Molecular and cellular remodeling of HepG2 cells upon treatment with antitubercular drugs.

Drug-induced liver injury (DILI) is an adverse outcome of the currently used tuberculosis treatment regimen, which results in patient noncompliance, poor treatment outcomes, and the emergence of drug-resistant tuberculosis. DILI is primarily caused by the toxicity of the drugs and their metabolites, which affect liver cells, biliary epithelial cells, and liver vasculature. However, the precise mechanism behind the cellular damage attributable to first-line antitubercular drugs (ATDs), as well as the effect of toxicity on the cell survival strategies, is yet to be elucidated. In the current study, HepG2 cells upon treatment with a high concentration of ATDs showed increased perforation within the cell, cuboidal shape, and membrane blebbing as compared with control/untreated cells. It was observed that ATD-induced toxicity in HepG2 cells leads to altered mitochondrial membrane permeability, which was depicted by the decreased fluorescence intensity of the MitoRed tracker dye at higher drug concentrations. In addition, high doses of ATDs caused cell damage through an increase in reactive oxygen species production in HepG2 cells and a simultaneous reduction in glutathione levels. Further, high dose of isoniazid (50-200 mM), pyrazinamide (50-200 mM), and rifampicin (20-100 µM) causes cell apoptosis and affects cell survival during toxic conditions by decreasing the expression of potent autophagy markers Atg5, Atg7, and LC3B. Thus, ATD-mediated toxicity contributes to the reduced ability of hepatocytes to tolerate cellular damage caused by altered mitochondrial membrane permeability, increased apoptosis, and decreased autophagy. These findings further emphasize the need to develop adjuvant therapies that can mitigate ATD-induced toxicity for the effective treatment of tuberculosis.

Pyrazinamide related prolonged drug-induced liver injury: A case report.

RATIONALE: Drug induced liver injury (DILI) is a common side effect causing treatment discontinuation during tuberculosis (TB) treatment, and pyrazinamide (PZA) usually leads to a delayed and prolonged abnormal liver function of the 4 standard anti-tuberculosis regimens. However, a prolonged hepatitis lasting more than 4 months is rarely reported. PATIENT CONCERNS: A 78-year-old man presented with general weakness and poor appetite on his seventh week of anti-TB treatment for tuberculosis lymphadenitis. DIAGNOSIS: Drug induced liver injury, PZA-related. NAT2 slow acetylator phenotype was accidentally found during workup of DILI. INTERVENTION: A liver biopsy was performed and PZA-related DILI was suspected. All anti-TB medications were therefore discontinued. OUTCOME: After withholding all anti-TB medications for 4 months, the elevations of aminotransferases and hyperbilirubinemia completely resolved. Anti-TB therapy was switched to ethambutol and levofloxacin for 15 months without adverse events. Long-term ultrasound follow-up was performed and cervical lymphadenopathy completely resolved. CONCLUSION: Our patient presents with PZA related prolonged DILI resolved after drug discontinuation for 4 months. NAT2 slow acetylator phenotype may be related to this condition through unknown mechanisms.

Ameliorative potential of Adhatoda vasica against anti-tubercular drugs induced hepatic impairments in female Wistar rats in relation to oxidative stress and xeno-metabolism.

ETHNOPHARMACOLOGICAL RELEVANCE: Adhatoda vasica Nees is widely used herb of indigenous system to treat various ailments especially upper respiratory tract infections. Not only, anti-tubercular efficacy of crude extract and phytoconstituents of A. vasica has been documented but its hepatoprotective role against various drugs mediated hepatic alterations in different animal models has also been observed. BACKGROUND AND PURPOSE: Isoniazid, rifampicin and pyrazinamide (H-R-Z) are anti-tubercular drugs normally prescribed by health professionals for the treatment of tuberculosis, however along with their medical effectiveness these drugs also exhibit hepatotoxicity among TB patients. Unexpectedly, substantial toxicological data on the metabolism of anti-TB drugs are available but the mystery behind these xenobiotics is too complex and partly implicit. In this study, we further explored the hepatotoxic effects of these xeno-metabolic products and their amelioration by Adhatoda vasica Nees by elucidating its mechanistic action. METHODS: We generated a hepatotoxic rodent model by oral administration of H, R and Z (30.85, 61.7 and 132.65 mg/kg body weight) drugs for 25 days in Wistar rats. Additionally, to achieve hepatoprotection two different doses of Adhatoda vasica Nees ethanolic leaf extract (200 and 300 mg/kg body weight) were used along with H-R-Z dosage, orally and once daily for 25 days and tried to ascertain their mechanistic action. For this, initially phytoconstituents of the extract were evaluated followed by extract standardization using RP-HPLC and FTIR methods. Furthermore, antioxidant activity of the extract was analyzed by DPPH assay. Finally, different treated groups were analyzed for hepatic oxidative stress markers, antioxidant markers, histopathological changes and gene expression study including CYP2E1, CYP7A1, NAT, NR1I2 and UGT1A1 genes involved in phase I and phase II xeno-metabolism. RESULTS: Estimated content of vasicine in RP-HPLC method and free-radical scavenging activity in DPPH assay was found to be 134.519 ± 0.00269µg/10mg of leaf extract and 47.81 µg/mL respectively. In H-R-Z treated group, a significant increase in the levels of thiobarbituric acid, significant reduction in the levels of GSH, and enzymatic markers and marked changes in hepatic histological architecture were observed. In addition, there was significance up-regulation of CYP7A and NAT genes, down-regulation of CYP2E1 gene and insignificant expression levels of NR1I2 and UGT1A1 genes were observed in H-R-Z group. Conversely, high dose of A. vasica extract effectively diminished these alterations by declining oxidative stress and boosting of antioxidant levels. In addition, it acted as bi-functional inducer of both phase I (CYP2E1) and phase II (NAT and UGT1A1) enzyme systems. CONCLUSION: Hence, we concluded that anti-TB drugs exposure has potential to generate reactive metabolites that eventually cause hepatotoxicity by altering oxidant-antioxidant levels and their own metabolism. This study not only emphasized on xeno-metabolism mediated hepatic alterations but also explore the benefit of A. vasica on these toxic insults.

Optimal Design, Characterization and Preliminary Safety Evaluation of an Edible Orodispersible Formulation for Pediatric Tuberculosis Pharmacotherapy.

The severity of tuberculosis (TB) in children is considered a global crisis compounded by the scarcity of pharmaceutical formulations suitable for pediatric use. The purpose of this study was to optimally develop and evaluate a pyrazinamide containing edible orodispersible film formulation potentially suitable for use in pediatrics actively infected with TB. The formulation was prepared employing aqueous-particulate blending and solvent casting methods facilitated by a high performance Box Behnken experimental design template. The optimized orodispersible formulation was mechanically robust, flexible, easy to handle, exhibited rapid disintegration with initial matrix collapse occurring under 60 s (0.58 ± 0.05 min ≡ 34.98 ± 3.00 s) and pyrazinamide release was controlled by anomalous diffusion coupled with matrix disintegration and erosion mechanisms. It was microporous in nature, light weight (57.5 ± 0.5 mg) with an average diameter of 10.5 mm and uniformly distributed pyrazinamide load of 101.13 ± 2.03 %w/w. The formulation was physicochemically stable with no evidence of destructive drug-excipient interactions founded on outcomes of characterization and environmental stability investigations. Preliminary inquiries revealed that the orodispersible formulation was cytobiocompatible, palatable and remained intact under specific storage conditions. Summarily, an edible pyrazinamide containing orodispersible film formulation was optimally designed to potentially improve TB pharmacotherapy in children, particularly the under 5 year olds.

Long-term efficacy of 6-month therapy with isoniazid and rifampin compared with isoniazid, rifampin, and pyrazinamide treatment for pleural tuberculosis.

Research into anti-tuberculosis treatment has mainly focused on pulmonary tuberculosis (TB), with few studies on pleural-TB. The aim of the study is to compare the long-term efficacy of a 6-month treatment regimen with isoniazid and rifampicin (6HR) with treatment regimen of isoniazid, rifampicin, and pyrazinamide (6HR2Z) for pleural-TB. A case-control study of 200 HIV-negative patients with pleural-TB prospectively followed in our TB-unit from 1995 to 2018. The primary resistance to isoniazid is < 4% in our geographic area. Pleural-TB diagnosis was based on a positive culture for M. tuberculosis (84 patients), presence of caseating granulomas in pleural biopsy (28), or characteristics of pleural fluid (88). A comparative study of demographic and clinical characteristics between the treatment groups was carried out. Out of the 200 patients followed, (112 males, 88 females; mean age 32.9 ± 18.4 years), 99 patients were treated with 6HR regimen and 101 with 6HR2Z. The groups were comparable, except the 6HR2Z had larger size of pleural effusion. All patients completed the treatment. The group treated with 6HR presented fewer adverse effects (15.3%) than 6HR2Z group (33%), p = 0.005, and lower frequency of severe hepatic toxicity (5% vs 10.9%). Four patients died from causes other than TB during treatment with 6HR2Z, and all other patients were cured during a monitoring period for 8.4 years (IQRs, 3.3-14.3). Six patients in 6HR and 10 in 6HR2Z developed residual pachypleuritis. 6HR is as effective as 6HR2Z treatment for pleural-TB, with fewer adverse effects.

Association between TXNRD1 polymorphisms and anti-tuberculosis drug-induced hepatotoxicity in a prospective study.

Anti-tuberculosis drug-induced hepatotoxicity (ATDH) is a serious adverse reaction to anti-tuberculosis (TB) treatment. Thioredoxin reductase 1 (TXNRD1), encoded by the TXNRD1 gene, is an important enzyme involved in oxidant challenge. TXNRD1 plays a key role in regulating cell growth and transformation, and protects cells against oxidative damage. We investigated the association between TXNRD1 polymorphisms and ATDH susceptibility. In this prospective study, 280 newly diagnosed TB patients were followed-up for 3 months after beginning anti-TB therapy. Tag single-nucleotide polymorphisms (tag-SNPs) of TXNRD1 were selected using Haploview 4.2 based on the HapMap database of the Chinese Han in Beijing (CHB) panel. Genotyping was performed using the MassARRAY platform. Of the 280 patients enrolled in this study, 33 were lost to follow-up, 24 had ATDH, and 223 were free from ATDH. After adjusting for sex, age, smoking status, and body mass index, there were no significant differences in the allele and genotype frequency distributions of TXNRD1 SNPs between the ATDH and non-ATDH groups (all P > 0.05). The haplotype analysis showed that haplotype TCAGCC was associated with an increased risk of ATDH susceptibility [P = 0.024, OR (95%CI) = 6.273 (1.023-38.485)]. Further stratified analyses showed that the haplotype TCAGCC was associated with ATDH susceptibility in female subjects [P = 0.036, OR (95%CI) = 5.711 (0.917-35.560)] and non-smokers [P = 0.029, OR (95%CI) = 6.008 (0.971-37.158)]. Our results suggest that TXNRD1 variants may favor ATDH susceptibility in females and non-smokers. Further studies are required to verify this association.

A comparative study of efficacy and safety of febuxostat and allopurinol in pyrazinamide-induced hyperuricemic tubercular patients.

OBJECTIVES: To compare the efficacy and safety of febuxostat and allopurinol in pyrazinamide (PZA)-induced hyperuricemia in patients taking antitubercular therapy (ATT). METHODS: This randomized controlled study was conducted at a tertiary care teaching institute of Rajasthan in all the sputum-positive tubercular patients aged between 18 and 65 years of either sex. Serum uric acid level was monitored at 0th, 2nd, 4th, 6th, and 8th week of ATT. Patients whose uric acid level was found to be increased at 2nd week were finally recruited in the study. Ninety patients who developed hyperuricemia due to ATT were divided randomly into three groups (Group A - febuxostat, Group B - allopurinol, and Group C - control) of thirty patients each. Mean serum uric acid levels were calculated at all the weeks in all the groups, and serum uric acid levels were compared by applying student's t-test and ANOVA. RESULTS: Mean serum uric acid level decreased from 10.698 mg/dl (at 2nd week) to 7.846 mg/dl (at 8th week) in Group A and from 11.34 mg/dl (at 2nd week) to 7.280 mg/dl (at 8th week) in Group B. Numbers of adverse events encountered across both the treatment groups were same with both the drugs. CONCLUSION: Allopurinol and febuxostat were equally efficacious in lowering PZA induced raised serum uric acid level in tubercular patients, and it was possible to continue ATT without withdrawing PZA.

Liver Fatty Acid Binding Protein Deficiency Provokes Oxidative Stress, Inflammation, and Apoptosis-Mediated Hepatotoxicity Induced by Pyrazinamide in Zebrafish Larvae.

Pyrazinamide (PZA) is an essential antitubercular drug, but little is still known about its hepatotoxicity potential. This study examined the effects of PZA exposure on zebrafish (Danio rerio) larvae and the mechanisms underlying its hepatotoxicity. A transgenic line of zebrafish larvae that expressed enhanced green fluorescent protein (EGFP) in the liver was incubated with 1, 2.5, and 5 mM PZA from 72 h postfertilization (hpf). Different endpoints such as mortality, morphology changes in the size and shape of the liver, histological changes, transaminase analysis and apoptosis, markers of oxidative and genetic damage, as well as the expression of certain genes were selected to evaluate PZA-induced hepatotoxicity. Our results confirm the manner of PZA dose-dependent hepatotoxicity. PZA was found to induce marked injury in zebrafish larvae, such as liver atrophy, elevations of transaminase levels, oxidative stress, and hepatocyte apoptosis. To further understand the mechanism behind PZA-induced hepatotoxicity, changes in gene expression levels in zebrafish larvae exposed to PZA for 72 h postexposure (hpe) were determined. The results of this study demonstrated that PZA decreased the expression levels of liver fatty acid binding protein (L-FABP) and its target gene, peroxisome proliferator-activated receptor α (PPAR-α), and provoked more severe oxidative stress and hepatitis via the upregulation of inflammatory cytokines such as tumor necrosis factor alpha (TNF-α) and transforming growth factor ß (TGF-ß). These findings suggest that L-FABP-mediated PPAR-α downregulation appears to be a hepatotoxic response resulting from zebrafish larva liver cell apoptosis, and L-FABP can be used as a biomarker for the early detection of PZA-induced liver damage in zebrafish larvae.

Ameliorative Effects of Kolaviron, a Biflavonoid Fraction from Garcinia Kola Seed, on Hepato-renal Toxicity of Anti-tuberculosis Drugs in Wistar Rats.

BACKGROUND: Tuberculosis (TB) is an infectious disease of international health priority. The combination of anti-TB drugs (4-Tabs)- isoniazid (INH), rifampicin (RIF), pyrazinamide (PZA) and ethambutol (ETB) are effective in the management of the disease, however, their toxic effect is a major concern. PURPOSE: The study was designed to evaluate the toxicity of anti-TB drugs in male Wistar rats and possible ameliorative effects of kolaviron (KV), a biflavonoid from Garcinia kola seeds. METHODS: Twenty-eight rats were assigned into four groups; Group 1 (Control) received corn oil, Group 2 (4-Tabs) received therapeutic doses of INH (5 mg/kg), RIF (10 mg/kg), PZA (15 mg/kg) and ETB (15 mg/kg) in combination, Group 3 (4-Tabs + KV) received INH, RIF, PZA, ETB and KV (200 mg/kg) and Group 4 (KV) received KV (200 mg/kg) by oral gavage three times per week for 8 consecutive weeks. RESULTS: Administration of 4-Tabs caused oxidative stress resulting in significant (p = 0.031, 0.027) increase in malondialdehyde levels in the liver and kidney of rats by 101% and 34%, respectively. Also, 4-Tabs caused significant (p = 0.023-0.035) elevation of serum alanine and aspartate aminotransferases by 41% and 48%, creatinine by 252% and total bilirubin by 89%, respectively. In contrast, hepatic and renal antioxidant indices- reduced glutathione, glutathione peroxidase, glutathione-s-transferase and superoxide dismutase were significantly (p = 0.028-0.039) decreased in 4-Tabs-treated rats. Co-administration of KV with 4-Tabs significantly restored the antioxidant parameters and biochemical indices to near normal. CONCLUSION: These findings suggest that anti-TB drugs elicit oxidative damage in liver and kidney of rats while KV protects against the adverse effects via antioxidative mechanism.

First line anti-tuberculosis induced hepatotoxicity: incidence and risk factors.

In our days, tuberculosis, whet ever its localization, became a curable disease. The cornerstone is a 6 month course of isoniazid, rifampicine and pyrazinamide. All of the three first line antituberculosis drugs may induce hepatic damage which may have negative consequences for treatment outcome. Several risk factors were associated with the development of antituberculosis- drug-induced hepatotoxicity (ATDH). A retrospective study was conducted from July 2014 to March 2015 regarding all therapeutic drug-monitoring requests sent to the Laboratory of Poison Control and Pharmacovigilance Centre of Morocco. 142 patients diagnosed with active tuberculosis were included in study. Plasma peak levels of isoniazid, rifampicin and pyrazinamide were analyzed in plasma samples after 2 to 3 hours of administration of anti-tuberculosis treatment. Logistic regression was used to identify the ATDH risk factors. The incidence of ATDH was found 24.6% (35 patients out of 142). Intergroup differences in the plasma levels were statistically significant for isoniazid (p=0.036). ATDH was found to be associated with combined form of anti-TB drugs (p=0.002, COR=13.1, AOR= 13.5) and plasma concentration of INH superior to 2mg/l (p=0.045, COR=1.3, AOR= 1.4).age, gender, alcohol intake and smoking status were not significantly associated with ATDH. The finding of 24.6% incidence of hepatotoxicity is extremely high. Many factors can be associated with the development of ATDH such as genetic factors, combined forms of treatment and plasma peak levels.

Is Hyperuricemia Overlooked when Treating Pediatric Tuberculosis Patients with Pyrazinamide?

The treatment of tuberculosis (TB) requires long-term multiple drug use. Hyperuricemia is frequently reported in adults, but there are few data for the pediatric population. This study aimed to review drug-related side effects in pediatric patients that received treatment for TB. Patients with active TB undergoing treatment were followed for drug-related side effects. During the 7 year period, 23 patients with a mean age of 7.9 ± 4.66 years were treated. Drug-related side effects were observed in 14 patients. Hyperuricemia occurred in 12 of the 14 patients, vs. hepatotoxicity in 2. In all, eight of the patients with hyperuricemia had ≥2 episodes during pyrazinamide (PZA) therapy. Based on these findings, we devised an algorithm that could be used for the management of hyperuricemia in patients receiving PZA because of TB, and recommend that hyperuricemia be closely monitored during PZA therapy.

Pyridoxine induced rosacea-like dermatitis.

Rosacea is a common chronic inflammatory cutaneous disease of unknown etiology, characterized by remissions and exacerbations, presenting with centrofacial erythema and telangiectasias. It affects mainly adults around the age of 30 years and classically predominates in females. The pathophysiology of rosacea has not yet been fully understood. Risk factors are positive family history, very light skin phototype, sun exposure and consumption of spicy food or alcohol. Recently, there has been some evidence that some drugs or vitamins could be potential factors that can aggravate rosacea or induce rosacea-like symptoms. In this context, we present a 53-year-old female developing rosacea-like dermatitis due to a fixed combination of isoniazid and pyridoxine, which she was receiving along with rifampicin for the treatment of pulmonary tuberculosis.

Paradoxical increase in uric acid level with allopurinol use in pyrazinamide-induced hyperuricaemia.

We report the case of a 36-year-old man with psoriatic arthritis and miliary tuberculosis, whose serum uric acid (SUA) level increased after the initiation of antituberculosis treatment, which included pyrazinamide. Most strikingly and paradoxically, the patient's SUA level increased after treatment with allopurinol. On cessation of allopurinol, his SUA level decreased substantially, and complete normalisation was observed following the discontinuation of pyrazinamide treatment.

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.

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%).

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%).

A novel mechanism underlies the hepatotoxicity of pyrazinamide.

Relatively little is known about the hepatotoxicity of pyrazinamide (PZA). PZA requires activation by amidase to form pyrazinoic acid (PA). Xanthine oxidase then hydroxylates PA to form 5-hydroxypyrazinoic acid (5-OH-PA). PZA can also be directly oxidized to form 5-OH-PZA. Before this study, it was unclear which metabolic pathway or PZA metabolites led to hepatotoxicity. This study determines whether PZA metabolites are responsible for PZA-induced hepatotoxicity. PZA metabolites were identified and cytotoxicity in HepG2 cells was assessed. Potential PZA and PA hepatotoxicity was then tested in rats. Urine specimens were collected from 153 tuberculosis (TB) patients, and the results were evaluated to confirm whether a correlation existed between PZA metabolite concentrations and hepatotoxicity. This led to the hypothesis that coadministration of amidase inhibitor (bis-p-nitrophenyl phosphate [BNPP]) decreases or prevents PZA- and PZA metabolite-induced hepatotoxicity in rats. PA and 5-OH-PA are more toxic than PZA. Electron microscopy showed that PZA and PA treatment of rats significantly increases aspartate transaminase (AST) and alanine aminotransferase (ALT) activity and galactose single-point (GSP) levels (P < 0.005). PA and 5-OH-PA levels are also significantly correlated with hepatotoxicity in the urine of TB patients (P < 0.005). Amidase inhibitor, BNPP, decreases PZA-induced, but not PA-induced, hepatotoxicity. This is the first report of a cell line, animal, and clinical trial confirming that the metabolite 5-OH-PA is responsible for PZA-induced hepatotoxicity.

Gene expression profiling reveals potential key pathways involved in pyrazinamide-mediated hepatotoxicity in Wistar rats.

Pyrazinamide (PZA) is an important sterilizing prodrug that shortens the duration of tuberculosis therapy. However, hepatotoxicity has been reported during clinical trials investigating PZA. To determine the hepatotoxic effects of PZA in vivo and to further investigate the underlying cellular mechanism, we profiled the gene expression patterns of PZA-treated rat livers by microarray analysis. Wistar rats of both sexes were orally administered PZA at doses of 0.5, 1.0 and 2.0 g kg(-1) for 28 days. Body weight, absolute and relative liver weight, biochemical analysis, histopathology, oxidative stress parameters in liver homogenates and changes in global transcriptomic expression were evaluated to study the hepatotoxic effects of PZA. Our results confirm the dose-dependent and sex-related hepatotoxicity of PZA. Female rats were more sensitive to PZA-induced hepatotoxicity than males. Furthermore, changes in the activity of major antioxidant enzymes and nonenzymatic antioxidants (superoxide dismutase, total antioxidant capacity, glutathione and malondialdehyde), indicating the development of oxidative stress, were more significant in the PZA-treated group. PZA-induced gene expression changes were related to pathways involved in drug metabolism, peroxisome proliferator-activated receptor (PPAR) signaling, oxidative stress and apoptosis. Real-time polymerase chain reaction confirmed the regulation of selected genes involved in PZA-hepatotoxicity (Ephx1, Cyp2b1, Gstm1, Gstp1, Fabp7, Acaa1, Cpt-1b, Cyp8b1, Hmox1 and Ntrk1). We observed for the first time that these genes have effects on PZA-induced hepatotoxicity. In addition, drug metabolism and PPAR signaling pathways may play an important role in PZA hepatotoxicity. Taken together, these findings will be useful for future PZA hepatotoxicity studies.

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.

Management of and risk factors related to hepatotoxicity during tuberculosis treatment.

INTRODUCTION: Hepatotoxicity is one of the most frequent adverse events occurring during tuberculosis treatment that may negatively affect treatment compliance, clinical outcome. This study was designed to evaluate management, risk factors related to hepatotoxicity during tuberculosis treatment. PATIENTS AND METHODS: Hospitalized patients for tuberculosis treatment at Sureyyapasa Chest Diseases, and Chest Surgery Training and Research Hospital were included, between January 2004 and December 2007. Prevalence of hepatotoxicity, risk factors were evaluated among tuberculosis patients under anti-tuberculosis treatment according to World Health Organization (WHO) guideline. Hepatotoxicity was defined any elevated liver function tests with accompanying symptoms. Age, gender, past history of anti-tuberculosis treatment, extensity of radiological findings, co-morbid disorders and drug resistance were the risk factors evaluated in terms of development and recurrence of hepatotoxicity. RESULTS: Of 1443 patients (38.37 ± 16.74 years; 64.5% were males), 106 (7.3%) was identified to develop hepatotoxicity on an average of 20 days after beginning treatment and lasting an average of 14 days. Hepatotoxicity for once in 78.3% (n= 83) of patients and more than once in 21.7% (n= 23) patients. All anti-tuberculosis drugs was continued at full dosage after the normalization of liver enzyme in 76.4% (n= 81). In recurrence a step-by-step treatment was re-started by exclusion of responsible drug/s. Treatment was administered without modification of WHO regimes in 79.2%. Pyrazinamide was omitted in 15 cases while rifampicin only in one patient. Triple drug regimen with isoniazid, ethambutol and streptomycin was used in six cases. Quinolon was added to treatment only in one patient. Presence of a co-morbidity was determined to be significant predictor of hepatotoxicity development OR= 3.093 (CI= 1.95-4.89; p= 0.000) past history of anti-tuberculosis treatment was significantly associated with recurrence (p= 0.027). There was no hepatotoxicity dependent mortality. CONCLUSION: Hepatotoxicity can be successfully management of hepatotoxicity without second line tuberculosis drugs in ongoing treatment regime.