug in order to ensure the quality of life for patients who use monotherapies and offers support for investigations with therapies that use combinations of antiretroviral drugs. / Os medicamentos antirretrovirais surgiram para impedir a multiplicação do vírus HIV no organismo, reduzindo a sua virulência, porém sem eliminá-lo das células infectadas. Estes medicamentos aumentaram o tempo e a qualidade de vida dos pacientes com AIDS. Dentro deste contexto, o Efavirenz (EFV) é inibidor da transcriptase reversa não-análogo de nucleosídeo. O Fumarato de Tenofovir Desoproxila (TDF), pró-fármaco oral de tenofovir, é análogo da adenosina 5`-monofosfato, pertencente à classe de inibidores da transcriptase reversa análogos de nucleotídeos. Estes fármacos atuam nos mecanismos de replicação do HIV, inibindo a ação da transcriptase reversa e, consequentemente, impedindo a síntese de DNA viral. Com o intuito de avaliar o potencial tóxico e tóxico genético do EFV e do TDF, utilizou-se o Teste para Detecção de Mutação e Recombinação Somática (SMART) em Drosophila melanogaster. Larvas de 3º estágio oriundas do Cruzamento Padrão (ST – standard cross) entre machos mwh e fêmeas flr³, foram tratadas com soluções de EFV e TDF, assim como com água destilada (controle negativo), por aproximadamente 48 h (tratamento crônico), isto é, até atingirem o estágio de pupa. Essas linhagens são portadoras de genes marcadores específicos, localizados no braço esquerdo do cromossomo 3, que permitem monitorar eventos relacionados com mutação gênica, aberrações cromossômicas e recombinação mitótica. O diagnóstico estatístico foi obtido pelo teste binomial condicional. Os resultados demonstraram que o EFV foi tóxico em altas concentrações, mas não induziu eventos tóxico genéticos. Inversamente, o TDF não apresentou toxicidade nas concentrações testadas, porém apresentou indução de efeitos tóxico genéticos em todas as concentrações, com prevalência dos eventos recombinogênicos. Então, torna-se fundamental analisar constantemente o risco/benefício de medicamentos isolados e identificar a atividade tóxica e tóxico-genética de cada fármaco com o intuito de assegurar qualidade de vida aos pacientes que fazem uso de monoterapias e oferecer suporte para as investigações com as terapias que utilizam combinações de antirretrovirais.

This study focused on two active pharmaceutical ingredients (APIs) that are used to treat two of the most notorious diseases in Africa, i.e. human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and malaria. It is well known that many African countries lack effective regulatory control over medicines and patients are subsequently at risk of receiving sub-standard treatments. This study set out to investigate how the modification of the crystal packing (i.e. polymorphism) of these APIs may impact on their quality, safety and efficacy. Efavirenz (an antiretroviral) and Pyrimethamine (an antimalarial) were selected as the two model APIs for investigation during this study. It was found that a novel amorphous form (Form A) of Efavirenz had been prepared during this study through quench cooling. Form A was extensively characterised and compared to the preferred crystalline Form I, with the aim of providing a means of distinguishing between these two Efavirenz forms. In contrast to popular belief (that amorphous form should have improved dissolution and solubility properties over the crystalline counterpart), the powder dissolution of Form A was significantly lower than that of Form I. Further investigation indicated that this was due to the occurrence of agglomeration and phase-mediated transformation. This observation had led to the belief that Form A had poor thermodynamic stability. The glass transition temperature and the crystallisation activation energy, required for the recrystallisation of Form A, were subsequently determined in an attempt to elucidate its thermodynamic stability. The glass transition temperature of Form A was found to be unfeasibly low, hence confirming its tendency towards agglomeration. The crystallisation activation energy of Form A was determined by non-isothermal determinations, using differential scanning calorimetry (DSC), hot stage microscopy (HSM) and capillary melting point (CMP) analysis. These studies not only elucidated the required activation energy for the conversion of Form A into Form I, but it also found that the results from CMP were similar to those of the universally accepted DSC technique, allowing for the proposal of CMP as a cost-effective alternative to DSC for the quantitative measurement of the crystallisation of Efavirenz. Isothermal studies revealed that Form A had a short half-life, which, together with its poor dissolution performance, exemplified why this form was unsuitable for pharmaceutical use. The Pyrimethamine study focused on recrystallisation as a means of modifying its crystal packing and on an evaluation of the effect that such crystal modification may have on its safety and manufacturability. Anhydrous Pyrimethamine was recrystallised, using methanol, acetone, n-propanol, ethanol, N,N-dimethylformamide and N,N-dimethylacetamide. Ethanol, acetone and n-propanol altered the crystal habit of Pyrimethamine, without any modification of its crystal lattice. The different habits exhibited clear differences in flowability and compressibility, which could in turn affect manufacturing and therefore the quality of the finished pharmaceutical product (FPP). These habits were subsequently extensively characterised by means of in-silico molecular modelling predictions. It was found that recrystallisation from methanol, N,N-dimethylformamide and N,N-dimethylacetamide had resulted in solvatomorphism. These solvatomorphs contained their respective solvents in concentrations exceeding the allowed residual solvent limits, as set by the International Conference on Harmonisation (ICH) guidelines. These undesirable solvatomorphs were also comprehensively characterised as a service to the pharmaceutical industry, in order to identify the distinct characteristics that distinguish these forms from the preferred non-toxic form, and to provide techniques for transforming the toxic forms into the non-toxic form. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

This study focused on two active pharmaceutical ingredients (APIs) that are used to treat two of the most notorious diseases in Africa, i.e. human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) and malaria. It is well known that many African countries lack effective regulatory control over medicines and patients are subsequently at risk of receiving sub-standard treatments. This study set out to investigate how the modification of the crystal packing (i.e. polymorphism) of these APIs may impact on their quality, safety and efficacy. Efavirenz (an antiretroviral) and Pyrimethamine (an antimalarial) were selected as the two model APIs for investigation during this study. It was found that a novel amorphous form (Form A) of Efavirenz had been prepared during this study through quench cooling. Form A was extensively characterised and compared to the preferred crystalline Form I, with the aim of providing a means of distinguishing between these two Efavirenz forms. In contrast to popular belief (that amorphous form should have improved dissolution and solubility properties over the crystalline counterpart), the powder dissolution of Form A was significantly lower than that of Form I. Further investigation indicated that this was due to the occurrence of agglomeration and phase-mediated transformation. This observation had led to the belief that Form A had poor thermodynamic stability. The glass transition temperature and the crystallisation activation energy, required for the recrystallisation of Form A, were subsequently determined in an attempt to elucidate its thermodynamic stability. The glass transition temperature of Form A was found to be unfeasibly low, hence confirming its tendency towards agglomeration. The crystallisation activation energy of Form A was determined by non-isothermal determinations, using differential scanning calorimetry (DSC), hot stage microscopy (HSM) and capillary melting point (CMP) analysis. These studies not only elucidated the required activation energy for the conversion of Form A into Form I, but it also found that the results from CMP were similar to those of the universally accepted DSC technique, allowing for the proposal of CMP as a cost-effective alternative to DSC for the quantitative measurement of the crystallisation of Efavirenz. Isothermal studies revealed that Form A had a short half-life, which, together with its poor dissolution performance, exemplified why this form was unsuitable for pharmaceutical use. The Pyrimethamine study focused on recrystallisation as a means of modifying its crystal packing and on an evaluation of the effect that such crystal modification may have on its safety and manufacturability. Anhydrous Pyrimethamine was recrystallised, using methanol, acetone, n-propanol, ethanol, N,N-dimethylformamide and N,N-dimethylacetamide. Ethanol, acetone and n-propanol altered the crystal habit of Pyrimethamine, without any modification of its crystal lattice. The different habits exhibited clear differences in flowability and compressibility, which could in turn affect manufacturing and therefore the quality of the finished pharmaceutical product (FPP). These habits were subsequently extensively characterised by means of in-silico molecular modelling predictions. It was found that recrystallisation from methanol, N,N-dimethylformamide and N,N-dimethylacetamide had resulted in solvatomorphism. These solvatomorphs contained their respective solvents in concentrations exceeding the allowed residual solvent limits, as set by the International Conference on Harmonisation (ICH) guidelines. These undesirable solvatomorphs were also comprehensively characterised as a service to the pharmaceutical industry, in order to identify the distinct characteristics that distinguish these forms from the preferred non-toxic form, and to provide techniques for transforming the toxic forms into the non-toxic form. / PhD (Pharmaceutics), North-West University, Potchefstroom Campus, 2015

Highly active antiretroviral therapy (HAART) has improved the life expectancy of HIV–1–infected patients dramatically since it was launched in 1996, but there are still many challenges in the provision of HAART, especially to children in resource limited countries. Efavirenz (EFV), a non–nucleoside reverse transcriptase inhibitor (NNRTI) forms part of the recommended national first line antiretroviral treatment regimen for children older than 3 years and weighing more than 10 kg in South Africa. Limited pharmacokinetic information on EFV plasma concentrations in sub–Saharan HIV–1– infected children is available. EFV is primarily metabolised by hepatic CYP2B6 isoenzymes. The CYP2B6 gene is characterised by extensive inter–individual variability in hepatic expression and activity. The single nucleotide change, 516G>T, on the CYP2B6 gene has consistently been associated with elevated EFV plasma levels in different ethnic populations and these are more frequently observed in populations of African descent. The recommended therapeutic range of EFV plasma levels is 1–4 ug/ml and the Cmin should be above 1 ug/ml. In this prospective study (PK/PD.EFV.07) cohort, 60 black children, both genders, with no prior exposure to antiretroviral therapy and eligible for antiretroviral therapy (ART) were enrolled and followed up at 1, 3, 6, 12, 18 and 24 months post HAART initiation. They all attended the outpatient clinic at Harriet Shezi Children’s Clinic, Chris Hani Baragwanath Hospital, Soweto, South Africa. The required ethics approval was obtained to conduct this study. The objectives of this investigation were to: develop and validate a suitable LCMS/ MS method to accurately determine plasma EFV levels from this study population, determine the prevalence and effect of CYP2B6 516G>T polymorphism on EFV plasma levels, determine the population pharmacokinetic clearance (CL/F) value of EFV, identify covariates that influence the clearance of EFV in HIV–1– infected children, and investigate specific pharmacodynamic effects and therapeutic outcomes of this EFV–based regimen within this paediatric population over the 24 months post–HAART initiation. The main findings of the measured mid–dose EFV plasma concentrations showed that sub–therapeutic concentrations (<1 ug/ml) accounted for 18% (116/649), within therapeutic range (1–4 ug/ml) represented 52.5% (341/649), and concentrations above the therapeutic range (>4 ug/ml) represented 29.5% (192/649). A significant number of the samples (47.5%) were outside the accepted therapeutic range during this 24 month follow–up period. Possible reasons contributing to this include genetic variation in drug metabolism and non–adherence. Genotype results on all 60 study participants were: 23% 516 T/T homozygotes, 42% 516 G/G homozygotes and 35% 516 G/T heterozygotes. The 516 T–allelic variant frequency was relatively high at 41%. This also supports and explains why such a large number (29.5%) of the mid–dose interval plasma samples were above (>4 ug/ml) the accepted therapeutic range. Repeated measures ANOVA confirmed that CYP2B6 516 G/G, G/T and T/T genotypes were consistently predictive of the log EFV concentrations at all times (P = 0.0001). The total median (IQR) EFV plasma concentrations over the 24 months post–HAART when pooled, were 6.36 (3.47 - 7.28) for T/T, 2.55 (1.62 - 3.59) for G/T, and 1.41 (1.02 - 1.74) ug/ml for G/G groups respectively (P<0.00001). Multiple comparisons by groups revealed that the EFV plasma concentrations between the T/T and G/G (P=0.000002) and between G/T and G/G (P=0.009) were statistically significant. However, the differences between the EFV plasma concentrations of the T/T and G/T groups were not significantly different (P=0.074). This supports previous results that the presence of the 516 T–allelic variant is responsible for the higher EFV plasma concentrations within individuals presenting with this single nucleotide mutation on the CYP2B6 gene. This EFV–based treatment was well tolerated even at plasma concentrations above the therapeutic range (>4 ug/ml) and most side effects subsided spontaneously. 89% of the participants were virally suppressed at 24 months post–HAART. The efficacy of this EFV–based treatment did not affect the three genotype groups differently and they showed similar improvement in their immunological (CD4–cell count and CD4%) markers and reduction in viral load over the 24 months post– HAART initiation. We found no association of the CYP2B6 516G>T polymorphism and side effects reported after 1 month of treatment within this study population. The final population pharmacokinetic (PK) estimates for EFV clearance (CL/F) were, 2.46, 4.60, and 7.33 l/h for the T/T, G/T, and G/G respective genotype groups. The volume of distribution (V/F) estimate was 89.52 l. The importance of interoccasion variability (IOV) in a PK model for a longitudinal study was again highlighted by this investigation. To our knowledge, this is the first study in black South African HIV–1–infected children with measured sequential EFV plasma concentrations which also investigated the influence of the CYP2B6 516G>T polymorphism on EFV plasma concentrations and the population clearance (CL/F) value of EFV in a longitudinal study over a period of 24 months post–HAART initiation. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Highly active antiretroviral therapy (HAART) has improved the life expectancy of HIV–1–infected patients dramatically since it was launched in 1996, but there are still many challenges in the provision of HAART, especially to children in resource limited countries. Efavirenz (EFV), a non–nucleoside reverse transcriptase inhibitor (NNRTI) forms part of the recommended national first line antiretroviral treatment regimen for children older than 3 years and weighing more than 10 kg in South Africa. Limited pharmacokinetic information on EFV plasma concentrations in sub–Saharan HIV–1– infected children is available. EFV is primarily metabolised by hepatic CYP2B6 isoenzymes. The CYP2B6 gene is characterised by extensive inter–individual variability in hepatic expression and activity. The single nucleotide change, 516G>T, on the CYP2B6 gene has consistently been associated with elevated EFV plasma levels in different ethnic populations and these are more frequently observed in populations of African descent. The recommended therapeutic range of EFV plasma levels is 1–4 ug/ml and the Cmin should be above 1 ug/ml. In this prospective study (PK/PD.EFV.07) cohort, 60 black children, both genders, with no prior exposure to antiretroviral therapy and eligible for antiretroviral therapy (ART) were enrolled and followed up at 1, 3, 6, 12, 18 and 24 months post HAART initiation. They all attended the outpatient clinic at Harriet Shezi Children’s Clinic, Chris Hani Baragwanath Hospital, Soweto, South Africa. The required ethics approval was obtained to conduct this study. The objectives of this investigation were to: develop and validate a suitable LCMS/ MS method to accurately determine plasma EFV levels from this study population, determine the prevalence and effect of CYP2B6 516G>T polymorphism on EFV plasma levels, determine the population pharmacokinetic clearance (CL/F) value of EFV, identify covariates that influence the clearance of EFV in HIV–1– infected children, and investigate specific pharmacodynamic effects and therapeutic outcomes of this EFV–based regimen within this paediatric population over the 24 months post–HAART initiation. The main findings of the measured mid–dose EFV plasma concentrations showed that sub–therapeutic concentrations (<1 ug/ml) accounted for 18% (116/649), within therapeutic range (1–4 ug/ml) represented 52.5% (341/649), and concentrations above the therapeutic range (>4 ug/ml) represented 29.5% (192/649). A significant number of the samples (47.5%) were outside the accepted therapeutic range during this 24 month follow–up period. Possible reasons contributing to this include genetic variation in drug metabolism and non–adherence. Genotype results on all 60 study participants were: 23% 516 T/T homozygotes, 42% 516 G/G homozygotes and 35% 516 G/T heterozygotes. The 516 T–allelic variant frequency was relatively high at 41%. This also supports and explains why such a large number (29.5%) of the mid–dose interval plasma samples were above (>4 ug/ml) the accepted therapeutic range. Repeated measures ANOVA confirmed that CYP2B6 516 G/G, G/T and T/T genotypes were consistently predictive of the log EFV concentrations at all times (P = 0.0001). The total median (IQR) EFV plasma concentrations over the 24 months post–HAART when pooled, were 6.36 (3.47 - 7.28) for T/T, 2.55 (1.62 - 3.59) for G/T, and 1.41 (1.02 - 1.74) ug/ml for G/G groups respectively (P<0.00001). Multiple comparisons by groups revealed that the EFV plasma concentrations between the T/T and G/G (P=0.000002) and between G/T and G/G (P=0.009) were statistically significant. However, the differences between the EFV plasma concentrations of the T/T and G/T groups were not significantly different (P=0.074). This supports previous results that the presence of the 516 T–allelic variant is responsible for the higher EFV plasma concentrations within individuals presenting with this single nucleotide mutation on the CYP2B6 gene. This EFV–based treatment was well tolerated even at plasma concentrations above the therapeutic range (>4 ug/ml) and most side effects subsided spontaneously. 89% of the participants were virally suppressed at 24 months post–HAART. The efficacy of this EFV–based treatment did not affect the three genotype groups differently and they showed similar improvement in their immunological (CD4–cell count and CD4%) markers and reduction in viral load over the 24 months post– HAART initiation. We found no association of the CYP2B6 516G>T polymorphism and side effects reported after 1 month of treatment within this study population. The final population pharmacokinetic (PK) estimates for EFV clearance (CL/F) were, 2.46, 4.60, and 7.33 l/h for the T/T, G/T, and G/G respective genotype groups. The volume of distribution (V/F) estimate was 89.52 l. The importance of interoccasion variability (IOV) in a PK model for a longitudinal study was again highlighted by this investigation. To our knowledge, this is the first study in black South African HIV–1–infected children with measured sequential EFV plasma concentrations which also investigated the influence of the CYP2B6 516G>T polymorphism on EFV plasma concentrations and the population clearance (CL/F) value of EFV in a longitudinal study over a period of 24 months post–HAART initiation. / Thesis (Ph.D. (Pharmacology))--North-West University, Potchefstroom Campus, 2011.

Made available in DSpace on 2014-06-12T23:13:53Z (GMT). No. of bitstreams: 2 arquivo3387_1.pdf: 2061951 bytes, checksum: fd7364db2c5330206dee42d1b44d140e (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Faculdade de Amparo à Ciência e Tecnologia do Estado de Pernambuco / Dentro do cenário brasileiro, o [(S)-6-Cloro-4-(ciclopropiletinil)-4-(trifluormetil)-2,4- Dihidro - 1H-3, 1-benzoxazin-2-ona], conhecido como efavirenz (EFZ), é atualmente o medicamento mais utilizado no tratamento da AIDS sendo de primeira escolha como antirretroviral, inibidor não competitivo da enzima transcriptase reversa (TR) do HIV-1. Atualmente, o governo do Brasil disponibiliza comprimidos revestido de efavirenz 600 mg, gratuitamente através do Programa DST-AIDS. Entretanto, esse fármaco por possuir uma baixa solubilidade, pode apresentar uma biodisponibilidade não adequada, o que interfere na ação terapêutica, sendo classificado de classe II (baixa solubilidade e alta permeabilidade), ou seja, praticamente insolúvel. Para incrementar a solubilidade do efavirenz, foram testadas novas técnicas, destacando-se a formação de complexos de inclusão com ciclodextrinas (CDs) e sistemas multicomponentes com polímeros hidrofílicos-CDs. No diagrama de solubilidade com complexo de inclusão utilizando a M&#946;CD a 20 mM, obteve-se melhor resultado, seguido de um aumento de 739,64% na solubilidade. Já no diagrama de solubilidade com o sistema multicomponente foi notado que com a adição de polímeros hidrofílicos, especificamente neste caso o PVP K30, houve ainda um incremento na solubilidade obtendo aumento de 812,44%, podendo de ser destacado que a adição do PVP K30 em concentrações elevadas mostrou-se eficaz, porém com a presença da M&#946;CD esse aumento na solubilidade do EFZ foi mais significativo O sistema multicomponente que se destacou foi o obtido através da técnica de malaxagem, EFZ M&#946;CD (20 mM) - PVP K30 (1%), possibilitando um incremento na solubilidade do fármaco, que na dissolução apresentou liberação superior a 80%. O DRX visualizou-se a diminuição dos principais picos do EFZ característicos da sua cristalinidade, principalmente no pico em 6,24°. Através do espectro na região de infravermelho com transformada de Fourier observou-se que a vibração do estiramento C&#8801;C em 2249 mostrase praticamente ausente no sistema MX, sugerindo que haja complexação da M&#946;CD nessa região do efavirenz, o ciclopropano. No DSC observou um aumento do PF do EFZ entre 123,31 e 145,20°C para 160,6°C e 168,7°C, onde da energia de entalpia foi elevada, caracterizando estabilidade do sistema. O processo de decomposição no TG ocorreu em três etapas características do EFZ, PVP K30 e da M&#946;CD, cuja perda de massa foi menor para todos os componentes. Porem, no MX a perda de massa do IFA foi significativamente inferior ao da MF, demonstrando que o produto obtido através da técnica de malaxagem proporcionou uma maior estabilidade ao EFZ. As eletromicrografias do MX evidenciaram a mudança de morfologia dos excipientes, juntamente com a inserção parcial do fármaco no sistema, corroborando com o DSC e DRX na diminuição da cristalinidade do IFA. Portanto, este trabalho é de caráter inovador, pois através de técnicas modernas, visa incrementar a solubilidade do EFZ, aumentando sua biodisponibilidade, possibilitando ampliar e facilitar seu uso no desenvolvimento em diversas formas farmacêuticas

Introduktion Under början av 1980-talet uppmärksammades ovanliga tumörer och infektioner hos unga män som vanligtvis drabbar personer med nedsatt immunförsvar. Forskargrupper i Frankrike och USA upptäckte 1983 och 1984 ett nytt virus som fick namnet humant immunbrist virus (HIV). En infektion av HIV fortlöper under många år asymtomatiskt och det är först när immunförsvaret är försvagat som symtom börjar märkas. Första läkemedlet som godkändes för att behandla HIV presenterades 1987 och dödligheten i följdsjukdomen Acquired Immunodeficiency Syndrome (AIDS) minskade drastiskt. Under 1996 infördes en ny behandling i form av kombinationer av tre eller fler läkemedel, som kom att kallas antiretroviral terapi (ART). Syfte Syftet med denna litteraturstudie är att ta reda på om det finns någon skillnad i effekt och säkerhet för ART-kombinationerna abakavir-lamivudin-atazanavir/r (ABC+3TC+ATV/r) och abakavir-lamivudin-efavirenz (ABC+3TC+EFV) som rekommenderas till tidigare obehandlade HIV-patienter. Metod Denna litteraturstudie baseras på nio originalartiklar hämtade från databasen PubMed mellan 19 januari och 7 februari 2016 med sökorden abacavir, lamivudine, atazanavir, efavirenz och efficacy, med begränsningarna english, clinical trial, adult: 19+ years. Antalet träffar sorterades utifrån inklusions- och exklusionskriterierna, att studierna undersökt effekt och säkerhet hos båda kombinationerna ABC+3TC+ATV/r och ABC+3TC+EFV i första hand eller mot andra kombinationer eller i monoterapi i andra hand, studierna ska ha pågått i minst 48 veckor och deltagarna ska ha varit 16 år eller äldre. Resultat och diskussion Nio studier uppfyllde inklusionskriterierna, åtta av dem var randomiserade. Fem av studierna jämförde båda kombinationerna och ytterligare fyra studier inkluderades som studerat en av kombinationerna mot andra kombinationer eller i monoterapi.Studierna påvisade ingen statistisk signifikant skillnad mellan kombinationerna. Antalet patienter som uppnått virushalt under gränsvärdet 50 kopior/ml var i åtta av nio studier fler än 70 %. Biverkningarna redovisades på olika sätt hos studierna, några av dem visade vilka som förekom mest och andra på enstaka metaboliska förändringar.Att studierna inte kunnat påvisa någon signifikant skillnad i effekt eller säkerhet kan vara en faktor som gjort att de valts till förstahandsval för patienter som tidigare inte behandlats med ART. Endast fem studier hade jämfört båda kombinationerna vilket gjorde att studier som jämfört en av kombinationer mot andra kombinationer eller i monoterapi inkluderats för att kunna jämföra effekten hos ART-kombinationerna. Säkerheten hos studierna redovisades på olika sätt vilket gjort att en jämförelse mellan preparatens biverkningar och tolerans varit svår att göra. Slutsats Ingen statistisk signifikant skillnad i effekt och säkerhet mellan kombinationerna har kunnat visas. Fler än 70 % av patienterna uppnådde virushalt &lt;50 kopior/ml efter 48 veckors behandling. Behandlingen tolererades av de flesta av patienterna och biverkningarna mellan kombinationerna skiljde sig inte åt.