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Abbas M, Nawaz R, Iqbal T, Alim M, Asi MR. Quantitative determination of deferiprone in human plasma by reverse phase high performance liquid chromatography and its application to pharmacokinetic study. PAKISTAN JOURNAL OF PHARMACEUTICAL SCIENCES 2012; 25:343-348. [PMID: 22459459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Deferiprone (1, 2 dimethyl-3-hydroxypyrid-4-one) is considered to be the standard iron chelator. Pharmacokinetic studies of generic formulations are required in local condition before placed on the market. High performance liquid chromatographic (HPLC) method was used for quantification of deferiprone in human plasma using UV/VIS detector. Chromatographic separation was carried out on C(18) column, with a mobile phase of methanol-buffer (18:82, v/v), pH 3.5, and caffeine was used as an internal standard. The calibration curve was linear over the range 0.25-10 μg/mL in human plasma (R(2) = 0.9994). After oral administration of deferiprone (500 mg) to human, the plasma concentration-time curve of deferiprone was conformed to two-compartment open model. The deferiprone plasma concentration showed a rapid absorption and average area under the plasma concentration-time curve (AUC) of deferiprone was 17.0 ± 1.23 h.μg/ml. Average absorption and elimination half-life values of deferiprone of 24 volunteers were 0.62 ± 0.12 and 2.65 ± 0.43 hours. This study confirms the rapid absorption of deferiprone in humans. AUC was similar to that previously reported but C(max) was slightly lower than that stated in the literature.
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Deferiprone (Ferriprox) for iron overload. THE MEDICAL LETTER ON DRUGS AND THERAPEUTICS 2012; 54:15-16. [PMID: 22354281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Alpendurada F, Smith GC, Carpenter JP, Nair SV, Tanner MA, Banya W, Dessi C, Galanello R, Walker JM, Pennell DJ. Effects of combined deferiprone with deferoxamine on right ventricular function in thalassaemia major. J Cardiovasc Magn Reson 2012; 14:8. [PMID: 22277065 PMCID: PMC3278357 DOI: 10.1186/1532-429x-14-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 01/25/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Combination therapy with deferoxamine and oral deferiprone is superior to deferoxamine alone in removing cardiac iron and improving left ventricular ejection fraction (LVEF). The right ventricle (RV) is also affected by the toxic effects of iron and may cause additional cardiovascular perturbation. We assessed the effects of combination therapy on the RV in thalassaemia major (TM) using cardiovascular magnetic resonance (CMR). METHODS We retrieved imaging data from 2 treatment trials and re-analyzed the data for the RV responses: Trial 1 was a randomized controlled trial (RCT) of 65 TM patients with mild-moderate cardiac siderosis receiving combination therapy or deferoxamine with placebo; Trial 2 was an open label longitudinal trial assessing combination therapy in 15 TM patients with severe iron loading. RESULTS In the RCT, combination therapy with deferoxamine and deferiprone was superior to deferoxamine alone for improving RVEF (3.6 vs 0.7%, p = 0.02). The increase in RVEF was greater with lower baseline T2* 8-12 ms (4.7 vs 0.5%, p = 0.01) than with T2* 12-20 ms (2.2 vs 0.8%, p = 0.47). In patients with severe cardiac siderosis, substantial improvement in RVEF was seen with open-label combination therapy (10.5% ± 5.6%, p < 0.01). CONCLUSIONS In the RCT of mild to moderate cardiac iron loading, combination treatment improved RV function significantly more than deferoxamine alone. Combination treatment also improved RV function in severe cardiac siderosis. Therefore adding deferiprone to deferoxamine has beneficial effects on both RV and LV function in TM patients with cardiac siderosis.
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Abstract
BACKGROUND AND PURPOSE Superficial siderosis is a neurodegenerative disease caused by toxic accumulation of hemosiderin on the surface of the brain and spinal cord for which there is no known effective treatment. METHODS Oral deferiprone, a lipid-soluble iron chelator with ability to cross the blood-brain barrier, at a dose of 30 mg/kg per day was tested for safety in an open pilot study in 10 subjects with superficial siderosis. RESULTS Over a 90-day period, deferiprone had no significant adverse effects on hematologic, liver, or neurological function. Ad hoc MRI assessments of the brain indicated a reduction in hemosiderin deposition in some subjects. CONCLUSIONS Deferiprone proved safe in this small population of superficial siderosis subjects. There was MRI evidence of reduced hemosiderin deposition with deferiprone. Prospectively designed efficacy studies are necessary to determine the clinical efficacy of deferiprone in superficial siderosis.
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Musallam KM, Taher AT. Deferiprone or deferasirox for cardiac siderosis in beta-thalassemia major. Haematologica 2011; 96:e5-6; author reply e7-8. [PMID: 21282714 DOI: 10.3324/haematol.2010.036061] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Smith GC, Alpendurada F, Carpenter JP, Alam MH, Berdoukas V, Karagiorga M, Ladis V, Piga A, Aessopos A, Gotsis ED, Tanner MA, Westwood MA, Galanello R, Roughton M, Pennell DJ. Effect of deferiprone or deferoxamine on right ventricular function in thalassemia major patients with myocardial iron overload. J Cardiovasc Magn Reson 2011; 13:34. [PMID: 21733147 PMCID: PMC3148987 DOI: 10.1186/1532-429x-13-34] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 07/06/2011] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Thalassaemia major (TM) patients need regular blood transfusions that lead to accumulation of iron and death from heart failure. Deferiprone has been reported to be superior to deferoxamine for the removal of cardiac iron and improvement in left ventricular (LV) function but little is known of their relative effects on the right ventricle (RV), which is being increasingly recognised as an important prognostic factor in cardiomyopathy. Therefore data from a prospective randomised controlled trial (RCT) comparing these chelators was retrospectively analysed to assess the RV responses to these drugs. METHODS In the RCT, 61 TM patients were randomised to receive either deferiprone or deferoxamine monotherapy, and CMR scans for T2* and cardiac function were obtained. Data were re-analysed for RV volumes and function at baseline, and after 6 and 12 months of treatment. RESULTS From baseline to 12 months, deferiprone reduced RV end systolic volume (ESV) from 37.7 to 34.2 mL (p=0.008), whilst RV ejection fraction (EF) increased from 69.6 to 72.2% (p=0.001). This was associated with a 27% increase in T2* (p<0.001) and 3.1% increase in LVEF (p<0.001). By contrast, deferoxamine showed no change in RVESV (38.1 to 39.1 mL, p=0.38), or RVEF (70.0 to 69.9%, p=0.93) whereas the T2* increased by 13% (p<0.001), but with no change in LVEF (0.32%; p=0.66). Analysis of between drugs treatment effects, showed significant improvements favouring deferiprone with a mean effect on RVESV of -1.82 mL (p=0.014) and 1.16% for RVEF (p=0.009). Using regression analysis the improvement in RVEF at 12 months was shown to be greater in patients with lower baseline EF values (p<0.001), with a significant difference in RVEF of 3.5% favouring deferiprone over deferoxamine (p=0.012). CONCLUSION In this retrospective analysis of a prospective RCT, deferiprone monotherapy was superior to deferoxamine for improvement in RVEF and end-systolic volume. This improvement in the RV volumes and function may contribute to the improved cardiac outcomes seen with deferiprone.
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Torcharus K, Pankaew T. Health-related quality of life in Thai thalassemic children treated with iron chelation. THE SOUTHEAST ASIAN JOURNAL OF TROPICAL MEDICINE AND PUBLIC HEALTH 2011; 42:951-959. [PMID: 22299478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Thalassemia is a chronic hereditary disease in which patients with severe disease present with anemia during their first year of life. In Thailand, stem cell transplantation is not an option for most patients. Supportive treatments, such as blood transfusions and iron chelation are used. Little data exists regarding the Health Related Quality of Life (HRQoL) of these patients. We conducted a study of the four dimensions of quality of life: physical, emotional, social, and role (school) functioning, using the PedsQL 4.0 Generic Core Scale to measure the HRQoL among thalassemic patients at the Hematology Unit, Department of Pediatrics, Phramongkutklao Hospital, during December 1, 2006 - November 30, 2007 to evaluate the quality of life in thalassemic patients treated with three iron-chelating agents. Forty-nine thalassemic patients were enrolled and treated with iron-chelating agents. The mean (SD) age of the patients was 10.61 years (4.33). Fifteen thalassemic patients were treated with desferrioxamine, 18 with deferiprone and 16 with deferasirox. The quality of life (QOL) results show the mean (SD) total summary score was 74.35 (12.42). For the psychosocial health summary, the social and school functioning scores were 85.40 (16.67) and 62.14 (15.84), respectively. The QOL scores of the patients who received desferrioxamine, deferiprone and deferasirox were 75.29 (9.09), 73.91 (15.25) and 73.98 (12.32), respectively (p = 0.94). The QOL had no significant differences by age, gender, type of thalassemia or serum ferritin level. Multivariate regression analysis showed no significant differences in clinical severity, age of onset or pre-transfusion hematocrit levels.
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Sonnet P, Mullié C. In vitro antimalarial activity of ICL670: a further proof of the correlation between inhibition of β-hematin formation and of peroxidative degradation of hemin. Exp Parasitol 2011; 128:26-31. [PMID: 21295029 DOI: 10.1016/j.exppara.2011.01.018] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2010] [Revised: 01/24/2011] [Accepted: 01/28/2011] [Indexed: 10/18/2022]
Abstract
Iron chelators such as deferiprone, deferoxamine (DFO) and ICL670 (deferasirox) have previously been shown to display in vitro and/or in vivo antimalarial activities. To gain further insight in their antimalarial mechanism of action, their activities on inhibition of β-hematin formation and on both peroxidative and glutathione (GSH)-mediated degradation of hemin were investigated. Neither deferiprone nor DFO were able to inhibit β-hematin formation while ICL670 activity nearly matched that of chloroquine (CQ). Peroxidative degradation of hemin was also only strongly inhibited by both CQ and ICL670, the latter being significantly more efficient at pH 5.2. All iron chelators displayed minor, if any, inhibitory activity on GSH-mediated degradation of hemin. Discrepancies in the results obtained for the three iron chelators show that iron chelation is not the main driving force behind interference with heme degradation. Deferiprone, DFO and ICL670 share little structural community but both ICL670 and antimalarial ursolic acid derivatives (previously shown to block β-hematin formation and the peroxidative degradation of hemin) have hydrophobic groups and hydroxyphenyl moieties. These similarities in structures and activities further back up a possible two-step mechanism of action previously proposed for ursolic acid derivatives (Mullié et al., 2010) implying (1) stacking of an hydrophobic structure to hemin and (2) additive protection of hemin ferric iron from H(2)O(2) by hydroxyphenyl groups through steric hindrance and/or trapping of oxygen reactive species in the direct neighborhood of ferric iron. These peculiar antimalarial mechanisms of action for ICL670 warrant further investigations and development.
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Baek JH, Reiter CEN, Manalo DJ, Buehler PW, Hider RC, Alayash AI. Induction of hypoxia inducible factor (HIF-1α) in rat kidneys by iron chelation with the hydroxypyridinone, CP94. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2011; 1809:262-8. [PMID: 21558026 DOI: 10.1016/j.bbagrm.2011.04.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Revised: 04/19/2011] [Accepted: 04/22/2011] [Indexed: 11/19/2022]
Abstract
Hypoxia inducible factor (HIF-1α) is a master regulator of tissue adaptive responses to hypoxia whose stability is controlled by an iron containing prolyl hydroxylase domain (PHD) protein. A catalytic redox cycle in the PHD's iron center that results in the formation of a ferryl (Fe(+4)) intermediate has been reported to be responsible for the hydroxylation and subsequent degradation of HIF-1α under normoxia. We show that induction of HIF-1α in rat kidneys can be achieved by iron reduction by the hydroxypyridin-4 one (CP94), an iron chelator administered intraperitoneally in rats. The extent of HIF protein stabilization as well as the expression of HIF target genes, including erythropoietin (EPO), in kidney tissues was comparable to those induced by known inhibitors of the PHD enzyme, such as desferrioxamine (DFO) and cobalt chloride (CoCl(2)). In human kidney cells and in vitro PHD activity assay, we were able to show that the HIF-1α protein can be stabilized by addition of CP94. This appears to inactivate PHD; and thus prevents the hydroxylation of HIF-1α. In conclusion, we have identified the inhibition of iron-binding pocket of PHD as an underlying mechanism of HIF induction in vivo and in vitro by a bidentate hydroxypyridinone.
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Vlachodimitropoulou E, Sharp PA, Naftalin RJ. Quercetin-iron chelates are transported via glucose transporters. Free Radic Biol Med 2011; 50:934-44. [PMID: 21238582 DOI: 10.1016/j.freeradbiomed.2011.01.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 12/31/2010] [Accepted: 01/06/2011] [Indexed: 10/18/2022]
Abstract
Flavonoids are well-known antioxidants and free radical scavengers. Their metal-binding activity suggests that they could be effective protective agents in pathological conditions caused by both extracellular and intracellular oxidative stress linked to metal overload. Quercetin is both a permeant ligand via glucose transport proteins (GLUTs) and a high-affinity inhibitor of GLUT-mediated glucose transport. Chelatable "free iron" at micromolar concentrations in body fluids is a catalyst of hydroxyl radical (OH(•)) production from hydrogen peroxide. A number of flavonoids, e.g., quercetin, luteolin, chrysin, and 3,6-dihydroxyflavone, have been demonstrated to chelate intracellular iron and suppress OH(•) radical production in Madin Darby canine kidney cells. The most effective chelation comes from the flavonone B ring catechol found in both quercetin and luteolin. We show here that quercetin concentrations of <1μM can facilitate chelatable iron shuttling via GLUT1 in either direction across the cell membrane. These siderophoric effects are inhibited by raised quercetin concentrations (>1μM) or GLUT inhibitors, e.g., phloretin or cytochalasin B, and iron efflux is enhanced by impermeant extracellular iron chelators, either desferrioxamine or rutin. This iron shuttling property of quercetin might be usefully harnessed in chelotherapy of iron-overload conditions.
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Inati A, Khoriaty E, Musallam KM, Taher AT. Iron chelation therapy for patients with sickle cell disease and iron overload. Am J Hematol 2010; 85:782-6. [PMID: 20721892 DOI: 10.1002/ajh.21806] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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Evans P, Kayyali R, Hider RC, Eccleston J, Porter JB. Mechanisms for the shuttling of plasma non-transferrin-bound iron (NTBI) onto deferoxamine by deferiprone. Transl Res 2010; 156:55-67. [PMID: 20627190 PMCID: PMC2927975 DOI: 10.1016/j.trsl.2010.05.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Revised: 04/29/2010] [Accepted: 05/01/2010] [Indexed: 01/19/2023]
Abstract
In iron overload conditions, plasma contains non-transferrin bound iron species, collectively referred to as plasma NTBI. These include iron citrate species, some of which are protein bound. Because NTBI is taken into tissues susceptible to iron loading, its removal by chelation is desirable but only partial using standard deferoxamine (DFO) therapy. Speciation plots suggest that, at clinically achievable concentrations, deferiprone (DFP) will shuttle iron onto DFO to form feroxamine (FO), but whether NTBI chelation by DFO is enhanced to therapeutically relevant rates by DFP is unknown. As FO is highly stable, kinetic measurements of FO formation by high-performance liquid chromatography or by stopped-flow spectrometry are achievable. In serum from thalassemia major patients supplemented with 10 microM DFO, FO formation paralleled NTBI removal but never exceeded 50% of potentially available NTBI; approximately one third of NTBI was chelated rapidly but only 15% of the remainder at 20 h. Addition of DFP increased the magnitude of the slower component, with increments in FO formation equivalent to complete NTBI removal by 8 h. This shuttling effect was absent in serum from healthy control subjects, indicating no transferrin iron removal. Studies with iron citrate solutions also showed biphasic chelation by DFO, the slow component being accelerated by the addition of DFP, with optimal enhancement at 30 microM. Physiological concentrations of albumin also enhanced DFO chelation from iron citrate, and the co-addition of DFP further accelerated this effect. We conclude that at clinically relevant concentrations, DFP enhances plasma NTBI chelation with DFO by rapidly accessing and shuttling NTBI fractions that are otherwise only slowly available to DFO.
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Lu J, Gong D, Choong SY, Xu H, Chan YK, Chen X, Fitzpatrick S, Glyn-Jones S, Zhang S, Nakamura T, Ruggiero K, Obolonkin V, Poppitt SD, Phillips ARJ, Cooper GJS. Copper(II)-selective chelation improves function and antioxidant defences in cardiovascular tissues of rats as a model of diabetes: comparisons between triethylenetetramine and three less copper-selective transition-metal-targeted treatments. Diabetologia 2010; 53:1217-26. [PMID: 20221822 DOI: 10.1007/s00125-010-1698-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 01/22/2010] [Indexed: 12/26/2022]
Abstract
AIMS/HYPOTHESIS Treatment with the Cu(II)-selective chelator triethylenetetramine (TETA) improves cardiovascular disease in human patients, and cardiac and vascular/renal disease in rats used as a model of diabetes. Here we tested two hypotheses: first, that TETA elicits greater improvement in organ function than less Cu-selective transition-metal-targeted treatments; second, that the therapeutic actions of TETA are consistent with mediation through suppression of oxidative stress. METHODS Rats were made diabetic with streptozotocin (55 mg/kg, i. v.) and treated from 8 weeks after disease induction for the following 8 weeks with effective dosages of oral TETA, or one of three less Cu-selective transition-metal-targeted treatments: D-penicillamine, deferiprone or Zn acetate. Treatment effects were measured in ex vivo cardiac and aortic tissues, plasma and urine. RESULTS Diabetes damaged both cardiac and renal/vascular function by impairing the ability of cardiac output to respond physiologically to rising afterload, and by significantly elevating the urinary albumin/creatinine ratio. Diabetes also lowered total antioxidant potential and heparan sulphate levels in cardiac and arterial tissues, and serum ferroxidase activity, whereas it elevated urinary heparan sulphate excretion. TETA treatment rectified or partially rectified all these defects, whereas the other three experimental treatments were ineffectual. By contrast, none of the four drug treatments lowered diabetes-mediated elevations of plasma glucose or lipid concentrations. CONCLUSIONS/INTERPRETATION TETA may limit the cardiac and renal/vascular damage inflicted by diabetes through its actions to reinforce antioxidant defence mechanisms, probably acting through selective chelation of 'loosely-bound'/chelatable Cu(II). It may also improve heparan sulphate homeostasis and bolster antioxidant defence by increasing vascular extracellular superoxide dismutase activity. Urinary albumin/creatinine ratio might prove useful for monitoring TETA treatment.
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Balocco M, Carrara P, Pinto V, Forni GL. Daily alternating deferasirox and deferiprone therapy for "hard-to-chelate" beta-thalassemia major patients. Am J Hematol 2010; 85:460-1. [PMID: 20513129 DOI: 10.1002/ajh.21711] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Kolnagou A, Kontoghiorghes GJ. New golden era of chelation therapy in thalassaemia: the achievement and maintenance of normal range body iron stores. Br J Haematol 2010. [PMID: 20507309 DOI: 10.1111/j.1365-2141.2010.08229] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Kolnagou A, Kontoghiorghes GJ. New golden era of chelation therapy in thalassaemia: the achievement and maintenance of normal range body iron stores. Br J Haematol 2010; 150:489-90; author reply 491. [PMID: 20507309 DOI: 10.1111/j.1365-2141.2010.08229.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Agouzal M, Quyou A, Benchekroune K, Khattab M. [Epidemiological and economic aspects of chelating therapy in the therapeutic center of thalassemia in Morocco]. REVUE MEDICALE DE BRUXELLES 2010; 31:79-87. [PMID: 20677662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The study aims to give a general idea about the new experience of chelating drugs among beta-thalassemia patients. It is a declarative survey. It was done in the therapy center of Morocco. Statistics were done in the Laboratory of Biological Essays in Kenitra. All economic and pharmacological data were given by Novartis. Sample size was 89. The only treatment available now in the therapy center is deferiprone. 78% of patients attending the service regularly take deferiprone as treatment while 13% of them combine deferiprone and deferoxamine. Most of the patients take treatments regularly. Chelators have reduced mortality. Patients taking deferoxamine experienced injection site reactions. Most of ADR due to deferiprone were digestive. In conclusion, the main problem with chelators in Morocco is lack of accessibility to drugs (except for some patients insured or payant).
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Economou M, Printza N, Teli A, Tzimouli V, Tsatra I, Papachristou F, Athanassiou-Metaxa M. Renal dysfunction in patients with beta-thalassemia major receiving iron chelation therapy either with deferoxamine and deferiprone or with deferasirox. Acta Haematol 2010; 123:148-52. [PMID: 20185899 DOI: 10.1159/000287238] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2009] [Accepted: 12/22/2009] [Indexed: 01/18/2023]
Abstract
There are limited studies on renal involvement in beta-thalassemia, mainly involving patients on deferoxamine, reporting both glomerular and tubular dysfunction. The aim of the present study was to investigate renal involvement in young thalassemia patients, using both conventional and early markers of renal dysfunction, and to correlate findings to iron chelation therapy. Forty-two patients aged 4-23 years were studied and, for analysis purposes, were divided into two groups based on chelation therapy (group A receiving deferasirox and group B receiving deferoxamine and deferiprone combination therapy). In addition to conventional renal biochemistries, creatinine clearance, estimated glomerular filtration rate, serum cystatin C (Cys C), fractional excretion of sodium, tubular phosphorus reabsorption and urine calcium, protein, beta(2)-microglobulin (beta(2)-MG) and glucose levels were measured. A considerable number of patients demonstrated impaired renal function with elevated Cys C levels (36%), glomerular dysfunction with proteinuria (24%) and tubulopathy with hypercalciuria (35.5%) and elevated excretion of beta(2)-MG (33.5%). Renal involvement seems to be present even in young patients with beta-thalassemia, therefore, routine use of early markers of renal dysfunction is recommended. Further studies are needed in order to investigate the role of new chelators in tubular function parameters.
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Gaboriau F, Leray AM, Ropert M, Gouffier L, Cannie I, Troadec MB, Loréal O, Brissot P, Lescoat G. Effects of deferasirox and deferiprone on cellular iron load in the human hepatoma cell line HepaRG. Biometals 2009; 23:231-45. [PMID: 19997770 DOI: 10.1007/s10534-009-9281-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 11/28/2009] [Indexed: 12/14/2022]
Abstract
Two oral chelators, CP20 (deferiprone) and ICL670 (deferasirox), have been synthesized for the purpose of treating iron overload diseases, especially thalassemias. Given their antiproliferative effects resulting from the essential role played by iron in cell processes, such compounds might also be useful as anticancer agents. In the present study, we tested the impact of these two iron chelators on iron metabolism, in the HepaRG cell line which allowed us to study proliferating and differentiated hepatocytes. ICL670 uptake was greater than the CP20 uptake. The iron depletion induced by ICL670 in differentiated cells increased soluble transferrin receptor expression, decreased intracellular ferritin expression, inhibited (55)Fe (III) uptake, and reduced the hepatocyte concentration of the labile iron pool. In contrast, CP20 induced an unexpected slight increase in intracellular ferritin, which was amplified by iron-treated chelator exposure. CP20 also promoted Fe(III) uptake in differentiated HepaRG cells, thus leading to an increase of both the labile pool and storage forms of iron evaluated by calcein fluorescence and Perls staining, respectively. In acellular conditions, compared to CP20, iron removing ability from the calcein-Fe(III) complex was 40 times higher for ICL670. On the whole, biological responses of HepaRG cells to ICL670 treatment were characteristic of expected iron depletion. In contrast, the effects of CP20 suggest the potential involvement of this compound in the iron uptake from the external medium into the hepatocytes from the HepaRG cell line, therefore acting like a siderophore in this cell model.
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Prus E, Fibach E. Effect of iron chelators on labile iron and oxidative status of thalassaemic erythroid cells. Acta Haematol 2009; 123:14-20. [PMID: 19923794 DOI: 10.1159/000258958] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Accepted: 09/23/2009] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Iron accumulation in vital organs such as heart and liver is a major pathology in beta-thalassaemia. It may also affect mature RBCs and developing erythroid precursors. The cellular damage is mainly caused by the labile iron pool (LIP) and is mediated by reactive oxygen species (ROS). We have previously shown that thalassaemic RBCs and their precursors have more LIP and ROS than their normal counterparts. We now report the effect of clinically relevant iron chelators on these parameters. METHODS RBCs, reticulocytes and cultured erythroid precursors derived from patients with beta-thalassaemia were studied for LIP and oxidative stress parameters by flow-cytometry. RESULTS In vitro treatment with deferiprone, deferasirox and deferoxamine reduced the cytosolic LIP in RBCs and reticulocytes, and both the cytosolic and mitochondrial LIP in cultured erythroid precursors. This was associated with reduced oxidative stress (ROS and external phosphatidylserine). While the effect of deferiprone and deferasirox was fast (within 10 min), deferoxamine affected these parameters after 24 h, suggesting a slower rate of entry. CONCLUSION The chelators studied reduce the LIP and the oxidative status of thalassaemic RBC and their precursors. Whether these effects directly improve ineffective erythropoiesis and RBC survival remains to be shown.
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Abstract
Iron overload is one of the major causes of morbidity in patients with thalassemia major. Deferiprone (DFP), an orally active iron chelator, emerged from an extensive search for new drugs to treat iron overload. Comparative studies have shown that at comparable doses the efficacy of DFP in removing body iron is similar to that of desferoxamine (DFO). In retrospective and prospective studies, DFP monotherapy was significantly more effective than DFO in the treatment of myocardial siderosis in thalassemia major. DFP can be used in combination with DFO in the management of severe iron overload. This chelation regimen is tolerable and attractive for patients unable to comply with standard DFO infusions or with inadequate response to DFP monotherapy. DFP has a well-known long-term safety profile. Agranulocytosis is the most serious side effect associated with its use, occurring in about 1% of the patients. More common but less serious side effects are gastrointestinal symptoms, arthralgia, zinc deficiency, and fluctuating transaminase levels.
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Hoque M, Hanauske-Abel HM, Palumbo P, Saxena D, D'Alliessi Gandolfi D, Park MH, Pe'ery T, Mathews MB. Inhibition of HIV-1 gene expression by Ciclopirox and Deferiprone, drugs that prevent hypusination of eukaryotic initiation factor 5A. Retrovirology 2009; 6:90. [PMID: 19825182 PMCID: PMC2770518 DOI: 10.1186/1742-4690-6-90] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Accepted: 10/13/2009] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Eukaryotic translation initiation factor eIF5A has been implicated in HIV-1 replication. This protein contains the apparently unique amino acid hypusine that is formed by the post-translational modification of a lysine residue catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase (DOHH). DOHH activity is inhibited by two clinically used drugs, the topical fungicide ciclopirox and the systemic medicinal iron chelator deferiprone. Deferiprone has been reported to inhibit HIV-1 replication in tissue culture. RESULTS Ciclopirox and deferiprone blocked HIV-1 replication in PBMCs. To examine the underlying mechanisms, we investigated the action of the drugs on eIF5A modification and HIV-1 gene expression in model systems. At early times after drug exposure, both drugs inhibited substrate binding to DOHH and prevented the formation of mature eIF5A. Viral gene expression from HIV-1 molecular clones was suppressed at the RNA level independently of all viral genes. The inhibition was specific for the viral promoter and occurred at the level of HIV-1 transcription initiation. Partial knockdown of eIF5A-1 by siRNA led to inhibition of HIV-1 gene expression that was non-additive with drug action. These data support the importance of eIF5A and hypusine formation in HIV-1 gene expression. CONCLUSION At clinically relevant concentrations, two widely used drugs blocked HIV-1 replication ex vivo. They specifically inhibited expression from the HIV-1 promoter at the level of transcription initiation. Both drugs interfered with the hydroxylation step in the hypusine modification of eIF5A. These results have profound implications for the potential therapeutic use of these drugs as antiretrovirals and for the development of optimized analogs.
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100
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Telfer PT, Warburton F, Christou S, Hadjigavriel M, Sitarou M, Kolnagou A, Angastiniotis M. Improved survival in thalassemia major patients on switching from desferrioxamine to combined chelation therapy with desferrioxamine and deferiprone. Haematologica 2009; 94:1777-8. [PMID: 19815834 DOI: 10.3324/haematol.2009.009118] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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