RESUMO
Iron overload from repeated transfusions has a negative impact on cardiac function, and iron chelation therapy may help prevent cardiac dysfunction in transfusion-dependent patients with myelodysplastic syndromes (MDS). TELESTO (NCT00940602) was a prospective, placebo-controlled, randomised study to evaluate the iron chelator deferasirox in patients with low- or intermediate-1-risk MDS and iron overload. Echocardiographic parameters were collected at screening and during treatment. Patients receiving deferasirox experienced a significant decrease in the composite risk of hospitalisation for congestive heart failure (CHF) or worsening of cardiac function (HR = 0.23; 95% CI: 0.05, 0.99; nominal p = 0.0322) versus placebo. No significant differences between the arms were found in left ventricular ejection fraction, ventricular diameter and mass or pulmonary artery pressure. The absolute number of events was low, but the enrolled patients were younger than average for patients with MDS, with no serious cardiac comorbidities and a modest cardiovascular risk profile. These results support the effectiveness of deferasirox in preventing cardiac damage caused by iron overload in this patient population. Identification of patients developing CHF is challenging due to the lack of distinctive echocardiographic features. The treatment of iron overload may be important to prevent cardiac dysfunction in these patients, even those with moderate CHF risk.
Assuntos
Deferasirox , Quelantes de Ferro , Sobrecarga de Ferro , Síndromes Mielodisplásicas , Humanos , Deferasirox/uso terapêutico , Síndromes Mielodisplásicas/terapia , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/complicações , Masculino , Feminino , Quelantes de Ferro/uso terapêutico , Pessoa de Meia-Idade , Idoso , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/tratamento farmacológico , Estudos Prospectivos , Benzoatos/uso terapêutico , Benzoatos/efeitos adversos , Insuficiência Cardíaca/etiologia , Reação Transfusional/etiologia , Ecocardiografia , Adulto , Idoso de 80 Anos ou mais , Triazóis/uso terapêutico , Triazóis/efeitos adversos , Transfusão de SangueRESUMO
Understanding consequences of poor chelation compliance is crucial given the enormous burden of post-transfusional iron overload complications. We systematically reviewed iron-chelation therapy (ICT) compliance, and the relationship between compliance with health outcome and health-related quality of life (HRQoL) in thalassaemia patients. Several reviewers performed systematic search strategy of literature through PubMed, Scopus, and EBSCOhost. The preferred reporting items of systematic reviews and meta-analyses (PRISMA) guidelines were followed. Of 4917 studies, 20 publications were included. The ICT compliance rate ranges from 20.93 to 75.3%. It also varied per agent, ranging from 48.84 to 85.1% for desferioxamine, 87.2-92.2% for deferiprone and 90-100% for deferasirox. Majority of studies (N = 10/11, 90.91%) demonstrated significantly negative correlation between compliance and serum ferritin, while numerous studies revealed poor ICT compliance linked with increased risk of liver disease (N = 4/7, 57.14%) and cardiac disease (N = 6/8, 75%), endocrinologic morbidity (N = 4/5, 90%), and lower HRQoL (N = 4/6, 66.67%). Inadequate compliance to ICT therapy is common. Higher compliance is correlated with lower serum ferritin, lower risk of complications, and higher HRQoL. These findings should be interpreted with caution given the few numbers of evidence.
Assuntos
Quelantes de Ferro , Talassemia , Humanos , Quelantes de Ferro/uso terapêutico , Deferasirox , Deferiprona , Desferroxamina/uso terapêutico , Qualidade de Vida , Piridonas/efeitos adversos , Benzoatos/efeitos adversos , Triazóis/efeitos adversos , Talassemia/tratamento farmacológico , Terapia por Quelação , Ferritinas , Avaliação de Resultados em Cuidados de SaúdeRESUMO
Plants used in traditional medicine in the management of epilepsy could potentially yield novel drug compounds with antiepileptic properties. The medicinal plant Securidaca longepedunculata is widely used in traditional medicine in the African continent, and epilepsy is among several indications. Limited knowledge is available on its toxicity and medicinal effects, such as anticonvulsant activities. This study explores the potential in vivo inhibition of seizure-like paroxysms and toxicity effects of dichloromethane (DCM) and ethanol (EtOH) extracts, as well as isolated xanthones and benzoates of S. longepedunculata. Ten phenolic compounds were isolated from the DCM extract. All of the substances were identified by nuclear magnetic resonance spectroscopy. Assays for toxicity and inhibition of pentylenetetrazole (PTZ)-induced seizure-like paroxysms were performed in zebrafish larvae. Among the compounds assessed in the assay for maximum tolerated concentration (MTC), benzyl-2-hydroxy-6-methoxy-benzoate (MTC 12.5 µM), 4,8-dihydroxy-1,2,3,5,6-pentamethoxyxanthone (MTC 25 µM), and 1,7-dihydroxy-4-methoxyxanthone (MTC 6.25 µM) were the most toxic. The DCM extract, 1,7-dihydroxy-4-methoxyxanthone and 2-hydroxy-1,7-dimethoxyxanthone displayed the most significant inhibition of paroxysms by altering the locomotor behavior in GABAA receptor antagonist, PTZ, which induced seizures in larval zebrafish. The EtOH extract, benzyl benzoate, and benzyl-2-hydroxy-6-methoxy-benzoate unexpectedly increased locomotor activity in treated larval zebrafish and decreased locomotor activity in nontreated larval zebrafish, seemingly due to paradoxical excitation. The results reveal promising medicinal activities of this plant, contributing to our understanding of its use as an antiepileptic drug. It also shows us the presence of potentially new lead compounds for future drug development.
Assuntos
Epilepsia , Securidaca , Animais , Peixe-Zebra , Securidaca/química , Convulsões/tratamento farmacológico , Anticonvulsivantes/farmacologia , Epilepsia/tratamento farmacológico , Extratos Vegetais/química , Pentilenotetrazol , Benzoatos/efeitos adversosRESUMO
Combination chelation therapies are considered in transfusion-dependent thalassemia patients for whom monotherapy regimens have failed to achieve iron balance or intensification of iron chelation therapy is required for the rapid reduction of excess iron to avoid permanent organ damage. Combination chelation may provide a more flexible approach for individualizing chelation therapy, thereby improving tolerability, adherence, and quality of life. In principle, iron chelators can be combined with an infinite number of dosing regimens; these involve simultaneous or sequential exposure to the chelators on the same day or alternating the drugs on different days. Clinical studies have established the safety and efficacy of chelation combinations. However, real-life data with combination therapies indicate the significance of compliance for a meaningful reduction in iron overload compared to monotherapies.
Assuntos
Terapia por Quelação , Sobrecarga de Ferro , Humanos , Deferasirox/uso terapêutico , Desferroxamina/uso terapêutico , Deferiprona/uso terapêutico , Qualidade de Vida , Benzoatos/efeitos adversos , Triazóis , Piridonas , Quelantes de Ferro/uso terapêutico , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/induzido quimicamente , Ferro , Quimioterapia CombinadaRESUMO
Iron chelation therapy (ICT) is the mainstay of treatment in patients with thalassemia requiring blood transfusions. This phase 2 JUPITER study evaluated patient preference between film-coated tablet (FCT) and dispersible tablet (DT) in transfusion-dependent thalassemia (TDT) or non-TDT (NTDT) patients treated with both formulations in a sequential manner. The primary endpoint was patient-reported preference for FCT over DT, while secondary outcomes included patient reported outcomes (PROs) evaluated by overall preference, and by age, thalassemia transfusion status, and previous ICT status. Out of 183 patients screened, 140 and 136 patients completed the treatment periods 1 and 2 of the core study, respectively. At week 48, the majority of patients preferred FCT over DT (90.3 vs. 7.5%; difference of percentage: 0.83 [95% confidence interval (CI), 0.75-0.89; P < 0.0001]). FCT scored better on secondary PROs and showed less severe gastrointestinal symptoms than DT, except in the change of modified Satisfaction with Iron Chelation Therapy (mSICT) preference scores, which were similar for both the formulations. Patients with TDT had stable ferritin levels, while it showed a downward trend up to week 48 in patients with NTDT on deferasirox treatment. Overall, 89.9% of patients reported ≥ 1 adverse event (AE), of which 20.3% experienced ≥ 1 serious AE. The most common treatment-emergent AEs were proteinuria, pyrexia, urine protein/creatinine ratio increase, diarrhea, upper respiratory tract infections, transaminase increase, and pharyngitis. Overall, this study reinforced the observations from the previous study by showing a distinct patient preference for FCT over DT formulation and further supported the potential benefits of life-long compliance with ICT.
Assuntos
Sobrecarga de Ferro , Talassemia , Humanos , Deferasirox , Sobrecarga de Ferro/complicações , Preferência do Paciente , Talassemia/tratamento farmacológico , Comprimidos , Ferro , Quelantes de Ferro/efeitos adversos , Benzoatos/efeitos adversosRESUMO
Drug-induced nephrolithiasis can arise from insoluble components within medications or crystallization of metabolites due to changes in metabolism and urinary pH. The connection between drugs utilized for iron chelation therapy (ICT) and nephrolithiasis is not well understood. In this report, we describe two pediatric patients diagnosed with nephrolithiasis while undergoing treatment with the chelating agents deferasirox, deferiprone, and deferoxamine for iron overload secondary to repeat blood transfusion.
Assuntos
Sobrecarga de Ferro , Nefrolitíase , Talassemia beta , Humanos , Criança , Terapia por Quelação/efeitos adversos , Quelantes de Ferro/efeitos adversos , Deferasirox/efeitos adversos , Deferiprona/uso terapêutico , Desferroxamina/efeitos adversos , Benzoatos/efeitos adversos , Triazóis , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Nefrolitíase/induzido quimicamente , Nefrolitíase/complicações , Nefrolitíase/tratamento farmacológico , Ferro/uso terapêutico , Talassemia beta/terapiaRESUMO
Background: Deferasirox has proved good efficacy and acceptable safety for the management of thalassaemia patients. However, some patients are unresponsive or intolerant to once-daily administration of deferasirox even at a high dose. The current study evaluated the effectiveness and tolerability of twice-daily dosing of deferasirox among transfusion-dependent paediatric beta-thalassaemia patients. Methods: This prospective randomized single-blinded parallel study included all transfusion-dependent paediatric beta-thalassaemia patients prescribed with deferasirox, who visit the study site for their regular blood transfusions and follow-up. The enrolled patients were randomized into intervention and control groups by using a simple block randomization method. In the intervention group, the once-daily dosing of deferasirox was changed to twice-daily dosing with the same total daily dose. Whereas, in the control group, the patients continued with the once-daily deferasirox dosing. The serum ferritin levels of both groups were determined on the enrolment day and after 6 months of follow-up. Results: Forty-one patients were included for analysis. A statistically significant mean decrease in serum ferritin levels was detected in the intervention group, while the serum ferritin levels of the control group significantly increased from baseline. The twice-daily dosing of deferasirox was better tolerated by the thalassaemia patients when compared to once-daily dosing. Conclusion: This study concludes that twice-daily dosing of deferasirox with the same total daily dose significantly enhances the iron chelation efficacy and tolerability among transfusion-dependent paediatric beta-thalassaemia patients when compared to once-daily regimen.
Assuntos
Sobrecarga de Ferro , Talassemia , Talassemia beta , Humanos , Criança , Deferasirox , Talassemia beta/tratamento farmacológico , Quelantes de Ferro/efeitos adversos , Estudos Prospectivos , Benzoatos/efeitos adversos , Triazóis/efeitos adversos , FerritinasRESUMO
WHAT IS KNOWN AND OBJECTIVE: Patients with low-risk myelodysplastic syndrome (MDS) and aplastic anaemia (AA) often need transfusions, which may accelerate iron overload. The aim of this study was to evaluate the efficacy, safety and dose-effect relationships of deferasirox (DFX) in patients with low-risk MDS and AA who were refractory to regular treatment in a real-world setting. METHODS: Patient data were recorded, and dose-effect relationships of DFX were calculated after the first 6 months. Total annual exposure to DFX was calculated after 12 months and expressed as the accumulated exposure time at a dosage of 20 mg/kg/day. RESULTS AND DISCUSSION: Sixty-one patients with low-risk MDS and 51 with AA were enrolled. The minimum dosage of DFX needed for a significant serum ferritin (SF) decrease was 20 mg/kg/day at 6 months, and the minimum accumulation of DFX had to reach 9 months at 20 mg/kg/day by 12 months for patients with low-risk MDS. For patients with AA, the minimum dosage was 10 mg/kg/day at 6 months, and the minimum accumulation had to reach 3 months at 20 mg/kg/day by 12 months. With the same exposure, significant improvements in haematological parameters were also observed in AA. Lower liver enzymes compared with baseline were observed. Gastrointestinal disorders and elevated serum creatinine were the most common side effects. Higher exposure to DFX correlated with longer overall survival (OS). WHAT IS NEW AND CONCLUSION: A significant decrease in SF and an improvement in haematologic parameters, organ function and even OS can be achieved if the accumulated DFX dose reaches a certain level. Patients with low-risk MDS need a higher dose than those with AA.
Assuntos
Anemia Aplástica , Sobrecarga de Ferro , Síndromes Mielodisplásicas , Anemia Aplástica/tratamento farmacológico , Benzoatos/efeitos adversos , Creatinina , Deferasirox/uso terapêutico , Ferritinas/uso terapêutico , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Síndromes Mielodisplásicas/tratamento farmacológico , Triazóis/efeitos adversosRESUMO
Eltrombopag (EPAG) has been approved for the treatment of aplastic anemia and for immune thrombocytopenia, and a subset of patients require long-term therapy. Due to polyvalent cation chelation, prolonged therapy leads to previously underappreciated iron depletion. We conducted a retrospective review of patients treated at the NIH for aplastic anemia, myelodysplastic syndrome, and unilineage cytopenias, comparing those treated with EPAG to a historical cohort treated with immunosuppression without EPAG. We examined iron parameters, duration of therapy, response assessment, relapse rates, and common demographic parameters. We included 521 subjects treated with (n = 315) or without EPAG (n = 206) across 11 studies with multiyear follow-up (3.6 vs. 8.5 years, respectively). Duration of EPAG exposure correlated with ferritin reduction (p = 4 × 10-14 ) regardless of response, maximum dose, or degree of initial iron overload. Clearance followed first-order kinetics with faster clearance (half-life 15.3 months) compared with historical responders (47.5 months, p = 8 × 10-10 ). Risk of iron depletion was dependent upon baseline ferritin and duration of therapy. Baseline ferritin did not correlate with response of marrow failure to EPAG or to relapse risk, and timing of iron clearance did not correlate with disease response. In conclusion, EPAG efficiently chelates total body iron comparable to clinically available chelators. Prolonged use can deplete iron and ultimately lead to iron-deficiency anemia mimicking relapse, responsive to iron supplementation.
Assuntos
Anemia Aplástica , Sobrecarga de Ferro , Pancitopenia , Trombocitopenia , Anemia Aplástica/tratamento farmacológico , Benzoatos/efeitos adversos , Ferritinas , Humanos , Hidrazinas , Ferro/uso terapêutico , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/etiologia , Pancitopenia/induzido quimicamente , Pirazóis , Recidiva , Trombocitopenia/induzido quimicamenteRESUMO
Transfusion-dependent patients typically develop iron-induced cardiomyopathy, liver disease, and endocrine complications. We aimed to estimate the incidence of endocrine disorders in transfusiondependent thalassemia (TDT) patients during long-term iron-chelation therapy with deferasirox (DFX). We developed a multi-center follow-up study of 426 TDT patients treated with once-daily DFX for a median duration of 8 years, up to 18.5 years. At baseline, 118, 121, and 187 patients had 0, 1, or ≥2 endocrine diseases respectively. 104 additional endocrine diseases were developed during the follow-up. The overall risk of developing a new endocrine complication within 5 years was 9.7% (95% Confidence Interval [CI]: 6.3-13.1). Multiple Cox regression analysis identified three key predictors: age showed a positive log-linear effect (adjusted hazard ratio [HR] for 50% increase 1.2, 95% CI: 1.1-1.3, P=0.005), the serum concentration of thyrotropin showed a positive linear effect (adjusted HR for 1 mIU/L increase 1.3, 95% CI: 1.1-1.4, P<0.001) regardless the kind of disease incident, while the number of previous endocrine diseases showed a negative linear effect: the higher the number of diseases at baseline the lower the chance of developing further diseasess (adjusted HR for unit increase 0.5, 95% CI: 0.4-0.7, P<0.001). Age and thyrotropin had similar effect sizes across the categories of baseline diseases. The administration of levothyroxine as a covariate did not change the estimates. Although in DFX-treated TDT patients the risk of developing an endocrine complication is generally lower than the previously reported risk, there is considerable risk variation and the burden of these complications remains high. We developed a simple risk score chart enabling clinicians to estimate their patients' risk. Future research will look at increasing the amount of variation explained from our model and testing further clinical and laboratory predictors, including the assessment of direct endocrine magnetic resonance imaging.
Assuntos
Sobrecarga de Ferro , Talassemia , Talassemia beta , Benzoatos/efeitos adversos , Terapia por Quelação/efeitos adversos , Deferasirox/efeitos adversos , Seguimentos , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/epidemiologia , Sobrecarga de Ferro/etiologia , Medição de Risco , Fatores de Risco , Talassemia/complicações , Talassemia/epidemiologia , Talassemia/terapia , Triazóis/efeitos adversos , Talassemia beta/complicaçõesRESUMO
BACKGROUND: Thalassemia major is the severe form of ß thalassemia characterized by severe anaemia, hepatosplenomegaly and facioskeletal changes due to increased haemolysis of defective red blood cells. In iron overload states, high levels of iron exceed the iron-carrying capacity of transferrin within the plasma, leading to the formation of nontransferrin-bound iron form. These nontransferrin-bound iron forms can be taken up into cells, including liver, heart, and endocrine cells leading to organ damage. To prevent complications associated with hemosiderosis, iron chelation therapy remains one of the main objectives of clinical management of the patients affected by Thalassemia Major. METHODS: Thirty-seven patients were enrolled using non randomized convenience sampling technique after the written consent from patients. Patients age 2-30 years were enrolled in this study. Serum Ferritin, ALT, Serum Creatinine were checked at the start of the study, 3 months, 6months and then at the end of the study, i.e., at 9 months of the commencement of the study. They were also assessed for other side effects pertaining to oral tolerability of the drug like vomiting, nausea, GI upset, diarrhoea, urinary complaints or any other subjective complaint. RESULTS: Of the 37 patients, 20 were male (54.1%) and 17 were female (45.9%). Mean age of the patients was 10.2 years (Min. 3 years, Max 21 years). The average serum Ferritin at baseline was noted as 3440 which increased after a period of 3 months, 6 months and 9 months with average of 3359, 3677 and 4394 respectively. After the period of 9 months largest 95% confidence interval of serum Ferritin levels was observed in the range of 3420.17 to 5368.63. In our study, 17 patients required alternative chelation (46%). These patients needed IV Deferioxamine because of the rising trend of Serum Ferritin after the study. CONCLUSIONS: From the results of our study, we infer that oral Deferasirox is not an effective iron chelator. If the patients are taking oral deferasirox, their Serum Ferritin should be checked 3 monthlies. The drug is effective only in maintaining Serum Ferritin levels with levels less than 1500ng/ml. Intravenous Deferioxamine still should be preferred over oral iron chelators for effective control of iron overload and its complications.
Assuntos
Deferasirox/uso terapêutico , Quelantes de Ferro/uso terapêutico , Talassemia beta/tratamento farmacológico , Administração Intravenosa , Adolescente , Adulto , Benzoatos/efeitos adversos , Criança , Pré-Escolar , Deferasirox/administração & dosagem , Deferasirox/efeitos adversos , Contagem de Eritrócitos , Feminino , Hepatomegalia , Humanos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/efeitos adversos , Masculino , Triazóis/efeitos adversos , Adulto JovemRESUMO
OBJECTIVES: To assess the efficacy and safety of dual oral iron chelation therapy (deferiprone and deferasirox) in decreasing iron overload status, using serum ferritin and liver and cardiac MRI as indicators, in transfusion dependent thalassemic children. METHODS: This was a prospective observational study conducted in a tertiary care hospital for a period of one year. Children with thalassemia between 2 and 18 y of age with serum ferritin above 1500 ng/ml were started on oral deferiprone and deferasirox. They were followed up for one year. Serum ferritin and MRI quantification of liver and cardiac iron concentration was done at enrolment and end of 12 mo. They were also monitored monthly for any adverse effects. RESULTS: Twenty one thalassemic children with mean age of 7.8 y (range 4-12 y) and a mean ferritin value of 3129 + 1231.5 ng/ml were enrolled. Mean serum ferritin decreased by 1226.3 ng/ml (p = 0.047, 95% CI =10.2, 1504.3) with 16.8% fall from baseline. The reduction in ferritin correlated significantly with the initial ferritin level (spearman's rho = 0.742, p = 0.001). Mean liver iron concentration and myocardial iron concentration did not change significantly. Red color urine, transient rise in creatinine and liver enzymes were noted during the study period. CONCLUSIONS: Combined oral chelation with deferiprone and deferasirox significantly decreases the serum ferritin level in children with severe iron overload. The drugs were tolerated well without any serious adverse effects.
Assuntos
Sobrecarga de Ferro , Talassemia , Talassemia beta , Benzoatos/efeitos adversos , Criança , Deferasirox , Deferiprona , Humanos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Piridonas/efeitos adversos , Talassemia/complicações , Talassemia/tratamento farmacológicoAssuntos
Benzoatos/efeitos adversos , Hidrazinas/efeitos adversos , Isquemia/etiologia , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirazóis/efeitos adversos , Trombose/induzido quimicamente , Idoso , Biópsia , Clopidogrel/uso terapêutico , Angiografia por Tomografia Computadorizada , Tratamento Conservador , Feminino , Humanos , Oxigenoterapia Hiperbárica , Isquemia/patologia , Isquemia/terapia , Contagem de Plaquetas , Púrpura Trombocitopênica Idiopática/sangue , Pele/irrigação sanguínea , Pele/diagnóstico por imagem , Pele/patologia , Trombose/complicações , Trombose/diagnóstico , Trombose/tratamento farmacológico , Artérias da Tíbia/diagnóstico por imagem , Artérias da Tíbia/patologia , Dedos do Pé/irrigação sanguínea , Dedos do Pé/diagnóstico por imagem , Dedos do Pé/patologia , Resultado do Tratamento , Varfarina/uso terapêuticoRESUMO
BACKGROUND: To compare the efficacy and safety of desferrioxamine (DFO), deferiprone (DFP), deferasirox (DFX) and silymarin in patients with either thalassemia or sickle cell disorder through network meta-analysis. METHODS: Electronic databases were searched for appropriate randomized clinical trials comparing iron chelators in patients with iron overload. Random effects model was used to generate direct, indirect and mixed treatment comparison pooled estimates for the following outcomes: serum ferritin, liver iron concentration (LIC), changes in serum ferritin, mortality, urine iron excretion, adverse events, neutropenia, agranulocytosis and number of patients withdrawing the chelating therapy. RESULTS: Thirty-two clinical trials were included in the meta-analysis. DFX/DFO was associated with better serum ferritin levels compared to DFO, DFX, DFO/Silymarin and DFP/DFO. DFX/DFO also lower LIC significantly compared to DFO. DFP/DFO was associated with higher LVEF, low risk of adverse events and reduced end of serum ferritin compared to DFO. Combination of silymarin with either DFP or DFX was observed with reduced end of treatment serum ferritin compared to using either of the drugs alone. DFP was observed with better effects in sickle cell disease. The strength of evidence was very low for most of the comparisons. CONCLUSION: Relative estimates between the individual iron chelators have been established. However, this evidence should be considered preliminary and may change with the results of future head-to-head clinical trials.
Assuntos
Anemia Falciforme/tratamento farmacológico , Quelantes de Ferro/uso terapêutico , Talassemia/tratamento farmacológico , Benzoatos/administração & dosagem , Benzoatos/efeitos adversos , Benzoatos/uso terapêutico , Deferasirox , Deferiprona , Desferroxamina/administração & dosagem , Desferroxamina/efeitos adversos , Desferroxamina/uso terapêutico , Quimioterapia Combinada , Humanos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro , Metanálise em Rede , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Piridonas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Silimarina/administração & dosagem , Silimarina/efeitos adversos , Silimarina/uso terapêutico , Triazóis/administração & dosagem , Triazóis/efeitos adversos , Triazóis/uso terapêuticoRESUMO
BACKGROUND: Thalassaemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusions. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone are effective; however, a review of the effectiveness and safety of the newer oral chelator deferasirox in people with thalassaemia is needed. OBJECTIVES: To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and iron overload. SEARCH METHODS: We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register: 12 August 2016.We also searched MEDLINE, Embase, the Cochrane Library, Biosis Previews, Web of Science Core Collection and three trial registries: ClinicalTrials.gov; the WHO International Clinical Trials Registry Platform; and the Internet Portal of the German Clinical Trials Register: 06 and 07 August 2015. SELECTION CRITERIA: Randomised controlled studies comparing deferasirox with no therapy or placebo or with another iron-chelating treatment. DATA COLLECTION AND ANALYSIS: Two authors independently assessed risk of bias and extracted data. We contacted study authors for additional information. MAIN RESULTS: Sixteen studies involving 1807 randomised participants (range 23 to 586 participants) were included. Twelve two-arm studies compared deferasirox to placebo (two studies) or deferoxamine (seven studies) or deferiprone (one study) or the combination of deferasirox and deferoxamine to deferoxamine alone (one study). One study compared the combination of deferasirox and deferiprone to deferiprone in combination with deferoxamine. Three three-arm studies compared deferasirox to deferoxamine and deferiprone (two studies) or the combination of deferasirox and deferiprone to deferiprone and deferasirox monotherapy respectively (one study). One four-arm study compared two different doses of deferasirox to matching placebo groups.The two studies (a pharmacokinetic and a dose-escalation study) comparing deferasirox to placebo (n = 47) in people with transfusion-dependent thalassaemia showed that deferasirox leads to net iron excretion. In these studies, safety was acceptable and further investigation in phase II and phase III studies was warranted.Nine studies (1251 participants) provided data for deferasirox versus standard treatment with deferoxamine. Data suggest that a similar efficacy can be achieved depending on the ratio of doses of deferoxamine and deferasirox being compared. In the phase III study, similar or superior efficacy for the intermediate markers ferritin and liver iron concentration (LIC) could only be achieved in the highly iron-overloaded subgroup at a mean ratio of 1 mg of deferasirox to 1.8 mg of deferoxamine corresponding to a mean dose of 28.2 mg per day and 51.6 mg per day respectively. The pooled effects across the different dosing ratios are: serum ferritin, mean difference (MD) 454.42 ng/mL (95% confidence interval (CI) 337.13 to 571.71) (moderate quality evidence); LIC evaluated by biopsy or SQUID, MD 2.37 mg Fe/g dry weight (95% CI 1.68 to 3.07) (moderate quality evidence) and responder analysis, LIC 1 to < 7 mg Fe/g dry weight, risk ratio (RR) 0.80 (95% CI 0.69 to 0.92) (moderate quality evidence). The substantial heterogeneity observed could be explained by the different dosing ratios. Data on mortality (low quality evidence) and on safety at the presumably required doses for effective chelation therapy are limited. Patient satisfaction was better with deferasirox among those who had previously received deferoxamine treatment, RR 2.20 (95% CI 1.89 to 2.57) (moderate quality evidence). The rate of discontinuations was similar for both drugs (low quality evidence).For the remaining comparisons in people with transfusion-dependent thalassaemia, the quality of the evidence for outcomes assessed was low to very low, mainly due to the very small number of participants included. Four studies (205 participants) compared deferasirox to deferiprone; one of which (41 participants) revealed a higher number of participants experiencing arthralgia in the deferiprone group, but due to the large number of different types of adverse events reported and compared this result is uncertain. One study (96 participants) compared deferasirox combined with deferiprone to deferiprone with deferoxamine. Participants treated with the combination of the oral iron chelators had a higher adherence compared to those treated with deferiprone and deferoxamine, but no participants discontinued the study. In the comparisons of deferasirox versus combined deferasirox and deferiprone and that of deferiprone versus combined deferasirox and deferiprone (one study, 40 participants), and deferasirox and deferoxamine versus deferoxamine alone (one study, 94 participants), only a few patient-relevant outcomes were reported and no significant differences were observed.One study (166 participants) included people with non-transfusion dependent thalassaemia and compared two different doses of deferasirox to placebo. Deferasirox treatment reduced serum ferritin, MD -306.74 ng/mL (95% CI -398.23 to -215.24) (moderate quality evidence) and LIC, MD -3.27 mg Fe/g dry weight (95% CI -4.44 to -2.09) (moderate quality evidence), while the number of participants experiencing adverse events and rate of discontinuations (low quality evidence) was similar in both groups. No participant died, but data on mortality were limited due to a follow-up period of only one year (moderate quality evidence). AUTHORS' CONCLUSIONS: Deferasirox offers an important treatment option for people with thalassaemia and secondary iron overload. Based on the available data, deferasirox does not seem to be superior to deferoxamine at the usually recommended ratio of 1 mg of deferasirox to 2 mg of deferoxamine. However, similar efficacy seems to be achievable depending on the dose and ratio of deferasirox compared to deferoxamine. Whether this will result in similar efficacy and will translate to similar benefits in the long term, as has been shown for deferoxamine, needs to be confirmed. Data from randomised controlled trials on rare toxicities and long-term safety are still limited. However, after a detailed discussion of the potential benefits and risks, deferasirox could be offered as the first-line option to individuals who show a strong preference for deferasirox, and may be a reasonable treatment option for people showing an intolerance or poor adherence to deferoxamine.
Assuntos
Benzoatos/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Talassemia/complicações , Triazóis/uso terapêutico , Administração Oral , Benzoatos/administração & dosagem , Benzoatos/efeitos adversos , Ensaios Clínicos Fase II como Assunto , Ensaios Clínicos Fase III como Assunto , Deferasirox , Deferiprona , Desferroxamina/administração & dosagem , Desferroxamina/uso terapêutico , Transfusão de Eritrócitos/efeitos adversos , Ferritinas/sangue , Humanos , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/etiologia , Satisfação do Paciente , Piridonas/administração & dosagem , Piridonas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Talassemia/mortalidade , Talassemia/terapia , Triazóis/administração & dosagem , Triazóis/efeitos adversosRESUMO
Background Food and chemical sensitivities have detrimental effects on health and the quality of life. The natural course of such sensitivities can potentially be altered through various types of allergen-specific immunotherapy, including low-dose immunotherapy. The molecular mechanism by which low-dose immunotherapy causes desensitization has not thus far been elucidated. While resting lymphocytes maintain a low cytosolic calcium ion concentration, antigen receptor signaling results in calcium ion influx, predominantly via store-operated calcium channels. We therefore hypothesized that desensitization by low-dose immunotherapy is associated with reduced influx of calcium ions into lymphocytes. The aim of this study was to test this hypothesis. Methods Intracellular lymphocytic calcium ion concentrations were assayed in a total of 47 patients, following incubation with picogram amounts of the test allergens, using a cell-permeable calcium-sensing ratiometric fluorescent dye and fluorescence spectroscopy, both at baseline and following successful provocation neutralization treatment with low-dose immunotherapy. Results Low-dose immunotherapy was associated with a reduction in lymphocytic intracellular calcium ion concentration following treatment of: 23â% for metabisulfite sensitivity (p<0.0004); 12â% for salicylate sensitivity (p<0.01); 23â% for benzoate sensitivity (p<0.01); 30â% for formaldehyde sensitivity (p<0.0001); 16â% for sensitivity to petrol exhaust (p<0.003); 16â% for natural gas sensitivity (p<0.001); 13â% for nickel sensitivity (p<0.05); 30â% for sensitivity to organophosphates (p<0.01); and 24â% for sensitivity to nitrosamines (p<0.05). Conclusions Low-dose immunotherapy may affect baseline levels of intracellular calcium in lymphocytes, supporting the premise that allergens affect cell signaling in immune cells and provocation neutralization immunotherapy helps to promote more normal immune cell signaling.
Assuntos
Alérgenos , Cálcio/metabolismo , Dessensibilização Imunológica , Doença Ambiental/terapia , Linfócitos/metabolismo , Adulto , Benzoatos/efeitos adversos , Doença Ambiental/metabolismo , Feminino , Hipersensibilidade Alimentar/metabolismo , Hipersensibilidade Alimentar/terapia , Formaldeído/efeitos adversos , Humanos , Masculino , Sensibilidade Química Múltipla/metabolismo , Sensibilidade Química Múltipla/terapia , Gás Natural/efeitos adversos , Níquel/efeitos adversos , Nitrosaminas/efeitos adversos , Organofosfatos/efeitos adversos , Salicilatos/efeitos adversos , Emissões de VeículosRESUMO
Sunscreens are intended to work on the skin. To be both efficient and safe, the lowest possible percutaneous permeation of UV filters should occur. The potential for systemic absorption of Benzophenone-3 (BP3, 10%) and Ethylhexyl Triazone (EHT, 5%) in a silicone-based water-in-oil emulsion was assessed in vitro using a full-thickness porcine-ear skin mimicking in-use conditions. The estimated Systemic Exposure Dose (SED) after the sunscreen application at 1.0 mg/cm2 for 6 h (i) on the face; (ii) on the whole-body skin, was (i) 136 and 30; (ii) 4200 and 933 µg/kg_bw/d for BP3 and EHT, respectively. Reapplication does not mean the double risk; the SED values were only 1.40-1.37-fold greater. Skin shaving increased BP3 and EHT bioavailability 1.38 and 1.80-fold, respectively. Margin of Safety values were estimated according to guidelines applicable for European Union. For three realistic exposure scenarios, MoS of 48, 34 and 34 for BP3 in the sunscreen applied on the whole-body indicate some concerns regarding the safety for consumers (MoS<100). Despite undeniable functional benefits in sunscreens, BP3 concentration allowed in EU cosmetics (max. 10%) should be reviewed, especially in products intended for whole-body applications. The development of new UV filters should be focused on their specific physico-chemical properties.
Assuntos
Benzofenonas/efeitos adversos , Avaliação Pré-Clínica de Medicamentos/métodos , Absorção Cutânea/efeitos dos fármacos , Pele/efeitos dos fármacos , Protetores Solares/efeitos adversos , Animais , Benzoatos/efeitos adversos , Comportamento do Consumidor , Emulsões , Congelamento , Hábitos , Humanos , Protetores Solares/administração & dosagem , Protetores Solares/química , Suínos , Triazinas/efeitos adversos , Raios UltravioletaRESUMO
BACKGROUND: Iron chelation therapy is one of the mainstays of the management of the patients with ß-thalassemia (BT) major. Deferasirox is an oral active iron chelating agent. Proteinuria is one of the potential renal adverse effects of deferasirox, and monthly follow-up for proteinuria is suggested by Food and Drug Administration and European Medicine Agency. METHODS: We aimed to investigate the necessity for monthly monitoring for proteinuria among patients with BT on deferasirox. A retrospective laboratory and clinic data review was performed for patients with BT major or intermedia who were treated with deferasirox chelation therapy. All patients were monitored for proteinuria for every 3 or 4 weeks after the initiation of deferasirox with serum creatinine and spot urine protein/creatinine ratios. RESULTS: The median follow-up time of the 37 (36 BT major and one BT intermedia) patients was 44 months. Seven patients (18.9%) developed significant proteinuria (ratio ≥0.8). Of the 1490 measurements, 12 tests (0.8%) were proteinuric. Urine proteinuria resolved in all of the patients during the follow-up. The risk of proteinuria was higher at ages below a cut-off point of 23 years (p = 0.019). Patients, who were on deferasirox at doses above a cut-off dose of 29â mg/kg/day, were found to have higher risk of proteinuria development (p = 0.004). CONCLUSION: Proteinuria resolves without any complication or major intervention according to our results. Potentially more risky groups (age below 23 years old and receivers above a dose of 29â mg/kg/day) might be suggested to be followed monthly, besides monitoring all of the patients.
Assuntos
Benzoatos/efeitos adversos , Proteinúria/urina , Triazóis/efeitos adversos , Talassemia beta/tratamento farmacológico , Talassemia beta/urina , Adolescente , Adulto , Benzoatos/uso terapêutico , Criança , Pré-Escolar , Deferasirox , Feminino , Humanos , Masculino , Proteinúria/induzido quimicamente , Proteinúria/diagnóstico , Estudos Retrospectivos , Triazóis/uso terapêutico , Adulto Jovem , Talassemia beta/sangueRESUMO
Deferasirox is a standard treatment for chronic transfusional iron overload. Adverse effects of deferasirox have been reported in large prospective studies. We report two cases of monozygotic twins manifesting with proximal muscular atrophy and weakness under deferasirox. Discontinuation of deferasirox resulted in symptom improvement and ultimately in complete remission five months after successful haematopoietic stem cell transplantation. Broad diagnostic work-up could not bring evidence of another aetiology of muscular weakness. Iron overload or beta thalassemia itself as a cause is considered unlikely in our patients because the chronological coincidence of muscular symptoms was contra-directional to serum ferritin levels and significant clinical improvement was observed promptly after cessation of deferasirox even before transplantation. These observations suggest that the development of muscular weakness in patients on deferasirox should be recognised as a possible adverse effect of the drug.
Assuntos
Benzoatos/efeitos adversos , Terapia por Quelação/efeitos adversos , Quelantes de Ferro/efeitos adversos , Debilidade Muscular/induzido quimicamente , Atrofia Muscular/induzido quimicamente , Triazóis/efeitos adversos , Benzoatos/uso terapêutico , Criança , Pré-Escolar , Deferasirox , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Ferro , Quelantes de Ferro/uso terapêutico , Debilidade Muscular/diagnóstico por imagem , Debilidade Muscular/fisiopatologia , Debilidade Muscular/terapia , Atrofia Muscular/diagnóstico por imagem , Atrofia Muscular/fisiopatologia , Atrofia Muscular/terapia , Transplante Homólogo , Triazóis/uso terapêutico , Gêmeos Monozigóticos , Talassemia beta/complicações , Talassemia beta/diagnóstico por imagem , Talassemia beta/tratamento farmacológico , Talassemia beta/fisiopatologiaRESUMO
OBJECTIVE: To compare the efficacy and safety of oral iron chelators (Deferiprone and Deferasirox) when used singly and in combination in multi-transfused children with thalassemia. DESIGN: Prospective comparative study. SETTING: Thalassemia Center of a medical college affiliated hospital. PARTICIPANTS AND INTERVENTION: 49 multi-transfused children with thalassemia with a mean (SD) age 11.6 (6.21) y received daily chelation therapy with either deferiprone alone (75 mg/kg/day in 3 divided doses), deferasirox alone (30 mg/kg/day single dose) or their daily combination (same dose as monotherapy) for 12 months. OUTCOME MEASURES: Serum ferritin levels at the start of study, after 6 months and after 12 months. MRI T2* of liver and heart initially and after 6 months of follow up. 24-hour urinary iron excretion values at the outset and after 12 months of chelation therapy. At every visit for blood transfusion, all patients were clinically assessed for any adverse effects; liver and renal functions were monitored 6-monthly. RESULTS: After 12 months of respective chelation therapy, serum ferritin values decreased from a mean of 3140.5 ng/mL to 2910.0 ng/mL in deferiprone alone group, 3859.2 ng/mL to 3417.4 ng/mL in deferasirox alone group and from 3696.5 ng/mL to 2572.1 ng/mL in the combination group. The combination therapy was more efficacious in causing fall in serum ferritin levels compared to deferiprone and deferasirox monotherapy (P= 0.035 and 0.040, respectively). Results of MRI T2 were equivocal. Combined drug usage produced maximum negative iron balance in the body by maximally increasing the iron excretion in urine from 61.1 umol/day to 343.3 umol/day (P = 0.002). No significant adverse reactions were noticed in either the monotherapy or the combination group. CONCLUSION: Oral combination therapy of deferiprone and deferasirox appears to be an efficacious and safe modality to reduce serum ferritin in multi-transfused children with thalassemia.