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1.
JAMA ; 331(21): 1814-1823, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38722621

RESUMO

Importance: In newly diagnosed Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL), disease progression due to acquired resistance to first- or second-generation BCR::ABL1 tyrosine kinase inhibitors is common. Ponatinib inhibits BCR::ABL1 and all single-mutation variants, including T315I. Objective: To compare frontline ponatinib vs imatinib in adults with newly diagnosed Ph+ ALL. Design, Setting, and Participants: Global registrational, phase 3, open-label trial in adults aged 18 years or older with newly diagnosed Ph+ ALL. From January 2019 to May 2022, eligible patients at 77 sites were randomized 2:1 to ponatinib (30 mg/d) or imatinib (600 mg/d) with reduced-intensity chemotherapy, followed by single-agent ponatinib or imatinib after the cycle 20 phase of the trial. The last date of follow-up for this analysis was August 12, 2022. Intervention: Patients received ponatinib, 30 mg/d, or imatinib, 600 mg/d, with reduced-intensity chemotherapy, followed by single-agent ponatinib or imatinib after cycle 20. The ponatinib dose was reduced to 15 mg on achievement of minimal residual disease-(MRD) negative complete remission. Main Outcomes and Measures: The primary end point of this interim analysis was MRD-negative complete remission (≤0.01% BCR::ABL1 [MR4] centrally assessed by reverse transcriptase-quantitative polymerase chain reaction), with complete remission maintained for at least 4 weeks at the end of cycle 3. The key secondary end point was event-free survival. Results: Of 245 patients randomized (median age, 54 years; 133 [54.3%] female), 232 (ponatinib, n = 154; imatinib, n = 78) who had p190 or p210 dominant isoforms verified by the central laboratory were analyzed for the primary end point. The MRD-negative complete remission rate (primary end point) was significantly higher with ponatinib (34.4% [53/154]) vs imatinib (16.7% [13/78]) (risk difference, 0.18 [95% CI, 0.06-0.29]; P = .002). At the data cutoff, event-free survival had not met the prespecified number of events. Median event-free survival was not reached in the ponatinib group and was 29 months in the imatinib group. The most common adverse events were similar between treatment groups. Arterial occlusive events were infrequent and comparable between groups (ponatinib, 2.5%; imatinib, 1.2%). Conclusions and Relevance: Ponatinib demonstrated a superior rate of MRD-negative complete remission at the end of induction vs imatinib when combined with reduced-intensity chemotherapy in adults with newly diagnosed Ph+ ALL. The safety profile of ponatinib was comparable with imatinib. Trial Registration: ClinicalTrials.gov Identifier: NCT03589326.


Assuntos
Antineoplásicos , Mesilato de Imatinib , Imidazóis , Leucemia-Linfoma Linfoblástico de Células Precursoras , Piridazinas , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Antineoplásicos/uso terapêutico , Antineoplásicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Proteínas de Fusão bcr-abl/genética , Mesilato de Imatinib/uso terapêutico , Mesilato de Imatinib/efeitos adversos , Imidazóis/uso terapêutico , Imidazóis/efeitos adversos , Imidazóis/administração & dosagem , Cromossomo Filadélfia , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Intervalo Livre de Progressão , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/efeitos adversos , Piridazinas/uso terapêutico , Piridazinas/efeitos adversos , Indução de Remissão , Adolescente
2.
Am J Med Open ; 92023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38835731

RESUMO

Background: Patients admitted with pneumonia and heart failure (HF) have increased mortality and cost compared to those without HF, but it is not known whether outcomes differ between systolic and diastolic HF. Management of concomitant pneumonia and HF is complicated because HF treatments can worsen complications of pneumonia. Methods: This is a retrospective cohort study from the Premier Database among patients admitted with pneumonia between 2010-2015. Patients were categorized based on systolic, diastolic, and combined HF using ICD-9 codes. The primary outcome was in-hospital mortality. Secondary outcomes included use of HF medications, length of stay, cost, intensive care unit (ICU) admission, as well as use of invasive mechanical ventilation (IMV), vasopressors and inotropes. Multivariable logistic regression was used to describe associations of these outcomes with type of HF. Results: Of 123,211 patients with pneumonia and HF, 41,196 (33.4%) had systolic HF, 69,982 (56.8%) diastolic HF, and 12,033 (9.8%) had combined HF. Compared to patients with diastolic HF, after multivariable adjustment systolic HF was associated with higher in-hospital mortality (OR 1.15; 95% CI:1.11-1.20), ICU admission, and use of IMV and vasoactive agents, but not with increased length of stay or cost. Among patients with systolic HF, 80% received a loop diuretic, 72% a beta blocker, 48% angiotensin converting enzyme inhibitor or angiotensin receptor blocker, and 12.5% a mineralocorticoid receptor antagonist. Conclusion: Systolic HF is associated with added risk in pneumonia compared to diastolic HF. There may also be an opportunity to optimize medications in systolic HF prior to discharge.

3.
Int J Pharm Pract ; 30(4): 398-400, 2022 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-35652466

RESUMO

OBJECTIVE: The objective of this study is to validate the glycaemic safety of a simple insulin protocol using weight-based insulin rates adapted from American guidance for the management of adult diabetic ketoacidosis. METHODS: Measures of hypoglycaemia were retrospectively assessed in a single cohort of inpatient adults. The primary outcome was incidence of hypoglycaemia during insulin infusion. KEY FINDINGS: Hypoglycaemia during infusion occurred in 6/81 patients (7% [95% CI 3-16%]). Five of these occurrences were associated with protocol nonadherence. CONCLUSIONS: The glycaemic safety of a novel, variable-rate insulin protocol directly incorporating weight-based infusion rates is supported by this single-centre study.


Assuntos
Diabetes Mellitus Tipo 1 , Cetoacidose Diabética , Hipoglicemia , Adulto , Glicemia , Diabetes Mellitus Tipo 1/complicações , Humanos , Hipoglicemia/induzido quimicamente , Hipoglicemia/epidemiologia , Hipoglicemiantes/efeitos adversos , Incidência , Insulina/efeitos adversos , Estudos Retrospectivos
5.
Am J Med Open ; 7: 100013, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35734378

RESUMO

Background: Among patients admitted for pneumonia, heart failure (HF) is associated with worse outcomes. It is unclear whether this association is due to acute HF exacerbations, complex medical management, or chronic co-morbid conditions. Methods: This is a retrospective cohort study of patients admitted between July 2010 and June 2015 at 651 US hospitals with a principal diagnosis of either pneumonia or secondary diagnosis of pneumonia with a primary diagnosis of respiratory failure or sepsis. Comorbidities were identified by ICD-9 codes and medical management by daily charge codes. Patients were categorized according to the presence and acuity of admission diagnosis of HF. In-hospital mortality was the primary outcome. Secondary outcomes included length of stay, hospital cost, ICU admission, use of mechanical ventilation, vasopressors and inotropes. Logistic regression was used to study the association of outcomes with presence and acuity of HF. Results: Of 783,702 patients who met inclusion criteria, 212,203 (27%) had a diagnosis of HF. Of these, 56,306 (26.5%) had acute while 48,188 (22.7%) had chronic HF on admission; 51% had a diagnosis of unspecified HF. In multivariable-adjusted models, having any HF was associated with increased mortality (OR 1.35 [1.33 - 1.38]) compared to those without HF; increased mortality was associated with acute HF (OR 1.19 [1.15 - 1.22]) but not chronic HF (OR 0.92 [0.89 - 0.96]). Conclusion: The worse outcomes for pneumonia patients with HF appear due to acute HF exacerbations. Adjustment for HF without accounting for chronicity could lead to biased prognostic and billing estimates.

6.
Cardiovasc Drugs Ther ; 36(2): 309-322, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-33599896

RESUMO

PURPOSE: Between 2012 and 2017, the FDA approved 29 therapies for a cardiovascular disease (CVD) indication. Due to the limited literature on patient safety outcomes for recently approved CVD medications, this study investigated adverse drug reports (ADRs) reported in the FDA Adverse Event Reporting System (FAERS). METHODS: A disproportionality analysis of spontaneously reported ADR was conducted. Reports in FAERS from Quarter 1, 2012, through Quarter 1, 2019, were compiled, allowing a 2-year buffer following drug approval in 2017. Top 10 reported ADRs and reporting odds ratios (ROR; confidence interval (CI)), a measure of disproportionality, were analyzed and compared to drugs available prior to 2012 as appropriate. RESULTS: Of 7,952,147 ADR reports, 95,016 (1.19%) consisted of reports for newly approved CVD medications. For oral anticoagulants, apixaban had significantly lower reports for anemia and renal failure compared to dabigatran and rivaroxaban but greater reports for neurological signs/symptoms, and arrhythmias. Evaluating heart failure drugs, sacubitril/valsartan had greater reports for acute kidney injury, coughing, potassium imbalances, and renal impairment but notably, lower for angioedema compared to lisinopril. Assessing familial hypercholesterolemia drugs, alirocumab had greater reports for joint-related-signs/symptoms compared to other agents in this category. A newer pulmonary arterial hypertension treatment, selexipag, had greater reports of reporting for bone/joint-related-signs/symptoms but riociguat had greater reports for hemorrhages and vascular hypotension. CONCLUSION: Pharmacovigilance studies allow an essential opportunity to evaluate the safety profile of CVD medications in clinical practice. Additional research is needed to evaluate these reported safety concerns for recently approved CVD medications.


Assuntos
Fármacos Cardiovasculares , Doenças Cardiovasculares , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Sistemas de Notificação de Reações Adversas a Medicamentos , Aminobutiratos , Arritmias Cardíacas , Compostos de Bifenilo , Fármacos Cardiovasculares/efeitos adversos , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/epidemiologia , Bases de Dados Factuais , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/diagnóstico , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Humanos , Farmacovigilância , Estados Unidos/epidemiologia , United States Food and Drug Administration
7.
Thromb Update ; 2: 100027, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-38620459

RESUMO

Background: COVID-19 is associated with hypercoagulability and increased incidence of thrombosis. We compared the clinical outcomes of adults hospitalized with COVID-19 who were on therapeutic anticoagulants to those on prophylactic anticoagulation. Materials and methods: We performed an observational study of adult inpatients' with COVID-19 from March 9 to June 26, 2020. We compared patients who were continued on their outpatient prescribed therapeutic anticoagulation and those who were newly started on therapeutic anticoagulation for COVID-19 (without other indication) to those who were on prophylactic doses. The primary outcome was overall death while secondary outcomes were critical illness (World Health Organization Ordinal Scale for Clinical Improvement score ≥5), mechanical ventilation, and death among patients who first had critical illness. We adjusted for age, sex, race, body mass index (BMI), Charlson score, glucose on admission, and use of antiplatelet agents. Results: Of 1716 inpatients with COVID-19, 171 patients were continued on their therapeutic anticoagulation and 78 were started on new therapeutic anticoagulation for COVID-19. In patients continued on home therapeutic anticoagulation, there were no differences in overall death, critical illness, mechanical ventilation, or death among patients with critical illness compared to patients on prophylactic anticoagulation. In patients receiving new therapeutic anticoagulation for COVID-19, there was increased death (OR 5.93; 95% CI 3.71-9.47), critical illness (OR 14.51; 95% CI 7.43-28.31), need mechanical ventilation (OR 11.22; 95% CI 6.67-18.86), and death after first having critical illness (OR 5.51; 95% CI 2.80-10.87). Conclusions: Therapeutic anticoagulation for inpatients with COVID-19 was not associated with improved outcomes.

8.
J Autoimmun ; 114: 102514, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32768244

RESUMO

Immune checkpoint inhibitors (ICIs) have shown significant efficacy in patients with various malignancies, however, they are associated with a wide range of immune-related toxicities affecting many organs, including the liver. Immune-mediated liver injury caused by checkpoint inhibitors (ILICI) is a distinctive form of drug induced liver injury (DILI), that differs from most DILI types in presumed underlying mechanism, incidence, and response to therapeutic interventions. Despite increased awareness of ILICI and other immune-related adverse effects of ICIs reflected by recent guidelines for their management in post marketing clinical practice, there is lack of uniform best practices to address ILICI risk during drug development. As efforts to develop safer and more effective ICIs for additional indications grow, and as combination therapies including ICIs are increasingly investigated, there is a growing need for consistent practices for ILICI in drug development. This publication summarizes current best practices to optimize the monitoring, diagnosis, assessment, and management of suspected ILICI in clinical trials using ICI as a single agent and in combination with other ICIs or other oncological agents. It is one of several publications developed by the IQ DILI Initiative in collaboration with DILI experts from academia and regulatory agencies. Recommended best practices are outlined pertaining to hepatic inclusion and exclusion criteria, monitoring of liver tests, ILICI detection, approach to a suspected ILICI signal, causality assessment, hepatic discontinuation rules and additional medical treatment.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Suscetibilidade a Doenças , Inibidores de Checkpoint Imunológico/efeitos adversos , Animais , Gerenciamento Clínico , Desenvolvimento de Medicamentos , Humanos , Inibidores de Checkpoint Imunológico/uso terapêutico , Testes de Função Hepática , Neoplasias/complicações , Neoplasias/tratamento farmacológico
9.
Dis Model Mech ; 12(7)2019 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-31300413

RESUMO

Cleft palate is a common birth defect, occurring in approximately 1 in 1000 live births worldwide. Known etiological mechanisms of cleft palate include defects within developing palate shelf tissues, defects in mandibular growth and defects in spontaneous fetal mouth movement. Until now, experimental studies directly documenting fetal mouth immobility as an underlying cause of cleft palate have been limited to models lacking neurotransmission. This study extends the range of anomalies directly demonstrated to have fetal mouth movement defects correlated with cleft palate. Here, we show that mouse embryos deficient in retinoic acid (RA) have mispatterned pharyngeal nerves and skeletal elements that block spontaneous fetal mouth movement in utero Using X-ray microtomography, in utero ultrasound video, ex vivo culture and tissue staining, we demonstrate that proper retinoid signaling and pharyngeal patterning are crucial for the fetal mouth movement needed for palate formation. Embryos with deficient retinoid signaling were generated by stage-specific inactivation of retinol dehydrogenase 10 (Rdh10), a gene crucial for the production of RA during embryogenesis. The finding that cleft palate in retinoid deficiency results from a lack of fetal mouth movement might help elucidate cleft palate etiology and improve early diagnosis in human disorders involving defects of pharyngeal development.


Assuntos
Oxirredutases do Álcool/fisiologia , Boca/embriologia , Palato/embriologia , Animais , Fissura Palatina/etiologia , Fissura Palatina/fisiopatologia , Modelos Animais de Doenças , Camundongos , Boca/fisiologia , Movimento , Retinoides/deficiência
10.
11.
Respir Care ; 58(6): 990-1007, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23709196

RESUMO

Ventilator-associated pneumonia (VAP) is one of the most frequent hospital-acquired infections occurring in intubated patients. Because VAP is associated with higher mortality, morbidity, and costs, there is a need to solicit further research for effective preventive measures. VAP has been proposed as an indicator of quality of care. Clinical diagnosis has been criticized to have poor accuracy and reliability. Thus, the Centers for Disease Control and Prevention has introduced a new definition based upon objective and recordable data. Institutions are nowadays reporting a VAP zero rate in surveillance programs, which is in discrepancy with clinical data. This reduction has been highlighted in epidemiological studies, but it can only be attributed to a difference in patient selection, since no additional intervention has been taken to modify pathogenic mechanisms in these studies. The principal determinant of VAP development is the presence of the endotracheal tube (ETT). Contaminated oropharyngeal secretions pool over the ETT cuff and subsequently leak down to the lungs through a hydrostatic gradient. Impairment of mucociliary motility and cough reflex cannot counterbalance with a proper clearance of secretions. Lastly, biofilm develops on the inner ETT surface and acts as a reservoir for microorganism inoculum to the lungs. New preventive strategies are focused on the improvement of secretions drainage and prevention of bacterial colonization. The influence of gravity on mucus flow and body positioning can facilitate the clearance of distal airways, with decreased colonization of the respiratory tract. A different approach proposes ETT modifications to limit the leakage of oropharyngeal secretions: subglottic secretion drainage and cuffs innovations have been addressed to reduce VAP incidence. Moreover, coated-ETTs have been shown to prevent biofilm formation, although there is evidence that ETT clearance devices (Mucus Shaver) are required to preserve the antimicrobial properties over time. Here, after reviewing the most noteworthy issues in VAP definition and pathophysiology, we will present the more interesting proposals for VAP prevention.


Assuntos
Biofilmes , Intubação Intratraqueal/efeitos adversos , Pneumonia Associada à Ventilação Mecânica/etiologia , Pneumonia Associada à Ventilação Mecânica/prevenção & controle , Respiração Artificial/efeitos adversos , Drenagem , Desenho de Equipamento , Humanos , Intubação Intratraqueal/instrumentação , Posicionamento do Paciente , Pneumonia Associada à Ventilação Mecânica/diagnóstico , Pneumonia Associada à Ventilação Mecânica/microbiologia
12.
J Appl Toxicol ; 32(2): 108-17, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21337588

RESUMO

Glitazones, used for type II diabetes, have been associated with liver damage in humans. A structural feature known as a 2,4-thiazolidinedione (TZD) ring may contribute to this toxicity. TZD rings are of interest since continued human exposure via the glitazones and various prototype drugs is possible. Previously, we found that 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT) was hepatotoxic in rats. To evaluate the importance of structure on DCPT toxicity, we therefore studied two series of analogs. The TZD ring was replaced with: a mercaptoacetic acid group {[[[(3,5-dichlorophenyl)amino]carbonyl]thio]acetic acid, DCTA}; a methylated TZD ring [3-(3,5-dichlorophenyl)-5-methyl-2,4-thiazolidinedione, DPMT]; and isomeric thiazolidinone rings [3-(3,5-dichlorophenyl)-2- and 3-(3,5-dichlorophenyl)-4-thiazolidinone, 2-DCTD and 4-DCTD, respectively]. The following phenyl ring-modified analogs were also tested: 3-phenyl-, 3-(4-chlorophenyl)-, 3-(3,5-dimethylphenyl)- and 3-[3,5-bis(trifluoromethyl)phenyl]-2,4-thiazolidinedione (PTZD, CPTD, DMPT and DFMPT, respectively). Toxicity was assessed in male Fischer 344 rats 24 h after administration of the compounds. In the TZD series only DPMT produced liver damage, as evidenced by elevated serum alanine aminotransferase (ALT) activities at 0.6 and 1.0 mmol kg(-1) (298.6 ± 176.1 and 327.3 ± 102.9 Sigma-Frankel units ml(-1) , respectively) vs corn oil controls (36.0 ± 11.3) and morphological changes in liver sections. Among the phenyl analogs, hepatotoxicity was observed in rats administered PTZD, CPTD and DMPT; with ALT values of 1196.2 ± 133.6, 1622.5 ± 218.5 and 2071.9 ± 217.8, respectively (1.0 mmol kg(-1) doses). Morphological examination revealed severe hepatic necrosis in these animals. Our results suggest that hepatotoxicity of these compounds is critically dependent on the presence of a TZD ring and also the phenyl substituents.


Assuntos
Hepatopatias/etiologia , Fígado/efeitos dos fármacos , Tiazolidinedionas/química , Tiazolidinedionas/toxicidade , Alanina Transaminase/metabolismo , Animais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/toxicidade , Hepatopatias/patologia , Masculino , Ratos , Ratos Endogâmicos F344 , Relação Estrutura-Atividade , Tiazolidinedionas/administração & dosagem , Tiazolidinedionas/uso terapêutico
13.
Toxicol In Vitro ; 25(8): 2113-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21964476

RESUMO

The thiazolidinedione (TZD) ring is a constituent of the glitazones that are used to treat type II diabetes. Liver injury has been reported following chronic glitazone use; however, they do not produce hepatic damage in common laboratory animal species. In contrast, 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT) causes hepatotoxicity in rats. DCPT toxicity is dependent upon the presence of an intact TZD ring and cytochrome P450 (CYP)-mediated biotransformation. To further investigate TZD ring-induced toxicity, DCPT and several structural analogues or potential metabolites were tested in vitro using wild type human hepatoma HepG2 and HepG2 cells stably transfected with the CYP3A4 isozyme. CYP3A4 activity was confirmed by measuring testosterone 6ß-hydroxylation. Both cell lines were treated with 0-250 µM of the compounds in Hanks' balanced salt solution. Cell viability was measured after 24 h. DCPT and S-(3,5-dichlorophenyl)aminocarbonyl thioglycolic acid (DCTA) were the most toxic compounds of the series. Furthermore, DCPT was significantly more toxic in transfected cells (LC50=160.2±5.9 µM) than in wild type cells (LC50=233.0±19.7 µM). Treatment with a CYP3A4 inhibitor or inducer attenuated or potentiated DCPT cytotoxicity, respectively. These results suggest that DCPT-induced cytotoxicity in the transfected HepG2 cells is partially dependent on CYP3A4.


Assuntos
Citocromo P-450 CYP3A/metabolismo , Tiazolidinedionas/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Citocromo P-450 CYP3A/genética , Inibidores do Citocromo P-450 CYP3A , Dexametasona/farmacologia , Inibidores Enzimáticos/farmacologia , Células Hep G2 , Humanos , Hidrólise , Hipoglicemiantes/toxicidade , Cetoconazol/farmacologia , Esteroide Hidroxilases/metabolismo , Transfecção
14.
Pediatr Blood Cancer ; 55(3): 554-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20658630

RESUMO

The objective of this study is to determine the prevalence of adherence to daily medications among children with sickle cell disease (SCD). Prescription records for 12 months were obtained from participants who had insurance in a Medicaid-based single health maintenance organization. Adherence was measured as a ratio between the number of expected days and the observed days between two refill periods for daily medications. A total of 93 children were studied. The average refill prescription rate was 58.4%. More formal strategies are required to identify barriers to prescription refills among children with SCD.


Assuntos
Anemia Falciforme/tratamento farmacológico , Adesão à Medicação , Anemia Falciforme/complicações , Antiasmáticos/uso terapêutico , Antidrepanocíticos/uso terapêutico , Criança , Estudos de Coortes , Ácido Fólico/uso terapêutico , Hematínicos/uso terapêutico , Humanos , Hidroxiureia/uso terapêutico , Penicilinas/uso terapêutico
15.
Toxicology ; 250(2-3): 100-8, 2008 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-18621092

RESUMO

Cytochrome P450 (CYP)-mediated metabolism in the thiazolidinedione (TZD) ring may contribute to the hepatotoxicity of the insulin-sensitizing agents such as troglitazone. We were interested in determining if biotransformation could also be a factor in the liver damage associated with another TZD ring containing compound, 3-(3,5-dichlorophenyl)-2,4-thiazolidinedione (DCPT). Therefore, hepatotoxic doses of DCPT (0.6 or 1.0 mmol/kg, i.p.) were administered to male Fischer 344 rats after pretreatment with vehicle, 1-aminobenzotriazole (ABT, non-selective CYP inhibitor) and troleandomycin (TAO, CYP3A inhibitor). Alternatively, rats were pretreated with vehicle or the CYP3A inducer dexamethasone (DEX) prior to a non-toxic DCPT dose (0.2 mmol/kg, i.p.). Vehicle-, ABT-, TAO- and DEX-only control groups were also run. Toxicity was assessed 24 h after DCPT administration. Both hepatotoxic doses of DCPT induced elevations in serum alanine aminotransferase (ALT) levels that were attenuated by ABT or TAO pretreatment. Liver sections from rats that received vehicle+DCPT revealed areas of gross necrosis and neutrophil invasion, whereas sections from ABT+DCPT and TAO+DCPT rats showed minor changes compared to controls. DEX pretreatment potentiated ALT levels associated with the non-toxic DCPT dose. Furthermore, DEX+DCPT rat liver sections exhibited hepatic injury when compared against rats that received vehicle+DCPT. Blood urea nitrogen levels, urinalysis and kidney morphology were not markedly altered by any combination of pretreatments or treatments. Enzyme activity and Western blotting experiments with rat liver microsomes confirmed the effects of the various pretreatments. Our results suggest that hepatic CYP3A isozymes may be involved in DCPT-induced liver damage in male rats. We believe this is the first report demonstrating that modulation of the biotransformation of a TZD ring-containing compound can alter hepatotoxicity in a common animal model.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Fungicidas Industriais/farmacocinética , Fungicidas Industriais/toxicidade , Tiazolidinedionas/farmacocinética , Tiazolidinedionas/toxicidade , Animais , Biotransformação , Nitrogênio da Ureia Sanguínea , Western Blotting , Peso Corporal/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP2B1/metabolismo , Inibidores das Enzimas do Citocromo P-450 , Inibidores Enzimáticos/farmacologia , Hidroxilação , Indicadores e Reagentes , Masculino , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Testosterona/metabolismo
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