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1.
Int J Mol Sci ; 24(23)2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-38069073

RESUMO

The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.


Assuntos
Sobrecarga de Ferro , Talassemia beta , Humanos , Deferiprona/uso terapêutico , Desferroxamina/uso terapêutico , Piridonas/efeitos adversos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/induzido quimicamente , Terapia por Quelação/métodos , Ferro/metabolismo , Talassemia beta/tratamento farmacológico , Talassemia beta/complicações , Quimioterapia Combinada
2.
Cochrane Database Syst Rev ; 11: CD011626, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37975597

RESUMO

BACKGROUND: Beta-thalassaemia is an inherited blood disorder that reduces the production of haemoglobin. The most severe form requires recurrent blood transfusions, which can lead to iron overload. Cardiovascular dysfunction caused by iron overload is the leading cause of morbidity and mortality in people with transfusion-dependent beta-thalassaemia. Iron chelation therapy has reduced the severity of systemic iron overload, but removal of iron from the myocardium requires a very proactive preventive strategy. There is evidence that calcium channel blockers may reduce myocardial iron deposition. This is an update of a Cochrane Review first published in 2018. OBJECTIVES: To assess the effects of calcium channel blockers plus standard iron chelation therapy, compared with standard iron chelation therapy (alone or with a placebo), on cardiomyopathy due to iron overload in people with transfusion-dependent beta thalassaemia. SEARCH METHODS: We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books, to 13 January 2022. We also searched ongoing trials databases and the reference lists of relevant articles and reviews. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of calcium channel blockers combined with standard chelation therapy versus standard chelation therapy alone or combined with placebo in people with transfusion-dependent beta thalassaemia. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used GRADE to assess certainty of evidence. MAIN RESULTS: We included six RCTs (five parallel-group trials and one cross-over trial) with 253 participants; there were 126 participants in the amlodipine arms and 127 in the control arms. The certainty of the evidence was low for most outcomes at 12 months; the evidence for liver iron concentration was of moderate certainty, and the evidence for adverse events was of very low certainty. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may have little or no effect on cardiac T2* values at 12 months (mean difference (MD) 1.30 ms, 95% confidence interval (CI) -0.53 to 3.14; 4 trials, 191 participants; low-certainty evidence) and left ventricular ejection fraction (LVEF) at 12 months (MD 0.81%, 95% CI -0.92% to 2.54%; 3 trials, 136 participants; low-certainty evidence). Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may reduce myocardial iron concentration (MIC) after 12 months (MD -0.27 mg/g, 95% CI -0.46 to -0.08; 3 trials, 138 participants; low-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on heart T2*, MIC, or LVEF after six months, but the evidence is very uncertain. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may increase liver T2* values after 12 months (MD 1.48 ms, 95% CI 0.27 to 2.69; 3 trials, 127 participants; low-certainty evidence), but may have little or no effect on serum ferritin at 12 months (MD 0.07 µg/mL, 95% CI -0.20 to 0.35; 4 trials, 187 participants; low-certainty evidence), and probably has little or no effect on liver iron concentration (LIC) after 12 months (MD -0.86 mg/g, 95% CI -4.39 to 2.66; 2 trials, 123 participants; moderate-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on serum ferritin, liver T2* values, or LIC after six months, but the evidence is very uncertain. The included trials did not report any serious adverse events at six or 12 months of intervention. The studies did report mild adverse effects such as oedema, dizziness, mild cutaneous allergy, joint swelling, and mild gastrointestinal symptoms. Amlodipine may be associated with a higher risk of oedema (risk ratio (RR) 5.54, 95% CI 1.24 to 24.76; 4 trials, 167 participants; very low-certainty evidence). We found no difference between the groups in the occurrence of other adverse events, but the evidence was very uncertain. No trials reported mortality, cardiac function assessments other than echocardiographic estimation of LVEF, electrocardiographic abnormalities, quality of life, compliance with treatment, or cost of interventions. AUTHORS' CONCLUSIONS: The available evidence suggests that calcium channel blockers may reduce MIC and may increase liver T2* values in people with transfusion-dependent beta thalassaemia. Longer-term multicentre RCTs are needed to assess the efficacy and safety of calcium channel blockers for myocardial iron overload, especially in younger children. Future trials should also investigate the role of baseline MIC in the response to calcium channel blockers, and include a cost-effectiveness analysis.


Assuntos
Cardiomiopatias , Sobrecarga de Ferro , Talassemia beta , Criança , Humanos , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/prevenção & controle , Sobrecarga de Ferro/complicações , Ferro/uso terapêutico , Cardiomiopatias/etiologia , Cardiomiopatias/prevenção & controle , Anlodipino/efeitos adversos , Quelantes de Ferro/efeitos adversos , Ferritinas , Edema
3.
Indian J Pharmacol ; 55(5): 335-337, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37929413

RESUMO

Iron chelators have significantly reduced the morbidity associated with iron overload and improved the quality of life in children with beta-thalassemia major. A 5-year-old female child with beta-thalassemia major on recurrent transfusions and oral chelation with deferasirox was brought with repeated episodes of frank hematemesis and progressive lethargy. Her evaluation revealed anemia, leukocytosis, and deranged liver function with coagulopathy. She was given red blood cell and plasma transfusions with liver supportive medication and proton-pump inhibitor (PPI) infusion. Her upper gastrointestinal endoscopy revealed multiple ulcers in all three parts of the duodenum, which in the absence of any other likely etiology were attributed to prolonged use of oral deferasirox. The child improved with the above-mentioned measures. Chelation therapy was withheld for 2 weeks and restarted at a lower dose using enteric-coated preparation while PPIs were given for 8 weeks. She showed sustained improvement and remained well on follow-up.


Assuntos
Úlcera Duodenal , Choque Hemorrágico , Talassemia beta , Pré-Escolar , Feminino , Humanos , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Deferasirox/efeitos adversos , Úlcera Duodenal/induzido quimicamente , Úlcera Duodenal/tratamento farmacológico , Quelantes de Ferro/efeitos adversos , Qualidade de Vida , Choque Hemorrágico/tratamento farmacológico
4.
Ann N Y Acad Sci ; 1529(1): 33-41, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37594980

RESUMO

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 Combinada
5.
Am J Hematol ; 98(9): 1415-1424, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37401738

RESUMO

Children with transfusion-dependent thalassemia (TDT) require regular blood transfusions that, without iron-chelation therapy, lead to iron-overload toxicities. Current practice delays chelation therapy (late-start) until reaching iron overload (serum ferritin ≥1000 µg/L) to minimize risks of iron-depletion. Deferiprone's distinct pharmacological properties, including iron-shuttling to transferrin, may reduce risks of iron depletion during mild-to-moderate iron loads and iron overload/toxicity in children with TDT. The early-start deferiprone (START) study evaluated the efficacy/safety of early-start deferiprone in infants/young children with TDT. Sixty-four infants/children recently diagnosed with beta-thalassemia and serum ferritin (SF) between 200 and 600 µg/L were randomly assigned 1:1 to receive deferiprone or placebo for 12 months or until reaching SF-threshold (≥1000 µg/L at two consecutive visits). Deferiprone was initiated at 25 mg/kg/day and increased to 50 mg/kg/day; some recipients' dosages increased to 75 mg/kg/day based on iron levels. The primary endpoint was the proportion of patients ≥SF-threshold by month 12. Monthly transferrin saturation (TSAT) assessment evaluated iron-shuttling. At baseline, there was no significant difference in mean age (deferiprone: 3.03 years, placebo: 2.63 years), SF (deferiprone: 513.8 µg/L, placebo: 451.7 µg/L), or TSAT (deferiprone: 47.98%, placebo: 43.43%) between groups. At month 12, there was no significant difference in growth or adverse event (AE) rates between groups. No deferiprone-treated patients were iron-depleted. At month 12, 66% of patients receiving deferiprone remained below SF threshold versus 39% of placebo (p = .045). Deferiprone-treated patients showed higher TSAT levels and reached ≥60% TSAT threshold faster. Early-start deferiprone was well-tolerated, not associated with iron depletion, and efficacious in reducing iron overload in infants/children with TDT. TSAT results provide the first clinical evidence of deferiprone shuttling iron to transferrin.


Assuntos
Sobrecarga de Ferro , Talassemia beta , Humanos , Criança , Lactente , Pré-Escolar , Ferro , Talassemia beta/tratamento farmacológico , Quelantes de Ferro/efeitos adversos , Transferrina , Ferritinas , Piridonas/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia
6.
Ann Hematol ; 102(8): 2039-2049, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37227493

RESUMO

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 adversos
7.
Transfus Apher Sci ; 62(3): 103702, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37055329

RESUMO

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/terapia
8.
EMBO Mol Med ; 15(2): e16525, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36645044

RESUMO

Iron accumulation causes cell death and disrupts tissue functions, which necessitates chelation therapy to reduce iron overload. However, clinical utilization of deferoxamine (DFO), an iron chelator, has been documented to give rise to systemic adverse effects, including ocular toxicity. This study provided the pathogenic and molecular basis for DFO-related retinopathy and identified retinal pigment epithelium (RPE) as the target tissue in DFO-related retinopathy. Our modeling demonstrated the susceptibility of RPE to DFO compared with the neuroretina. Intriguingly, we established upregulation of hypoxia inducible factor (HIF) 2α and mitochondrial deficit as the most prominent pathogenesis underlying the RPE atrophy. Moreover, suppressing hyperactivity of HIF2α and preserving mitochondrial dysfunction by α-ketoglutarate (AKG) protects the RPE against lesions both in vitro and in vivo. This supported our observation that AKG supplementation alleviates visual impairment in a patient undergoing DFO-chelation therapy. Overall, our study established a significant role of iron deficiency in initiating DFO-related RPE atrophy. Inhibiting HIF2α and rescuing mitochondrial function by AKG protect RPE cells and can potentially ameliorate patients' visual function.


Assuntos
Quelantes de Ferro , Doenças Retinianas , Humanos , Quelantes de Ferro/efeitos adversos , Morte Celular , Atrofia/induzido quimicamente
9.
J Pharm Pract ; 36(4): 749-755, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35473439

RESUMO

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 , Ferritinas
10.
Int J Mol Sci ; 23(12)2022 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-35743183

RESUMO

The need for preparing new strategies for the design of emergency drug therapies against COVID-19 and similar diseases in the future is rather urgent, considering the high rate of morbidity and especially mortality associated with COVID-19, which so far has exceeded 18 million lives. Such strategies could be conceived by targeting the causes and also the serious toxic side effects of the diseases, as well as associated biochemical and physiological pathways. Deferiprone (L1) is an EMA- and FDA-approved drug used worldwide for the treatment of iron overload and also other conditions where there are no effective treatments. The multi-potent effects and high safety record of L1 in iron loaded and non-iron loaded categories of patients suggests that L1 could be developed as a "magic bullet" drug against COVID-19 and diseases of similar symptomatology. The mode of action of L1 includes antiviral, antimicrobial, antioxidant, anti-hypoxic and anti-ferroptotic effects, iron buffering interactions with transferrin, iron mobilizing effects from ferritin, macrophages and other cells involved in the immune response and hyperinflammation, as well as many other therapeutic interventions. Similarly, several pharmacological and other characteristics of L1, including extensive tissue distribution and low cost of production, increase the prospect of worldwide availability, as well as many other therapeutic approach strategies involving drug combinations, adjuvant therapies and disease prevention.


Assuntos
Tratamento Farmacológico da COVID-19 , Sobrecarga de Ferro , Adulto , Deferiprona/uso terapêutico , Humanos , Ferro/uso terapêutico , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/etiologia , Piridonas/farmacologia , Piridonas/uso terapêutico
11.
J Clin Pharm Ther ; 47(10): 1619-1626, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35748618

RESUMO

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 adversos
13.
Ann Hematol ; 101(3): 533-539, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34981144

RESUMO

Patients with sickle cell disease (SCD) who undergo repeated blood transfusions often develop iron overload. Deferiprone (Ferriprox®) is an oral iron chelator indicated for the treatment of transfusional iron overload due to thalassemia syndromes and has been recently approved as a treatment for iron overload in adult and pediatric patients with SCD and other anemias. The present study aims to characterize the pharmacokinetic (PK) profile of deferiprone (DFP) in adult subjects with SCD. In this phase I, open-label study, subjects with SCD were administered a single 1500 mg dose of DFP. Blood and urine samples were collected for PK assessments of DFP and its main metabolite, deferiprone 3-O-glucuronide (DFP-G). Eight subjects were enrolled and completed the study. Following drug administration, serum levels of DFP and DFP-G rose to maximum concentrations at 1.0 and 2.8 h post-dose, respectively. The half-lives of DFP and DFP-G were 1.5 and 1.6 h, respectively. The majority of administered drug was metabolized and excreted as DFP-G, with less than 4% excreted unchanged in urine up to 10 h post-dose. Subjects received a safety assessment 7 (± 3) days post-dose. Two subjects reported mild adverse events unrelated to the study drug, and no other safety concerns were reported. The PK profile of DFP in SCD subjects is consistent with previous reports in healthy adult volunteers, suggesting no special dosing adjustments are indicated for this population. These findings provide valuable insight for treating iron overload in patients with SCD, who have limited chelation therapy treatment options (trial registration number: NCT01835496, date of registration: April 19, 2013).


Assuntos
Anemia Falciforme/complicações , Deferiprona/farmacocinética , Quelantes de Ferro/farmacocinética , Sobrecarga de Ferro/tratamento farmacológico , Adulto , Anemia Falciforme/terapia , Transfusão de Sangue , Terapia por Quelação/efeitos adversos , Deferiprona/efeitos adversos , Deferiprona/uso terapêutico , Feminino , Humanos , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/etiologia , Masculino , Adulto Jovem
14.
J Pediatr Hematol Oncol ; 44(1): e26-e34, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34986131

RESUMO

BACKGROUND: Studies on the increased body iron load in patients with thalassemia major have thoroughly demonstrated the problems caused by iron overload. In patients who undergo hematopoietic stem cell transplantation (HSCT) as curative therapy, iron overload continues long after transplantation. There are few pediatric studies on chelation therapy in the posttransplant period. In this study, we present the outcomes of our patients who received posttransplant oral chelation therapy. PATIENTS AND METHODS: This retrospective observational study evaluated the outcomes of pediatric patients with thalassemia major who used oral chelation therapy after allogeneic HSCT at the Akdeniz University Pediatric Bone Marrow Unit between January 2008 and October 2019. RESULTS: Deferasirox therapy was initiated in 58 pediatric patients who underwent HSCT for thalassemia. Pretreatment mean serum ferritin was 2166±1038 ng/mL. Treatment was initiated at a mean of 12±6.7 months after transplantation and continued for a mean of 15.7±11.5 months. At treatment discontinuation, the mean serum ferritin was 693±405 ng/mL and the mean reduction was -1472.75±1121.09 ng/mL (P<0.001 vs. posttreatment). Serum ferritin was below 500 ng/mL in 52% of the patients at treatment discontinuation. Manageable side effects such as nausea, vomiting, liver enzyme elevation, and proteinuria were observed in 17% of the patients, while one patient developed ototoxicity. CONCLUSIONS: Deferasirox therapy effectively reduces iron overload in the posttransplant period. Studies evaluating the effects of early treatment on the graft may help to establish guidelines for posttransplant chelation therapy. Clear guidelines are needed regarding when to initiate and discontinue treatment.


Assuntos
Deferasirox/administração & dosagem , Transplante de Células-Tronco Hematopoéticas , Quelantes de Ferro/administração & dosagem , Sobrecarga de Ferro/terapia , Talassemia/terapia , Adolescente , Aloenxertos , Criança , Pré-Escolar , Deferasirox/efeitos adversos , Feminino , Ferritinas/sangue , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/sangue , Masculino , Estudos Retrospectivos , Talassemia/sangue
15.
Drug Chem Toxicol ; 45(1): 93-102, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31905029

RESUMO

We aimed to investigate the role of urinary kidney injury molecule-1 (KIM-1) in detection of subclinical nephrotoxicity in patients with Beta-thalassemia (ß-TM) in relation to chelation therapy and to correlate the urinary KIM-1 level with other clinical and laboratory findings. We conducted a cross-sectional study on 66 thalassemic patients. Their ages range from 7 to 22 years. Routine kidney indices and novel urinary KIM/creatinine ratio (UKIM-1/Cr) were measured. Estimated glomerular filtration rate (eGFR) was calculated. Results indicate that the level of serum creatinine was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [median(IQR), 0.85(0.63-0.99), 0.50(0.34-0.58) and 0.44(0.36-0.45)] mg/dL, respectively, p < 0.001]. The median(IQR) level of eGFR was significantly lower in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy [63.3(56.5-92.1), 117.3(91.9-162) and 136.7(109.4-157.6)] ml/min/1.73 m2, respectively, p < 0.001]. The mean level of UKIM-1/Cr was significantly higher in patients on deferasirox therapy than patients on deferoxamine and deferiprone therapy (7.0 ± 1.9, 4.1 ± 1.7 and 4.2 ± 1.5) ng/mg creatinine, respectively, p < 0.001). We concluded that urinary KIM-1 is an early predictive biomarker for decline in eGFR in patients with ß-TM on deferasirox therapy. The appropriate chelation therapy and good monitoring of those patients are intensely needed for early detection of renal dysfunction and timely intervention.


Assuntos
Sobrecarga de Ferro , Talassemia beta , Adolescente , Adulto , Criança , Estudos Transversais , Deferasirox , Desferroxamina/efeitos adversos , Humanos , Quelantes de Ferro/efeitos adversos , Rim , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico
16.
Haematologica ; 107(2): 467-477, 2022 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33406815

RESUMO

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/complicações
17.
Blood Adv ; 6(4): 1243-1254, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-34847228

RESUMO

Many people with sickle cell disease (SCD) or other anemias require chronic blood transfusions, which often causes iron overload that requires chelation therapy. The iron chelator deferiprone is frequently used in individuals with thalassemia syndromes, but data in patients with SCD are limited. This open-label study assessed the efficacy and safety of deferiprone in patients with SCD or other anemias receiving chronic transfusion therapy. A total of 228 patients (mean age: 16.9 [range, 3-59] years; 46.9% female) were randomized to receive either oral deferiprone (n = 152) or subcutaneous deferoxamine (n = 76). The primary endpoint was change from baseline at 12 months in liver iron concentration (LIC), assessed by R2* magnetic resonance imaging (MRI). The least squares mean (standard error) change in LIC was -4.04 (0.48) mg/g dry weight for deferiprone vs -4.45 (0.57) mg/g dry weight for deferoxamine, with noninferiority of deferiprone to deferoxamine demonstrated by analysis of covariance (least squares mean difference 0.40 [0.56]; 96.01% confidence interval, -0.76 to 1.57). Noninferiority of deferiprone was also shown for both cardiac T2* MRI and serum ferritin. Rates of overall adverse events (AEs), treatment-related AEs, serious AEs, and AEs leading to withdrawal did not differ significantly between the groups. AEs related to deferiprone treatment included abdominal pain (17.1% of patients), vomiting (14.5%), pyrexia (9.2%), increased alanine transferase (9.2%) and aspartate transferase levels (9.2%), neutropenia (2.6%), and agranulocytosis (0.7%). The efficacy and safety profiles of deferiprone were acceptable and consistent with those seen in patients with transfusion-dependent thalassemia. This trial study was registered at www://clinicaltrials.gov as #NCT02041299.


Assuntos
Anemia Falciforme , Sobrecarga de Ferro , Talassemia , Adolescente , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Transfusão de Sangue , Deferiprona/uso terapêutico , Desferroxamina/efeitos adversos , Feminino , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Masculino , Piridonas/efeitos adversos , Talassemia/complicações , Talassemia/tratamento farmacológico , Transferases
18.
BMC Ophthalmol ; 21(1): 277, 2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34256738

RESUMO

BACKGROUND: Deferoxamine retinopathy is the informally designated term used to describe a characteristic pattern of outer retinal degeneration in iron-overloaded chronic anemia patients who are treated with deferoxamine. We hypothesize that insufficiently treated iron overloading and not only deferoxamine is the cause of the retinal degeneration. Our case report is based on exposure histories of two anemia patients and literature review. CASE PRESENTATION: Both anemia patients presented with bilateral visual loss secondary to photoreceptor and retinal pigment epithelium degeneration. Chart review showed that visual loss came after a year-long slow, and rather monotonous rise in plasma ferritin concentrations, with no obvious relation to iron chelator exposure. In one patient, the onset of symptomatic visual loss came after a bout of fever followed by two additional febrile episodes, all accompanied by plasma ferritin spikes. Adjustment of iron chelation therapy did not improve visual function. Experimental studies clearly show that both systemic and intraocular exposure to iron ions can induce retinal degeneration. CONCLUSION: The available evidence indicates that retinal degeneration in chronic anemia patients treated by deferoxamine is cause by insufficient iron chelation, not by deferoxamine. The actual role of iron chelating agents may be to promote a long enough survival to allow the slow development of retinal siderosis.


Assuntos
Sobrecarga de Ferro , Degeneração Retiniana , Talassemia beta , Desferroxamina/efeitos adversos , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/tratamento farmacológico , Degeneração Retiniana/induzido quimicamente , Epitélio Pigmentado da Retina
19.
J Ayub Med Coll Abbottabad ; 33(2): 207-212, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34137530

RESUMO

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 Jovem
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