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The Cochrane Database of Systematic... May 2018Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia (who are transfusion-dependent or non-transfusion-dependent) are at risk of iron... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia (who are transfusion-dependent or non-transfusion-dependent) are at risk of iron overload. Iron overload can lead to iron toxicity in vulnerable organs such as the heart, liver and endocrine glands; which can be prevented and treated with iron chelating agents. The intensive demands and uncomfortable side effects of therapy can have a negative impact on daily activities and well-being, which may affect adherence.
OBJECTIVES
To identify and assess the effectiveness of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions) to improve adherence to iron chelation therapy in people with SCD or thalassaemia.
SEARCH METHODS
We searched CENTRAL (the Cochrane Library), MEDLINE, Embase, CINAHL, PsycINFO, Psychology and Behavioral Sciences Collection, Web of Science Science & Social Sciences Conference Proceedings Indexes and ongoing trial databases (01 February 2017). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register (12 December 2017).
SELECTION CRITERIA
For trials comparing medications or medication changes, only randomised controlled trials (RCTs) were eligible for inclusion.For studies including psychological and psychosocial interventions, educational Interventions, or multi-component interventions, non-RCTs, controlled before-after studies, and interrupted time series studies with adherence as a primary outcome were also eligible for inclusion.
DATA COLLECTION AND ANALYSIS
Three authors independently assessed trial eligibility, risk of bias and extracted data. The quality of the evidence was assessed using GRADE.
MAIN RESULTS
We included 16 RCTs (1525 participants) published between 1997 and 2017. Most participants had β-thalassaemia major; 195 had SCD and 88 had β-thalassaemia intermedia. Mean age ranged from 11 to 41 years. One trial was of medication management and 15 RCTs were of medication interventions. Medications assessed were subcutaneous deferoxamine, and two oral-chelating agents, deferiprone and deferasirox.We rated the quality of evidence as low to very low across all outcomes identified in this review.Three trials measured quality of life (QoL) with validated instruments, but provided no analysable data and reported no difference in QoL.Deferiprone versus deferoxamineWe are uncertain whether deferiprone increases adherence to iron chelation therapy (four trials, very low-quality evidence). Results could not be combined due to considerable heterogeneity (participants' age and different medication regimens). Medication adherence was high (deferiprone (85% to 94.9%); deferoxamine (71.6% to 93%)).We are uncertain whether deferiprone increases the risk of agranulocytosis, risk ratio (RR) 7.88 (99% confidence interval (CI) 0.18 to 352.39); or has any effect on all-cause mortality, RR 0.44 (95% CI 0.12 to 1.63) (one trial; 88 participants; very low-quality evidence).Deferasirox versus deferoxamineWe are uncertain whether deferasirox increases adherence to iron chelation therapy, mean difference (MD) -1.40 (95% CI -3.66 to 0.86) (one trial; 197 participants; very-low quality evidence). Medication adherence was high (deferasirox (99%); deferoxamine (100%)). We are uncertain whether deferasirox decreases the risk of thalassaemia-related serious adverse events (SAEs), RR 0.95 (95% CI 0.41 to 2.17); or all-cause mortality, RR 0.96 (95% CI 0.06 to 15.06) (two trials; 240 participants; very low-quality evidence).We are uncertain whether deferasirox decreases the risk of SCD-related pain crises, RR 1.05 (95% CI 0.68 to 1.62); or other SCD-related SAEs, RR 1.08 (95% CI 0.77 to 1.51) (one trial; 195 participants; very low-quality evidence).Deferasirox film-coated tablet (FCT) versus deferasirox dispersible tablet (DT)Deferasirox FCT may make little or no difference to adherence, RR 1.10 (95% CI 0.99 to 1.22) (one trial; 173 participants; low-quality evidence). Medication adherence was high (FCT (92.9%); DT (85.3%)).We are uncertain if deferasirox FCT increases the incidence of SAEs, RR 1.22 (95% CI 0.62 to 2.37); or all-cause mortality, RR 2.97 (95% CI 0.12 to 71.81) (one trial; 173 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferiprone alone We are uncertain if deferiprone and deferoxamine combined increases adherence to iron chelation therapy (very low-quality evidence). Medication adherence was high (deferiprone 92.7% (range 37% to 100%) to 93.6% (range 56% to 100%); deferoxamine 70.6% (range 25% to 100%).Combination therapy may make little or no difference to the risk of SAEs, RR 0.15 (95% CI 0.01 to 2.81) (one trial; 213 participants; low-quality evidence).We are uncertain if combination therapy decreases all-cause mortality, RR 0.77 (95% CI 0.18 to 3.35) (two trials; 237 participants; very low-quality evidence).Deferiprone and deferoxamine combined versus deferoxamine aloneDeferiprone and deferoxamine combined may have little or no effect on adherence to iron chelation therapy (four trials; 216 participants; low-quality evidence). Medication adherence was high (deferoxamine 91.4% to 96.1%; deferiprone: 82.4%)Deferiprone and deferoxamine combined, may have little or no difference in SAEs or mortality (low-quality evidence). No SAEs occurred in three trials and were not reported in one trial. No deaths occurred in two trials and were not reported in two trials.Deferiprone and deferoxamine combined versus deferiprone and deferasirox combinedDeferiprone and deferasirox combined may improve adherence to iron chelation therapy, RR 0.84 (95% CI 0.72 to 0.99) (one trial; 96 participants; low-quality evidence). Medication adherence was high (deferiprone and deferoxamine: 80%; deferiprone and deferasirox: 95%).We are uncertain if deferiprone and deferasirox decreases the incidence of SAEs, RR 1.00 (95% CI 0.06 to 15.53) (one trial; 96 participants; very low-quality evidence).There were no deaths in the trial (low-quality evidence).Medication management versus standard careWe are uncertain if medication management improves health-related QoL (one trial; 48 participants; very low-quality evidence). Adherence was only measured in one arm of the trial.
AUTHORS' CONCLUSIONS
The medication comparisons included in this review had higher than average adherence rates not accounted for by differences in medication administration or side effects.Participants may have been selected based on higher adherence to trial medications at baseline. Also, within the clinical trial context, there is increased attention and involvement of clinicians, thus high adherence rates may be an artefact of trial participation.Real-world, pragmatic trials in community and clinic settings are needed that examine both confirmed or unconfirmed adherence strategies that may increase adherence to iron chelation therapy.Due to lack of evidence this review cannot comment on intervention strategies for different age groups.
Topics: Adolescent; Adult; Anemia, Sickle Cell; Benzoates; Chelation Therapy; Child; Deferasirox; Deferiprone; Deferoxamine; Humans; Iron Chelating Agents; Iron Overload; Patient Compliance; Pyridones; Quality of Life; Randomized Controlled Trials as Topic; Triazoles; beta-Thalassemia
PubMed: 29737522
DOI: 10.1002/14651858.CD012349.pub2 -
The Cochrane Database of Systematic... Feb 2012Thalassemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Thalassemia is a hereditary anaemia due to ineffective erythropoiesis. In particular, people with thalassaemia major develop secondary iron overload resulting from regular red blood cell transfusion. Iron chelation therapy is needed to prevent long-term complications.Both deferoxamine and deferiprone have been found to be efficacious. However, a systematic review of the effectiveness and safety of the new oral chelator deferasirox in people with thalassaemia is needed.
OBJECTIVES
To assess the effectiveness and safety of oral deferasirox in people with thalassaemia and secondary iron overload.
SEARCH METHODS
We searched the Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register. We also searched MEDLINE, EMBASE, EBMR, Biosis Previews, Web of Science, Derwent Drug File, XTOXLINE and three trial registries: www.controlled-trials.com; www.clinicaltrials.gov; www.who.int./ictrp/en/. Date of the most recent searches of these databases: 24 June 2010.Date of the most recent search of the Group's Haemoglobinopathies Trials Register: 03 November 2011.
SELECTION CRITERIA
Randomised controlled trials 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
Four studies met the inclusion criteria.Two studies compared deferasirox to placebo or standard therapy of deferoxamine (n = 47). The placebo-controlled studies, a pharmacokinetic and a dose escalation study, showed that deferasirox leads to net iron excretion in transfusion-dependent thalassaemia patients. In these studies, safety was acceptable and further investigation in phase II and phase III trials was warranted.Two studies, one phase II study (n = 71) and one phase III study (n = 586) compared deferasirox to 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 trial, similar or superior efficacy for surrogate parameters of ferritin and liver iron concentration 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/d and 51.6 mg/d respectively. Data on safety at the presumably required doses for effective chelation therapy are limited. Patient satisfaction was significantly better with deferasirox, while rate of discontinuations was similar for both drugs.
AUTHORS' CONCLUSIONS
Deferasirox offers an important alternative line of treatment 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 in the long run and will translate to similar benefits as has been shown for deferoxamine, needs to be confirmed. Data on safety, particularly on rare toxicities and long-term safety, are still limited.Therefore, we think that deferasirox should be offered as an alternative to all patients with thalassaemia who either show intolerance to deferoxamine or poor compliance with deferoxamine. In our opinion, data are still too limited to support the general recommendation of deferasirox as first-line treatment instead of deferoxamine. If a strong preference for deferasirox is expressed, it could be offered as first-line option to individual patients after a detailed discussion of the potential benefits and risks.
Topics: Benzoates; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Deferasirox; Deferoxamine; Erythrocyte Transfusion; Humans; Iron Chelating Agents; Iron Overload; Randomized Controlled Trials as Topic; Thalassemia; Triazoles
PubMed: 22336831
DOI: 10.1002/14651858.CD007476.pub2 -
Blood Cells, Molecules & Diseases Oct 2011The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences... (Meta-Analysis)
Meta-Analysis Review
The effectiveness of deferoxamine (DFO), deferiprone (DFP), or deferasirox (DFX) in thalassemia major was assessed. Outcomes were reported as means±SD, mean differences with 95% CI, or standardized mean differences. Statistical heterogeneity was tested using χ2 (Q) and I2. Sources of bias and Grading of Recommendations Assessment, Development and Evaluation system (GRADE) were considered. Overall, 1520 patients were included. Only 7.4% of trials were free of bias. Overall measurements suggest low trial quality (GRADE). The meta-analysis suggests lower final liver iron concentrations during associated versus monotherapy treatment (p<0.0001), increases in serum ferritin levels during DFX 5, 10, and 20 mg/kg versus DFO-treated groups (p<0.00001, p<0.00001, and p=0.002, respectively), but no statistically significant difference during DFX 30 mg/kg versus DFO (p=0.70), no statistically significant variations in heart T2* signal during associated or sequential versus mono-therapy treatment (p=0.46 and p=0.14, respectively), increases in urinary iron excretion during associated or sequential versus monotherapy treatment (p=0.008 and p=0.02, respectively), and improved ejection fraction during associated or sequential versus monotherapy treatment (p=0.01 and p<0.00001, respectively). These findings do not support any specific chelation treatment. The literature shows risks of bias, and additional larger and longer trials are needed.
Topics: Benzoates; Chelation Therapy; Deferasirox; Deferiprone; Deferoxamine; Drug Therapy, Combination; Ferritins; Humans; Iron; Iron Chelating Agents; Liver; MEDLINE; Myocardium; Pyridones; Randomized Controlled Trials as Topic; Siderophores; Treatment Outcome; Triazoles; Ventricular Function; beta-Thalassemia
PubMed: 21843958
DOI: 10.1016/j.bcmd.2011.07.002 -
The Cochrane Database of Systematic... 2003Researchers are exploring the effects of adding treatments to the main antimalarial regimens in an attempt to reduce mortality from Plasmodium falciparum. Iron chelation... (Review)
Review
BACKGROUND
Researchers are exploring the effects of adding treatments to the main antimalarial regimens in an attempt to reduce mortality from Plasmodium falciparum. Iron chelation is one potential chemotherapeutic adjuvant treatment. Before advocating adjunctive therapy, the effects of iron chelators in improving patient outcomes need to be examined.
OBJECTIVES
To assess the effects of iron-chelating agents combined with antimalarial drugs, or iron chelators alone, for treating Plasmodium falciparum malaria in adults and children, in relation to mortality, coma recovery time, parasite clearance, and adverse effects.
SEARCH STRATEGY
We searched the Cochrane Infectious Diseases Group trials register (up to January 2003), the Cochrane Central Register of Controlled Trials (Cochrane Library, Issue 1, 2003), MEDLINE (January 1966 to January 2003), EMBASE (January 1980 to November 2002), and reference lists of retrieved studies. We also contacted organisations, experts and researchers in the field.
SELECTION CRITERIA
All randomised controlled trials comparing iron chelating agents with placebo, or comparing iron chelating agents in conjunction with other antimalarials with antimalarial treatment alone in adults or children with falciparum malaria.
DATA COLLECTION AND ANALYSIS
Two reviewers independently applied inclusion criteria and assessed trial quality. One reviewer (HS) extracted data from included studies. Study authors were contacted for missing and additional data.
MAIN RESULTS
Seven trials involving 570 participants were included. Two trials involving 435 children compared the iron chelator DFO with placebo and standard treatment. No evidence of benefit or harm was shown in relation to mortality, but studies were small. The risk of experiencing persistent seizures was lower with DFO compared to placebo treatment (RR 0.80, 95% CI 0.67 to 0.95), but adverse effects were more common in the DFO group. One trial involving 45 adults and children compared the orally active iron chelator (deferiprone) with placebo and standard treatment; coma recovery (WMD -27 hrs; 95%CI -34.20 to -19.80) and parasite clearance (WMD -24 hrs; 95%CI -35.27 to -12.73) were significantly faster in the deferiprone group compared to placebo, but clinical significance cannot be assumed from this small trial. The authors reported no side effects during the study.
REVIEWER'S CONCLUSIONS
There are insufficient data for any conclusions for both agents tested. There are non-significant trends towards harm (death) and potential benefit (fewer seizures) with DFO. With deferiprone, results suggest possible benefit (shorter coma recovery and parasite clearance). If this topic is considered a priority for further research, larger trials are needed to detect an effect on clinical outcomes; and these trials should also include carefully evaluate adverse effects.
Topics: Adult; Antimalarials; Chemotherapy, Adjuvant; Child; Humans; Iron Chelating Agents; Malaria, Cerebral; Malaria, Falciparum; Randomized Controlled Trials as Topic
PubMed: 12804409
DOI: 10.1002/14651858.CD001474 -
BMC Blood Disorders Nov 2002BACKGROUND: Beta thalassemia major requires regular blood transfusions and iron chelation to alleviate the harmful accumulation of iron. Evidence on the efficacy and...
Estimates of the effect on hepatic iron of oral deferiprone compared with subcutaneous desferrioxamine for treatment of iron overload in thalassemia major: a systematic review.
BACKGROUND: Beta thalassemia major requires regular blood transfusions and iron chelation to alleviate the harmful accumulation of iron. Evidence on the efficacy and safety of the available agents, desferrioxamine and deferiprone, is derived from small, non-comparative, heterogeneous observational studies. This evidence was reviewed to quantitatively compare the ability of these chelators to reduce hepatic iron. METHODS: The literature was searched using Medline and all reports addressing the effect of either chelator on hepatic iron were considered. Data were abstracted independently by two investigators. Analyses were performed using reported individual patient data. Hepatic iron concentrations at study end and changes over time were compared using ANCOVA, controlling for initial iron load. Differences in the proportions of patients improving were tested using chi2. RESULTS: Eight of 11 reports identified provided patient-level data relating to 30 desferrioxamine- and 68 deferiprone-treated patients. Desferrioxamine was more likely than optimal dose deferiprone to decrease hepatic iron over the average follow-up of 45 months (odds ratio, 19.0, 95% CI, 2.4 to 151.4). The degree of improvement was also larger with desferrioxamine. CONCLUSIONS: This analysis suggests that desferrioxamine is more effective than deferiprone in lowering hepatic iron. This comparative analysis - despite its limitations - should prove beneficial to physicians faced with the challenge of selecting the optimal treatment for their patients.
PubMed: 12441006
DOI: 10.1186/1471-2326-2-4