Influence of isoniazid on T lymphocytes, cytokines, and macrophages in rats

T lymphocytes, cytokines, and macrophages play important roles in the clearance of Mycobacterium tuberculosis (Mtb) by the immune system. This study aimed to investigate the effects of isoniazid on the functions of both innate and adaptive immune cells. Healthy rats were randomly divided into experimental and control groups. Each group was randomly divided into three subgroups and named according to the duration of drug feeding, 1, 3, and 3 months followed by drug withdrawal for 1 month. The experimental groups were fed with isoniazid (12 mg/mL) and the control groups with normal saline. The percentage of CD4+ and CD8+T lymphocytes, level of interleukin (IL)-12 and interferon (IFN)-γ, and function of macrophages were determined at these three time points. Isoniazid significantly increased the percentage of CD4+T lymphocytes and the CD4+/CD8+T lymphocyte cell ratio (P < 0.05). It transiently (<1 month) enhanced the functions of rat macrophages significantly (P < 0.05). In summary, isoniazid could increase the percentage of CD4+T lymphocytes, CD4+/CD8+T lymphocyte cell ratio, and enhance macrophage function in healthy rats

Desarrollo de infección tuberculosa latente y efectos adversos de la isoniazida durante tratamiento con biológico por enfermedad de Crohn / Development of latent tuberculosis and adverse effects with isoniazid during biologist therapy´s in Crohn´s disease / Desenvolvimento de tuberculose latente durante e efeitos adversos da isoniazida o tratamento com biológicos para a doença de Crohn

Los fármacos anti factor de necrosis tumoral alfa (TNF-α) bloquean una de las citoquinas implicadas en la patogénesis de la Enfermedad Inflamatoria intestinal (EII). Su uso se relaciona con aumento de tuberculosis (TB), por lo que el despistaje previo es obligatorio. En la infección tuberculosa latente (ITBL) se utiliza isoniazida como quimioprofilaxis, fármaco que no se encuentra libre de reacciones adversas. Se presenta y discute el caso de una paciente con reacción adversa en piel secundaria al uso de isoniazida.

Anti-tumor necrosis factor alfa drugs are responsible for blocking one of the cytoquines implicated on inflammatory bowel disease pathogenesis. Its use has been linked to an increase in tuberculosis cases which is why screening before starting treatment is mandatory. Latent tuberculosis is treated with isoniazid as chemoprophylaxis although its use may provoke adverse effects. A case is presented of a patient with skin adverse reaction due to the use of isoniazid.

Os medicamentos anti factor de necrose tumoral alfa (TNF-α ) bloqueiam uma das citocinas envolvidas na patogénese da doença inflamatória intestinal (DII). A sua utilização está associada com um aumento da tuberculose (TB), de modo que a despistagem anterior dessa doença é necessária. Na TB latente, frequentemente se utiliza a isoniazida é usado como quimioprofilaxia, uma droga que não está livre de reações adversas. Apresentamos e discutimos o caso de uma paciente com reação adversa na pele secundária ao uso da isoniazida.

Drug-induced Hepatotoxicity of Anti-tuberculosis Drugs and Their Serum Levels

The correlation between serum anti-tuberculosis (TB) drug levels and the drug-induced hepatotoxicity (DIH) remains unclear. The purpose of this study was to investigate whether anti-TB DIH is associated with basal serum drug levels. Serum peak levels of isoniazid (INH), rifampicin (RMP), pyrazinamide (PZA), and ethambutol (EMB) were analyzed in blood samples 2 hr after the administration of anti-TB medication. Anti-TB DIH and mild liver function test abnormality were diagnosed on the basis of laboratory and clinical criteria. Serum anti-TB drug levels and other clinical factors were compared between the hepatotoxicity and non-hepatotoxicity groups. A total of 195 TB patients were included in the study, and the data were analyzed retrospectively. Seventeen (8.7%) of the 195 patients showed hepatotoxicity, and the mean aspartate aminotransferase/alanine aminotransferase levels in the hepatotoxicity group were 249/249 IU/L, respectively. Among the 17 patients with hepatotoxicity, 12 showed anti-TB DIH. Ten patients showed PZA-related hepatotoxicity and 2 showed INH- or RMP-related hepatotoxicity. However, intergroup differences in the serum levels of the 4 anti-TB drugs were not statistically significant. Basal serum drug concentration was not associated with the risk anti-TB DIH in patients being treated with the currently recommended doses of first-line anti-TB treatment drugs.

Drug-induced Hepatotoxicity of Anti-tuberculosis Drugs and Their Serum Levels

The correlation between serum anti-tuberculosis (TB) drug levels and the drug-induced hepatotoxicity (DIH) remains unclear. The purpose of this study was to investigate whether anti-TB DIH is associated with basal serum drug levels. Serum peak levels of isoniazid (INH), rifampicin (RMP), pyrazinamide (PZA), and ethambutol (EMB) were analyzed in blood samples 2 hr after the administration of anti-TB medication. Anti-TB DIH and mild liver function test abnormality were diagnosed on the basis of laboratory and clinical criteria. Serum anti-TB drug levels and other clinical factors were compared between the hepatotoxicity and non-hepatotoxicity groups. A total of 195 TB patients were included in the study, and the data were analyzed retrospectively. Seventeen (8.7%) of the 195 patients showed hepatotoxicity, and the mean aspartate aminotransferase/alanine aminotransferase levels in the hepatotoxicity group were 249/249 IU/L, respectively. Among the 17 patients with hepatotoxicity, 12 showed anti-TB DIH. Ten patients showed PZA-related hepatotoxicity and 2 showed INH- or RMP-related hepatotoxicity. However, intergroup differences in the serum levels of the 4 anti-TB drugs were not statistically significant. Basal serum drug concentration was not associated with the risk anti-TB DIH in patients being treated with the currently recommended doses of first-line anti-TB treatment drugs.

Desfechos clínicos do tratamento de tuberculose utilizando o esquema básico recomendado pelo Ministério da Saúde do Brasil com comprimidos em dose fixa combinada na região metropolitana de Goiânia / Clinical treatment outcomes of tuberculosis treated with the basic regimen recommended by the Brazilian National Ministry of Health using fixed-dose combination tablets in the greater metropolitan area of Goiânia, Brazil

OBJETIVO: Descrever as taxas de cura, falência e abandono do tratamento da tuberculose com o esquema básico preconizado pelo Ministério da Saúde (tratamento com rifampicina, isoniazida, pirazinamida e etambutol por dois meses seguido de isoniazida e rifampicina por quatro meses) utilizando comprimidos em dose fixa combinada em regime autoadministrado e descrever os eventos adversos e seus possíveis impactos nos desfechos do tratamento. MÉTODOS: Estudo descritivo utilizando dados coletados prospectivamente dos prontuários médicos de pacientes com tuberculose (idade > 18 anos) tratados com o esquema básico em duas unidades básicas de saúde da região metropolitana de Goiânia, GO. RESULTADOS: A amostra foi composta por 40 pacientes com tuberculose. A taxa de cura foi de 67,5%, a taxa de abandono foi de 17,5%, e não ocorreram casos de falência. Nessa amostra, 19 pacientes (47%) relataram reações adversas aos medicamentos. Essas foram leves e moderadas, respectivamente, em 87% e 13% dos casos. Em nenhum caso houve necessidade de mudança do esquema ou suspensão do tratamento. CONCLUSÕES: A taxa de cura do esquema básico com o uso de comprimidos em dose fixa combinada sob regime autoadministrado foi semelhante às taxas históricas do esquema anterior. A taxa de abandono, na amostra estudada, foi muito acima da taxa preconizada como adequada (até 5%).

OBJECTIVE: To describe the rates of cure, treatment failure, and treatment abandonment obtained with the basic regimen recommended by the Brazilian National Ministry of Health (rifampin, isoniazid, pyrazinamide, and ethambutol for two months, followed by isoniazid and rifampin for four months) involving the use of fixed-dose combination tablets (self-administered treatment), as well as to describe adverse events and their potential impact on treatment outcomes. METHODS: This was a descriptive study based on prospective data obtained from the medical records of tuberculosis patients (> 18 years of age) treated with the basic regimen at either of two primary health care facilities in the greater metropolitan area of Goiânia, Brazil. RESULTS: The study sample comprised 40 tuberculosis patients. The rate of cure was 67.5%, the rate of treatment abandonment was 17.5%, and there were no cases of treatment failure. Of the 40 patients in the sample, 19 (47%) reported adverse reactions, which were mild and moderate, respectively, in 87% and 13% of the cases. It was not necessary to alter the regimen or discontinue the treatment in any of the cases evaluated. CONCLUSIONS: The rate of cure obtained with the self-administered, fixed-dose combination tablet form of the new basic regimen was similar to the historical rates of cure obtained with the previous regimen. The rate of treatment abandonment in our sample was much higher than that considered appropriate (up to 5%).

Treatment Response and Adverse Reactions in Older Tuberculosis Patients with Immunocompromising Comorbidities

PURPOSE: The aim of this study was to elucidate the effects of immunocompromising comorbidities on treatment response and adverse reactions in older tuberculosis (TB) patients. MATERIALS AND METHODS: The medical records of 182 patients older than 65 years with proven TB by positive culture of Mycobacterium tuberculosis and with available drug susceptibility tests were reviewed retrospectively. These patients were subsequently assigned to either the comorbidity group (n=78) or non-comorbidity group (n=104) depending on whether they had immunocompromising comorbidities. RESULTS: The mean durations of treatment were 9.9+/-3.3 months in the comorbidity group and 9.3+/-3.2 months in the non-comorbidity group (p=0.21). M. tuberculosis culture results converted to negative in most patients with available follow-up cultures at two months after treatment. The successful treatment rates were 94.9% and 98.9% in the comorbidity and non-comorbidity groups, respectively (p=0.30). The most common side effects of anti-TB treatment were skin rash/pruritus (13% in the comorbidity group vs. 11% in the non-comorbidity group, p=0.79), gastro-intestinal problems (14% vs. 9%, p=0.25) and hepatotoxicity (14% vs. 7%, p=0.09). CONCLUSION: The present study shows that the successful treatment rate for TB is high and that immunocompromising comorbidities have no effect on the response to treatment and adverse effects in older TB patients.

Tratamiento directamente observado de la tuberculosis en un hospital de la Ciudad de Buenos Aires / Directly observed treatment for tuberculosis in a Buenos Aires City hospital

Se describe la experiencia en la aplicación del tratamiento directamente observado de tuberculosis (TDO) en el período 1/1/1979-31/12/2009 y la comparación de los resultados obtenidos en el periodo 1979-1999 versus los de 2000- 2009. En un hospital de la Ciudad de Buenos Aires, 582 pacientes HIV negativos recibieron inicialmente rifampicina, isoniazida, pirazinamida y etambutol o estreptomicina. En la segunda fase 424 de estos pacientes tratados entre 01/01/1979 y 31/12/1999 (G1), recibieron esquemas bisemanales con rifampicina/isoniazida o isoniazida/estreptomicina y otros 158 pacientes, tratados entre 01/01/2000 y 31/12/2009 (G2) recibieron un esquema bisemanal o trisemanal con rifampicina/isoniazida. Se siguieron las recomendaciones de los programas de control de la Nación y la Ciudad. Los pacientes bajo TDO tuvieron tasas de tratamiento completo más elevadas (82.8% versus 48.7%), (p < 0.0001) con respecto a otros 483, que siguieron tratamiento autoadministrado (AUTO); la edad promedio fue de 36.3 ± 15.3 años, 63.1% eran varones y 69.4% tenían nacionalidad argentina. Presentaron tratamiento previo el 8.9%, comorbilidades el 6.1% y el 70.6% de las formas pulmonares fueron confirmadas bacteriológicamente. El 9.5% presentó efectos adversos a drogas y el sexo masculino presentó mayor frecuencia de abandonos (p = 0.004). Con respecto al G1, en el G2 hubo menor proporción de pacientes argentinos (48.7% vs. 77.1%), (p ≤ 0.0001), mayor frecuencia de comorbilidades (10.7% vs. 4.4%), (p = 0.005), de formas clínicas pulmonares con confirmación bacteriológica (95% vs. 87%), (p = 0.02) y de efectos adversos a drogas (17% vs. 6.6%), (p ≤ 0.0001). Hallamos tasas de cumplimiento total elevadas en TDO (82.8%), similares a las otras publicaciones.

The outcomes of directly observed therapy of tuberculosis (DOT) between 1/1/1979 and 12/31/2009 were analyzed. Results obtained in the 1979-1999 period were compared with those achieved in the 2000-2009 period. In a Buenos Aires City hospital, 582 HIV negative TB patients received rifampin, isoniazid, pyrazinamide and ethambutol or streptomycin in the initial stage, followed by a second stage where patients were included in two groups: G1 composed by 424 patients (period 1/1/1979-12/31/1999) who received either rifampin and isoniazid or rifampin and streptomicin twice a week, and G2, with 158 patients (period 1/1/2000-12/31/2009) who received either rifampin and isoniazid twice or three times a week. National and Buenos Aires City TB Control Programs recommendations were followed. Patients who underwent DOT had higher completeness rates than those included in self-administered therapy (82.8% vs. 48.7%), (p <0.0001). Mean age: 36.3±15.3 years, males: 63.1% and 69.4% were Argentine citizens. A 8.9% had been previously treated, 6.1% had co-morbidities. A 70.6% of pulmonary cases was bacteriologically confirmed, 82.8% of them completed the treatment, while 11.5% defaulted. Adverse effects to antituberculosis drugs were observed in 9.5% of cases; male patients showed higher rates of non adherence. G2 had a lower proportion of native people (48.7% vs. 77.1%), (p ≤ 0.0001), higher frequency of co-morbidities (10.7% vs. 4.4%), (p = 0.005), of bacteriologically confirmed pulmonary cases (95% vs. 87%), (p = 0.02) and more adverse effects than G1 (17% vs. 6.6%), (p ≤ 0.0001). In coincidence with other experiences, this work shows high treatment success rates in patients treated under DOT strategy.

Falla hepática secundaria a toxicidad por tuberculostáticos: Caso clínico / Fulminant hepatic failure due to tuberculostatic drugs: Case report

La toxicidad hepática por isoniacida, sobre todo asociada a rifampicina, es un raro efecto adverso de la terapia antituberculosa. En EE.UU., es la causa de 0,2% de los trasplantes hepáticos pediátricos y del 14% de los trasplantes por toxicidad medicamentosa. Comunicamos el caso de una paciente de 10 años de edad con falla hepática fulminante que requirió trasplante hepático luego de cuarenta días de tratamiento tuberculostático con isoniacida, rifampicina y pirazinamida.

Hepatoxicity of isoniazid, mainly in association with rifampin, is a rare secondary effect of tuberculostatic treatment. In the United States, it accounts for 0.2% of all pediatric orthotropic liver transplant, and 14% of transplants for drug hepatotoxicity. We report the case of a 10 year-old patient who presented with acute liver failure requiring orthotropic liver transplant after forty days of tuberculostatic treatment with isoniazid, rifampin and pyrazinamide.

Resposta paradoxal após o início de tratamento para tuberculose: relato de caso / Paradoxical response after initiation of tuberculosis treatment: case report

JUSTIFICATIVA E OBJETIVOS: A reação paradoxal pode ser identificada em até 30% de todos os pacientes após o início de tratamento para tuberculose, embora seu diagnóstico permaneça um desafio, já que não existem testes confiáveis que o corroborem. O objetivo deste estudo foi relatar um caso em que o diagnóstico de reação paradoxal foi realizado.RELATO DO CASO: Paciente do sexo masculino, 31 anos,um mês após o início de uso de fármacos para tratamento de tuberculose miliar, com diagnóstico realizado por lavado broncoalveolar, apresentou plegia no membro inferior direito, parestesia no membro superior direito e membro inferior esquerdo, incontinência urinária e fecal. Ressonância nuclear magnética do encéfalo evidenciou múltiplas áreas com hipersinal em T2, predominando em substância branca subcortical em ambos os hemisférios, com realce de lesões nodulares, sugestivas de infecção oportunista. Antivírus da imunodeficiência humana 1/2 foi negativo. PCR DNA para M. tuberculosis no líquor foi negativa. Iniciou-se, então, dexametasona. O paciente apresentou melhora significativa, porém permaneceu com incontinência urinária.Tomografia computadorizada de crânio realizada posteriormente não evidenciou quaisquer alterações. CONCLUSÃO: Apesar de sua elevada prevalência, continua difícilr ealizar o diagnóstico de reação paradoxal após o início de tratamento para tuberculose. Mais estudos são necessários para melhor definir os parâmetros diagnósticos e para orientar diretrizes terapêuticas mais efetivas.

BACKGROUND AND OBJECTIVES: Paradoxical response can be identified in up to 30% of all patients after initiation of tuberculosis treatment, although your diagnosis still remains a challenge, mainly because do not exist trustworthy tests to confirm it. These study aimed to describe a case were the diagnosis of a paradoxical response was made.CASE REPORT: Male patient, 31 year-old, a month after the initiation of miliary tuberculosis treatment, with the diagnosis realized by bronchoalveolar lavage, presented right lower limb plegia, right upper limb paresthesia, urge and fecal incontinence. Brain Magnetic Resonance Imaging evidenced hyper signs of T2 in multiple areas, in which predominated in white subcortical substance, beyond enhancing nodular lesions, suggesting an opportunistic infection. Anti human immunodeficiency virus 1/2 was negative. PCR DNA to M. tuberculosis in liquor was negative. After, dexamethasone treatment was started. The patient presented a significant improvement, but urge incontinence remained unchanged. Brain computed tomography realized after not evidence any alteration. CONCLUSION: Despite paradoxical response presents high occurrence, it continuous to be difficult to make the diagnosis of paradoxical response after initiation of tuberculosis treatment. Further studies are necessary in order to improve the diagnostic parameters and to orientate more effective therapeutic consensus.

Genetic polymorphisms of NAT2, CYP2E1 and GST enzymes and the occurrence of antituberculosis drug-induced hepatitis in Brazilian TB patients

Isoniazid (INH), one of the most important drugs used in antituberculosis (anti-TB) treatment, is also the major drug involved in hepatotoxicity. Differences in INH-induced toxicity have been attributed to genetic variability at several loci, such as NAT2, CYP2E1, GSTM1 and GSTT1, that code for drug-metabolising enzymes. Our goal was to examine the polymorphisms in these enzymes as susceptibility factors to anti-TB drug-induced hepatitis in Brazilian individuals. In a case-control design, 167 unrelated active tuberculosis patients from the University Hospital of the Federal University of Rio de Janeiro, Brazil, were enrolled in this study. Patients with a history of anti-TB drug-induced acute hepatitis (cases with an increase to 3 times the upper limit of normal serum transaminases and symptoms of hepatitis) and patients with no evidence of anti-TB hepatic side effects (controls) were genotyped for NAT2, CYP2E1, GSTM1 and GSTT1 polymorphisms. Slow acetylators had a higher incidence of hepatitis than intermediate/rapid acetylators [22 percent (18/82) vs. 9.8 percent (6/61), odds ratio (OR), 2.86, 95 percent confidence interval (CI), 1.06-7.68, p = 0.04). Logistic regression showed that slow acetylation status was the only independent risk factor (OR 3.59, 95 percent CI, 2.53-4.64, p = 0.02) for the occurrence of anti-TB drug-induced hepatitis during anti-TB treatment with INH-containing schemes in Brazilian individuals.

Hígado y terapia antituberculosa / Hepatotoxicity of antituberculosis therapy

La toxicidad hepática en pacientes tratados con drogas antituberculosas es relativamente infrecuente, probablemente debido a este hecho no contamos con una buena definición de toxicidad hepática. Existen algunas condiciones de los enfermos en que la hepatotoxicidad es más frecuente, tales como pacientes envejecidos, bebedores de alcohol, desnutrición, uso de ciertas drogas e hipoalbuminemia. Las drogas antituberculosas más frecuentemente involucradas en hepatotoxicidad son la pirazinamida, la isoniacida y la rifampicina. En este artículo analizamos el problema clínico de la hepatotoxicidad de la terapia antituberculosa y proponemos el manejo de diferentes situaciones. Discutimos cuando se debe suspender la administración de una droga, cómo se debe evaluar el daño hepático y qué drogas alternativas pueden usarse durante el tratamiento de la tuberculosis.

Liver toxicity in patients being treated with antituberculosis drugs is relatively uncommon, although transient elevation of liver enzymes is very common. Probably because of this there is not a good definition for liver toxicity. There are conditions in which hepatotoxicity is more frequent, such as elderly patients, alcohol consumption, malnutrition, use of certain drugs, and hypoalbuminemia. Pirazinamide, isoniazid and rifampicin are the antituberculosis drugs more commonly involved in liver toxicity. In this article we analyze the clinical problem of hepatotoxicity of antituberculosis therapy and propose the management of different situations. We discuss when a drug administration should be discontinued, how liver damage should be assesed and which alternative drugs should be used during the antituberculosis treatment.

Antituberculosis drug-induced hepatotoxicity: a comparison between patients with and without human immunodeficiency virus seropositivity / Hepatotoxicidade induzida pelos tuberculostáticos: comparação em pacientes com e sem soropositividade para o vírus da imunodeficiência humana

INTRODUCTION: The prevalence and risk factors for rifampin, isoniazid and pyrazinamide hepatotoxicity were evaluated in HIV-infected subjects and controls. METHODS: Patients with tuberculosis (30 HIV positive and 132 HIV negative), aged between 18 and 80 years-old, admitted to hospital in Brazil, from 2005 to 2007, were selected for this investigation. Three definitions of hepatotoxicity were used: I) a 3-fold increase in the lower limit of normal for alanine-aminotransferase (ALT); II) a 3-fold increase in the upper limit of normal (ULN) for ALT, and III) a 3-fold increase in the ULN for ALT plus a 2-fold increase in the ULN of total bilirubin. RESULTS: In groups with and without HIV infection the frequency of hepatotoxicity I was 77 percent and 46 percent, respectively (p < 0.01). Using hepatotoxicity II and III definitions no difference was observed in the occurrence of antituberculosis drug-induced hepatitis. Of the 17 patients with hepatotoxicity by definition III, 3 presented no side effects and treatment was well tolerated. In 8 (36.4 percent) out of 22, symptoms emerged and treatment was suspended. Alcohol abuse was related to hepatotoxicity only for definition I. CONCLUSIONS: Depending on the definition of drug-induced hepatitis, HIV infection may or may not be associated with hepatotoxicity. The impact that minor alterations in the definition had on the results was impressive. No death was related to drug-induced hepatotoxicity. The emergence of new symptoms after initiating antituberculosis therapy could not be attributed to hepatotoxicity in over one third of the cases.

INTRODUÇÃO: Avaliou-se a prevalência e os fatores de risco para hepatotoxicidade aos tuberculostáticos em pacientes HIV positivos e controles. MÉTODOS: Selecionou-se 162 pacientes com tuberculose, tratados com rifampicina, isoniazida e pirazinamida, na faixa etária de 18 a 80 anos, internados em hospital público no Brasil, entre 2005 e 2007. Eles foram divididos em dois grupos: 30 infectados pelo HIV e 132 controles. Adotou-se três definições para hepatotoxicidade: I) aumento de três vezes no valor inferior normal da alanina-aminotransferase (ALT); II) aumento de três vezes no valor superior normal (VSN) da ALT; III) aumento de três vezes no VSN da ALT e duas vezes no VSN da bilirrubina total. RESULTADOS: Nos grupos com e sem infecção pelo HIV, a frequência de hepatotoxicidade I foi de 77 por cento e 46 por cento, respectivamente (p<0,01). Para as definições II e III a frequência de hepatotoxicidade não diferiu entre os grupos estudados. De 17 pacientes com hepatotoxicidade induzida por droga (definição III), três não apresentaram sintomas e o tratamento foi mantido sem intercorrências. Oito (36,4 por cento) de 22 indivíduos apresentaram efeitos colaterais e interromperam o tratamento, mas não apresentavam hepatotoxicidade pela definição III. O abuso de álcool associou-se à hepatotoxicidade apenas para a definição I. CONCLUSÕES: Na dependência da definição escolhida, a infecção pelo HIV pode ou não associar-se à hepatotoxicidade. Foi grande o impacto que pequenas alterações na definição de hepatotoxicidade tiveram nos resultados. Nenhuma morte associou-se ao uso de tuberculostáticos. O surgimento de sintomas não pôde ser atribuído aos tuberculostáticos em um terço dos casos.

Hepatotoxicity of ATT

To determine the frequency of hepatotoxicity with standard ATT. Descriptive. Department of Medicine, Combined Military Hospital Lahore. Feb 2007 to April 2008. 250 patients aged 18 years or greater having pulmonary TB were selected through non-probability convenience sampling technique. All patients were given four drugs for two months indoors, followed by two drugs for four months in outdoor. Symptoms suggestive of hepatotoxicity were enquired from the patients regularly. Serum bilirubin and ALT were measured on monthly basis and finally on completion of therapy. Hepatotoxicity was defined as a five fold rise in serum ALT. In patients developing hepatotoxicity, treatment was modified accordingly. This study was done on 189 male and 61 female patients [total: 250]. Hepatotoxicity developed in 13 [5.2%] patients, mostly during the initial phase of treatment [84.6% incidence during the first month]. Risk factors included: age [4 out of 156 young patients and 9 out of 94 older patients; p: 0.016] and nutritional status [8 malnourished patients and 5 well nourished patients; p: 0.031]. Hepatotoxicity was not related to the gender [9 males and 4 females; p: 0.585] or the results of baseline sputum smears [7 out of 102 smear positive cases and six out of 148 smear negative cases; p: 0.064]. Hepatotoxicity with ATT is fairly common, especially in the elderly, malnourished patients and during the initial phase of treatment

Effectiveness and safety of isoniazid chemoprophylaxis for HIV-1 infected patients from Rio de Janeiro

The clinical and epidemiological characteristics, adverse events, treatment adherence and effectiveness of isoniazid chemoprophylaxis were analyzed in a cohort of 138 tuberculosis/HIV-coinfected patients. An open, non-randomized, pragmatic prophylactic trial was conducted on adult patients with a normal chest X-ray and positive tuberculin skin test (> 5 mm) who received isoniazid chemoprophylaxis (300 mg/day) for six months. The mean of follow up was 2.8 years (SD 1.3). Adherence to chemoprophylaxis was 87.7 percent (121/138). Only one patient presented tuberculosis after the end of chemoprophylaxis, corresponding to 0.3 cases per 100 persons per year. The relative risk of some adverse effects was 4.6 times higher (95 percent CI: 1.9-11.5) in patients with positive anti-HCV serology (4/9, 44.4 percent) compared to those with negative serology (12/129, 9.6 percent) (p = 0.002). This study provides evidence regarding the effectiveness and safety of a short and self-administered isoniazid regimen. We recommend the implementation of this routine by health service practitioners.

Variantes genéticas da N-acetiltransferase 2, CYP2E1 e glutationa S-transferase: relação com a segurança terapêutica em pacientes com tuberculose / Genetic variants of N-acetyltransferase 2, CYP2E1 and glutathione S-transferase: relation with therapeutic safety in patients with tuberculosis

Polimorfismos nos genes da n-acetiltransferase 2 (NAT2), CYP2E1 e glutationa S-transferase (GST) têm sido associados a diferenças na resposta ao tratamento da tuberculose. O papel de variantes dos genes NAT2, CYP2E1 e GSTM1/GSTT1, no perfil de segurança do tratamento da tuberculose, foi avaliado em 99 pacientes com tuberculose, sem co-infecção por HIV ou vírus da hepatite, tratados por 6 meses. Amostras de sangue foram colhidas antes e durante o tratamento para avaliação de marcadores de lesão hepatocelular (ASL T e AST), colestase (ALP, GGT e bilirrubinas) e função renal (creatinina). O DNA genômico foi extraído de sangue colhido em EDTA pelo método precipitação salina. Os polimorfismos NAT2 foram analisados por PCR-RFLP e seqüenciamento de DNA. Os polimorfismos da região promotora do CYP2E1 foram detectados por PCR-RFLP e para a análise dos genótipos nulos de (GSTM1*0) foi utilizada a PCR multiplex. Durante o tratamento, 59,6% dos pacientes apresentaram reações adversas aos medicamentos (RAM) e alterações nos marcadores de lesão hepatocelular e colestase, com aumento de 1 a 4 vezes o limite superior de referência. Foi observada forte relação entre RAM e alterações nos marcadores séricos (p< 0,05) e também com o uso de medicação concomitante (p< 0,001)...

Isoniazid Toxicity Presenting As Status Epilepticus and Severe Metabolic Acidosis.

Isoniazid (INH) is an integral component of treatment of tuberculosis. An acute overdose is potentially fatal and is characterized by the clinical triad of repetitive seizures unresponsive to the usual anticonvulsants, metabolic acidosis with a high anion gap and coma. The diagnosis of INH overdose should be considered in any patient who presents to emergency medical services (EMS) with the triad. We report a patient presenting with multiple generalised tonic clonic (GTC) convulsions with severe metabolic acidosis as a manifestation of INH toxicity. ©

Ginecomastia: um efeito colateral raro da isoniazida / Gynecomastia: a rare adverse effect of isoniazid

Relata-se o caso de um paciente que desenvolveu ginecomastia duas vezes após tratamento para tuberculose. Homem de 18 anos de idade foi tratado com o esquema isoniazida-rifampicina-pirazinamida; no terceiro mês desenvolveu ginecomastia bilateral, dolorosa, com regressão parcial ao final do tratamento. Foi retratado oito anos após com o mesmo regime, e a ginecomastia recorreu após seis meses de tratamento. Dosagens hormonais foram normais, e a mamografia revelou ginecomastia bilateral. A isoniazida foi suspensa, tendo a ginecomastia regredido parcialmente no final do tratamento. Quatro anos após, não foi constatada ginecomastia. Conclui-se que a ginecomastia relacionada à isoniazida regride totalmente após a suspensão da droga e, portanto, o tratamento cirúrgico ou medicamentoso deve ser evitado.

We report the case of a patient who twice developed gynecomastia following tuberculosis treatment. An 18-year-old male developed painful bilateral gynecomastia after three months of treatment with the isoniazid-rifampin-pyrazinamide regimen. Partial resolution of gynecomastia was achieved at the end of treatment. The patient was retreated with the same regimen eight years later, and gynecomastia recurred after six months of treatment. Hormone levels were normal, and a mammogram revealed bilateral gynecomastia. The isoniazid was discontinued, and the gynecomastia was partially resolved by the end of treatment. Four years later, gynecomastia was not detected. We conclude that isoniazid-related gynecomastia completely resolves when the medication is discontinued. Therefore, pharmacological and surgical treatment should be avoided.

Effect of different doses of carotenoids in isoniazid-rifampicin induced hepatotoxicity in rats.

AIM: Isoniazid (INH) and Rifampicin (RIF) are hepatotoxic drugs. Oxidative stress has been reported as one of the mechanisms of INH+RIF induced hepatotoxicity. METHODS: Intragastric administration of INH and RIF (50 mg/kg body weight/day each) for 28 days in Wistar rats is hepatotoxic, indicated by raised transaminases and histology. Carotenoids have antioxidant properties. Therefore, different doses of carotenoids (2.5, 5, 10 and 20 mg/kg body weight/day) were administered to study the hepatoprotective effect against INH+RIF. RESULTS: The higher doses of carotenoids i.e.10 and 20 mg/kg body weight/day showed partial hepatoprotection indicated by return to normal of liver transaminase level and of liver histology in 33.3% of rats. There was no further protective effect seen by increasing the dose of carotenoids from 10 to 20 mg/kg body weight/day. Lower doses of carotenoids, i.e., 2.5 and 5 mg/kg body weight/day were not effective. CONCLUSION: Thus, a minimum dose with maximum hepatoprotection (10 mg/kg b.wt/ day) was selected as the optimum dose in the present study. The hepatoprotective nature of carotenoids in INH+RIF treated rats may be attributed to their antioxidative property.