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1.
Furosemide and albumin for the treatment of nephrotic edema: a systematic review
Hedin E, Bijelić V, Barrowman N, Geier P
Pediatric nephrology (Berlin, Germany). 2022
Abstract
BACKGROUND Edema is one of the cardinal clinical features of nephrotic syndrome (NS). It may vary from mild periorbital edema to severe generalized edema (anasarca). In patients where edema does not improve with prednisone therapy, the most common supportive medications are diuretics and albumin. However, due to the complex pathophysiology of edema formation in NS patients resulting in intravascular normovolemia or hypovolemia, optimal therapy for edema is still debated. We conducted a systematic review with the objective of evaluating the change in urine volume and urine sodium excretion after treatment with furosemide only versus furosemide with albumin in edematous patients with NS. OBJECTIVES (1) To evaluate efficacy of furosemide alone versus furosemide with albumin in the treatment of nephrotic edema in adults and children. (2) To compare the harms and benefits of different doses of furosemide for treating nephrotic edema. SEARCH METHODS The search included all randomized or quasi-randomized controlled trials in English and French using MEDLINE, Embase, and CENTRAL Trials Registry of the Cochrane Collaboration using the Ovid interface. ClinicalTrials.gov and the International Clinical Trials Registry Platform were also searched. SELECTION CRITERIA We included all RCTs and randomized cross-over studies in which furosemide and furosemide plus albumin are used in the treatment of children or adults with nephrotic edema. We excluded patients with hypoalbuminemia of non-renal origin and severe chronic kidney disease (CKD) with a glomerular filtration rate below 30 ml/min/1.74 m(2) and patients with congenital NS. DATA COLLECTION AND ANALYSIS All abstracts were independently assessed by at least two authors to determine which studies met the inclusion criteria. Information on study design, methodology, and outcome data (urine volume, urine sodium excretion, adverse effects) from each identified study was entered into a separate data sheet. The differences in outcomes between the types of therapy were expressed as standardized mean difference (SMD) with 95% confidence intervals (CI). RESULTS The search yielded 525 records, and after screening, five studies were included in the systematic review and four of those studies in the meta-analysis. One study had high risk of bias and the remaining three studies were deemed to have some concerns. Urine excretion was greater after treatment with furosemide and albumin versus furosemide (SMD 0.85, 95% CI = 0.33 to 1.38). Results for sodium excretion were inconclusive (SMD 0.37, 95%CI = - 0.28 to 1.02). AUTHORS' CONCLUSIONS The current evidence is not sufficient to make definitive conclusions about the role of albumin in treating nephrotic edema. High-quality randomized studies with adequate samples sizes are needed. Including an assessment of intravascular volume status may be helpful. TRIAL REGISTRATION Prospero: CRD4201808979. https://www.crd.york.ac.uk/PROSPERO A higher resolution version of the Graphical abstract is available as Supplementary information.
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2.
Use of erythropoiesis-stimulating agents in children with chronic kidney disease: a systematic review
Bruce G, Schulga P, Reynolds BC
Clinical kidney journal. 2022;15(8):1483-1505
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Abstract
BACKGROUND Erythropoiesis-stimulating agents (ESAs) revolutionized the management of anaemia in chronic kidney disease (CKD) when introduced in the late 1980s. A range of ESA types, preparations and administration modalities now exist, with newer agents requiring less frequent administration. Although systematic reviews and meta-analyses have been published in adults, no systematic review has been conducted investigating ESAs in children. METHODS The Preferred Reporting Items for Systematic Reviews and Meta-analyses statement for the conduct of systematic reviews was used. All available literature on outcomes relating to ESAs in children with CKD was sought. A search of the MEDLINE, CINAHL and Embase databases was conducted by two independent reviewers. Inclusion criteria were published trials in English, children with chronic and end-stage kidney disease and use of any ESA studied against any outcome measure. An assessment of risk of bias was carried out in all included randomized trials using the criteria from the Cochrane Handbook for Systematic Reviews of Interventions. Two tables were used for data extraction for randomized and observational studies. Study type, participants, inclusion criteria, case characteristics, follow-up duration, ESA type and dosage, interventions and outcomes were extracted by one author. RESULTS Of 965 identified articles, 58 were included covering 54 cohorts. Six were randomized trials and 48 were observational studies. A total of 38 studies assessed the efficacy of recombinant human erythropoietin (rHuEPO), 11 of darbepoetin alpha (DA) and 3 of continuous erythropoietin receptor activator (CERA), with 6 studies appraising secondary outcome measures exclusively. Recruitment to studies was a consistent challenge. The most common adverse effect was hypertension, although confounding effects often limited direct correlation. Two large cohort studies demonstrated a greater hazard of death independently associated with high ESA dose. Secondary outcome measures included quality of life measures, growth and nutrition, exercise capacity, injection site pain, cardiovascular function, intelligent quotient, evoked potentials and platelet function. CONCLUSIONS All ESA preparations and modes of administration were efficacious, with evidence of harm at higher doses. Evidence supports individualizing treatments, with strong consideration given to alternate treatments in patients who appear resistant to ESA therapy. Further research should focus on randomized trials comparing the efficacy of different preparations, treatment options in apparently ESA-resistant cohorts and clarification of meaningful secondary outcomes to consolidate patient-relevant indices.
PICO Summary
Population
Children with chronic kidney disease using any erythropoiesis-stimulating agents (ESAs), (58 studies, n= 3,895).
Intervention
Systematic review assessing the efficacy of ESAs.
Comparison
Outcome
A total of 38 studies assessed the efficacy of recombinant human erythropoietin, 11 of darbepoetin alpha, and 3 of continuous erythropoietin receptor activator, with 6 studies appraising secondary outcome measures exclusively. The most common adverse effect was hypertension, although confounding effects often limited direct correlation. Two large cohort studies demonstrated a greater hazard of death independently associated with high ESA dose. Secondary outcome measures included quality of life measures, growth and nutrition, exercise capacity, injection site pain, cardiovascular function, intelligent quotient, evoked potentials and platelet function.
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Efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection for the treatment of renal anemia in Chinese hemodialysis patients: A randomized, open-label, parallel-group, noninferiority phase III trial
Liu B, Chen N, Zhao J, Yin A, Wu X, Xing C, Jiang G, Fu J, Wang M, Wang R, et al
Chronic diseases and translational medicine. 2022;8(2):134-144
Abstract
BACKGROUND This study was to explore the clinical efficacy and safety of darbepoetin alfa injection replacing epoetin alfa injection (recombinant human erythropoietin injection, rHuEPO) for the treatment of anemia associated with chronic kidney failure in Chinese patients undergoing hemodialysis. METHOD This study was a multicenter, randomized, open-label, intergroup parallel control phase III noninferiority trial from April 19, 2013 to September 9, 2014 at 25 sites. In this study, the members of the darbepoetin alfa group underwent intravenous administration once per week or once every two weeks. The members of the control drug epoetin alfa group underwent intravenous administration two or three times per week. All subjects underwent epoetin alfa administration during the 8-week baseline period. After that, subjects were randomly assigned to the darbepoetin alfa group or epoetin alfa group. The noninferiority in the changes of the average Hb concentrations from the baseline to the end of the evaluation period (noninferiority threshold: -1.0 g/dl) was tested between the two treatments. The time-dependent hemoglobin (Hb) concentration and the maintenance rate of the target Hb concentration (the proportion of subjects with Hb concentrations between 10.0 and 12.0 g/dl) were also evaluated. Iron metabolism, including changes in the serum iron, total iron-binding capacity, ferritin, transferrin saturation, and comparisons of the dose adjustments between the two groups during the treatment period were analyzed further. Adverse events (AEs) were also observed and compared, and the safety was analyzed between the two treatment groups. The conversion rate switching from epoetin alfa to darbepoetin alfa was also discussed. SAS® software version 9.2 was used to perform all statistical analyses. Descriptive statistics were used for all efficacy, safety, and demographic variable analyses, including for the primary efficacy indicators. RESULTS Four hundred and sixty-six patients were enrolled in this study, and ultimately 384 cases were analyzed for safety, including 267 cases in the darbepoetin alfa group and 117 cases in the epoetin alfa group. There were 211 cases in the per-protocol set, including 152 cases in the darbepoetin alfa group and 59 cases in the epoetin alfa group. The changes in the average Hb concentrations from the baseline to the end of the evaluation period were -0.07 and -0.15 g/dl in the darbepoetin alfa group and epoetin alfa group respectively. The difference between the two groups was 0.08 g/dl (95% confidence interval [CI]: -0.22 to 0.39), and the lower limit of the 95% CI was -0.22 > -1.0 g/dl. The average Hb concentrations of the two groups were 10.88-11.43 g/dl (darbepoetin alfa) and 10.91-11.38 g/dl (epoetin alfa) during the study period of Weeks 0-28, with the maintenance rates of the target Hb concentration ranging within 71%-87% and 78%-95% in the darbepoetin alfa group and epoetin alfa group respectively. During the period of comparison between the two groups, the incidence of AEs in the darbepoetin alfa group was 61.42%, while in the epoetin alfa group it was 56.41%. All of the adverse events and reactions in the study were those commonly associated with hemodialysis. CONCLUSION The overall efficacy and safety of darbepoetin alfa for the treatment of Chinese renal anemia patients undergoing hemodialysis are consistent with those of epoetin alfa.
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Comparison of darbepoetin alpha and recombinant human erythropoietin for treatment of anemia in pediatric chronic kidney disease: a non-inferiority trial from India
Mazahir R, Anand K, Pruthi PK
European journal of pediatrics. 2022
Abstract
To determine whether or not Darbepoetin alpha (DA) was non-inferior to recombinant human erythropoietin (rHuEPO) in the treatment of anemia in children with chronic kidney disease (CKD) stage 3-5 (on or not on dialysis). This was a randomized, open-label, two-arm, parallel group, active-controlled, non-inferiority trial conducted at a tertiary care center in New Delhi, India. Fifty patients of either gender (aged 1-18 years) with CKD stage 3-5 (on or not on dialysis) who had baseline hemoglobin (Hb) between 9 and 12 g/dL and were on stable erythropoietin therapy for at least 8 weeks were randomized (1:1) to either continue rHuEPO or switch to DA therapy for a period of 28 weeks. Doses were titrated in the initial 23 weeks to maintain the Hb between 11 and 12 g/dL, and efficacy was assessed between weeks 24 and 28. The primary efficacy outcome was the mean change in Hb between baseline and the evaluation period. In the intention-to-treat population (n = 50), the adjusted between-group difference in mean Hb change between the baseline and the evaluation period was 0.131 g/dL (95% CI: - 0.439 to 0.719, p = 0.629). The lower limit of the two-sided 95% CI for the difference in the mean change in Hb between the two treatment groups was well above the pre-specified non-inferiority margin of - 1.0 g/dL. Similar pattern of non-inferiority was seen for per protocol population. The safety profile of DA and rHuEPO was also comparable (injection site pain:rHuEPO-3, DA-7; p-0.296). Conclusion: DA is non-inferior to rHuEPO for the treatment of anemia of CKD (stage 3-5) in pediatric population with a comparable safety profile. Trial registration: ClinicalTrials.gov Identifier: NCT04959578 (retrospectively registered), Date: July 13, 2021. What is Known: • Limited studies showing darbepoetin alpha is effective in children as an erythropoiesis stimulating agent. • No RCT from Indian subcontinent addressing this topic. What is New: • Darbepoetin alpha is non inferior to recombinant human erythropoietin for treatment of anemia in children with CKD stage 3-5 (on or not on dialysis) with safety comparable to recombinant human erythropoietin. • A cost reduction of approximately 8.6% per patient by shifting to darbepoetin alpha.
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Parenteral versus oral iron therapy for adults and children with chronic kidney disease
O'Lone EL, Hodson EM, Nistor I, Bolignano D, Webster AC, Craig JC
The Cochrane database of systematic reviews. 2019;2:Cd007857
Abstract
BACKGROUND The anaemia seen in chronic kidney disease (CKD) may be exacerbated by iron deficiency. Iron can be provided through different routes, with advantages and drawbacks of each route. It remains unclear whether the potential harms and additional costs of intravenous (IV) compared with oral iron are justified. This is an update of a review first published in 2012. OBJECTIVES To determine the benefits and harms of IV iron supplementation compared with oral iron for anaemia in adults and children with CKD, including participants on dialysis, with kidney transplants and CKD not requiring dialysis. SEARCH METHODS We searched the Cochrane Kidney and Transplant Register of Studies up to 7 December 2018 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. SELECTION CRITERIA We included randomised controlled trials (RCTs) and quasi-RCTs in which IV and oral routes of iron administration were compared in adults and children with CKD. DATA COLLECTION AND ANALYSIS Two authors independently assessed study eligibility, risk of bias, and extracted data. Results were reported as risk ratios (RR) with 95% confidence intervals (CI) for dichotomous outcomes. For continuous outcomes the mean difference (MD) was used or standardised mean difference (SMD) if different scales had been used. Statistical analyses were performed using the random-effects model. Subgroup analysis and univariate meta-regression were performed to investigate between study differences. The certainty of the evidence was assessed using GRADE. MAIN RESULTS We included 39 studies (3852 participants), 11 of which were added in this update. A low risk of bias was attributed to 20 (51%) studies for sequence generation, 14 (36%) studies for allocation concealment, 22 (56%) studies for attrition bias and 20 (51%) for selective outcome reporting. All studies were at a high risk of performance bias. However, all studies were considered at low risk of detection bias because the primary outcome in all studies was laboratory-based and unlikely to be influenced by lack of blinding.There is insufficient evidence to suggest that IV iron compared with oral iron makes any difference to death (all causes) (11 studies, 1952 participants: RR 1.12, 95% CI 0.64, 1.94) (absolute effect: 33 participants per 1000 with IV iron versus 31 per 1000 with oral iron), the number of participants needing to start dialysis (4 studies, 743 participants: RR 0.81, 95% CI 0.41, 1.61) or the number needing blood transfusions (5 studies, 774 participants: RR 0.86, 95% CI 0.55, 1.34) (absolute effect: 87 per 1,000 with IV iron versus 101 per 1,000 with oral iron). These analyses were assessed as having low certainty evidence. It is uncertain whether IV iron compared with oral iron reduces cardiovascular death because the certainty of this evidence was very low (3 studies, 206 participants: RR 1.71, 95% CI 0.41 to 7.18). Quality of life was reported in five studies with four reporting no difference between treatment groups and one reporting improvement in participants treated with IV iron.IV iron compared with oral iron may increase the numbers of participants, who experience allergic reactions or hypotension (15 studies, 2607 participants: RR 3.56, 95% CI 1.88 to 6.74) (absolute harm: 24 per 1000 with IV iron versus 7 per 1000) but may reduce the number of participants with all gastrointestinal adverse effects (14 studies, 1986 participants: RR 0.47, 95% CI 0.33 to 0.66) (absolute benefit: 150 per 1000 with IV iron versus 319 per 1000). These analyses were assessed as having low certainty evidence.IV iron compared with oral iron may increase the number of participants who achieve target haemoglobin (13 studies, 2206 participants: RR 1.71, 95% CI 1.43 to 2.04) (absolute benefit: 542 participants per 1,000 with IV iron versus 317 per 1000 with oral iron), increased haemoglobin (31 studies, 3373 participants: MD 0.72 g/dL, 95% CI 0.39 to 1.05); ferritin (33 studies, 3389 participants: MD 224.84 microg/L, 95% CI 165.85 to 283.83) and transferrin saturation (27 studies, 3089 participants: MD 7.69%, 95% CI 5.10 to 10.28), and may reduce the dose required of erythropoietin-stimulating agents (ESAs) (11 studies, 522 participants: SMD -0.72, 95% CI -1.12 to -0.31) while making little or no difference to glomerular filtration rate (8 studies, 1052 participants: 0.83 mL/min, 95% CI -0.79 to 2.44). All analyses were assessed as having low certainty evidence. There were moderate to high degrees of heterogeneity in these analyses but in meta-regression, definite reasons for this could not be determined. AUTHORS' CONCLUSIONS The included studies provide low certainty evidence that IV iron compared with oral iron increases haemoglobin, ferritin and transferrin levels in CKD participants, increases the number of participants who achieve target haemoglobin and reduces ESA requirements. However, there is insufficient evidence to determine whether IV iron compared with oral iron influences death (all causes), cardiovascular death and quality of life though most studies reported only short periods of follow-up. Adverse effects were reported in only 50% of included studies. We therefore suggest that further studies that focus on patient-centred outcomes with longer follow-up periods are needed to determine if the use of IV iron is justified on the basis of reductions in ESA dose and cost, improvements in patient quality of life, and with few serious adverse effects.
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6.
De novo weekly and biweekly darbepoetin alfa dosing in pediatric patients with chronic kidney disease
Warady BA, Barcia J, Benador N, Jankauskiene A, Olson K, Podracka L, Shavkin A, Srivaths P, Wong CJ, Petersen J
Pediatric Nephrology (Berlin, Germany). 2017;33((1):):125-137
Abstract
BACKGROUND Darbepoetin alfa is a commonly prescribed erythropoiesis-stimulating agent (ESA) for correcting anemia in pediatric chronic kidney disease (CKD) patients. However, little information exists on its use in ESA-naive patients. This study evaluated the efficacy and safety of darbepoetin alfa in pediatric patients initiating ESA therapy. METHODS One-hundred sixteen pediatric ESA-naive subjects (aged 1-18 years) with CKD stages 3-5D and hemoglobin (Hb) <10 g/dl from 43 centers in the US, Europe, and Mexico were randomized by age (three groups) and dialysis status (yes vs. no) to receive darbepoetin alfa once weekly (QW) or every 2 weeks (Q2W) subcutaneously (not on dialysis and peritoneal dialysis subjects) and intravenously (hemodialysis subjects). The drug was titrated to achieve Hb levels of 10.0-12.0 g/dl over 25 weeks. Patient- and parent-reported health-related outcomes were measured by the Pediatric Quality of Life Inventory (PedsQL) in children ≥2 years. RESULTS In both groups, mean Hb concentrations increased to ≥11.0 g/dl over the first 3 months of treatment and remained stable within the 10.0-12.0 g/dl target range. The median time to achieve hemoglobin ≥10 g/dl was slightly longer for subjects <12 years (QW and Q2W, both 28 days) vs. those ≥12 years (23 and 22 days, respectively). Adverse event profiles were similar between groups, with QW, four (7%) and Q2W, five (9%). PedsQL scores showed modest increases. CONCLUSIONS Darbepoetin alfa can be safely administered either QW or Q2W to ESA-naive pediatric patients with CKD-related anemia to achieve Hb targets of 10.0-12.0 g/dl.
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Early erythropoietin reduced the need for red blood cell transfusion in childhood hemolytic uremic syndrome: a randomized prospective pilot trial
Pape L, Ahlenstiel T, Kreuzer M, Drube J, Froede K, Franke D, Ehrich JH, Haubitz M
Pediatric Nephrology (Berlin, Germany). 2009;24((5):):1061-4.
Abstract
Childhood hemolytic uremic syndrome (HUS) is most often caused by enterohemorrhagic Escherichia coli (EHEC). Due to severe hemolysis, red blood cell (RBC) transfusions are often necessary, and anemia is aggravated by low erythropoietin (EPO) levels caused by acute renal failure. In a single center, prospective study, we randomized ten children with EHEC-positive HUS into two therapeutic groups: one receiving EPO treatment (median age 2 years, age range 1-3 years) and the other receiving standard therapy (median age 2 years, age range 1-6 years). Red blood cell transfusions were performed when the hemoglobin level (Hb) fell below 5 mg/dl. The number of RBC transfusions was compared in both groups. The Hb level at admission was comparable between both groups (6. 4 vs. 8. 1 mg/dl, P > 0. 05, t-test). However, children in the EPO group required a significantly lower mean number of RBCs than those in the non-EPO group (0. 2 vs. 1. 4, P < 0. 04, t-test). Based on these results, we suggest that the early administration of EPO at the time of hemolytic anemia and beginning renal failure may attenuate renal anemia in children with EHEC-induced HUS and thereby reduce the number of RBC transfusions required. The results of this pilot study will have to be confirmed in a larger multicenter trial.
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8.
Randomized cross-over trial comparing albumin and frusemide infusions in nephrotic syndrome
Dharmaraj R, Hari P, Bagga A
Pediatric Nephrology (Berlin, Germany). 2009;24((4):):775-82.
Abstract
The contribution of hypoalbuminemia to impaired diuretic responsiveness can be overcome by administering larger doses of loop diuretics. However, the clinical efficacy of the combination of loop-acting diuretics with human albumin remains controversial. In the study reported here, 16 children with nephrotic syndrome and refractory edema were randomized in a cross-over trial to receive either the combination of 20% human albumin and frusemide infusion (HA+FU infusion group) or frusemide infusion alone (FU infusion group). At the end of study, median urine volume was 3. 27 [95% confidence interval (CI) 2. 04-4. 50] ml/kg per hour in the HA+FU infusion group and 1. 33 (95% CI 0. 79-1. 88) ml/kg per hour in the FU infusion group (P = 0. 01); the median daily sodium excretion was 58 (95% CI 30-366) mEq and 30 (95% CI 10-122) mEq (P = 0. 08), respectively The changes in other variables included weight loss [HA+FU 5. 2% (95% CI 3. 1-8. 8); FU 0. 8% (95% CI -1. 9 to 4. 1); P = 0. 006]; urine osmolality [HA+FU 315 (95% CI 220-426) mOsm/kg; FU 368 (95% CI 318-446) mOsm/kg; P = 0. 13]; osmolal clearance [HA+FU 1600 (95% CI 916-4140) ml/day; FU 880 (95% CI 510-2105) ml/day; P = 0. 01; free water clearance [HA+FU -190 (95% CI -960 to 280) ml/day; FU -162 (95% CI -446 to -70) ml/day; P = 0. 18]. The findings from this study suggest that the co-administration of albumin and frusemide infusions is more effective than the administration of frusemide infusion alone in inducing diuresis and natriuresis in patients with nephrotic syndrome.
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Population pharmacokinetic modeling of epoetin delta in pediatric patients with chronic kidney disease
Knebel W, Palmen M, Dowell JA, Gastonguay M
Journal of Clinical Pharmacology. 2008;48((7):):837-48.
Abstract
This analysis quantifies the population pharmacokinetics of subcutaneous and intravenous epoetin delta, an epoetin produced in a human cell line, in pediatric patients with chronic kidney disease and estimates the effects of covariate factors on epoetin delta and epoetin alfa pharmacokinetic parameters. Erythropoietin serum concentration data, taken from a phase III study conducted in 60 patients aged 1 to 17 years, were best described by a 1-compartment model with first-order absorption and elimination. The typical point estimates were clearance (0. 268 L/h), central volume of distribution (1. 03 L), absorption rate constant (0. 0554 h(-1)), and bioavailability (0. 708) for a 35-kg male < or = 10 years who was predialysis and on subcutaneous epoetin delta treatment. Erythropoietin pharmacokinetic parameters were similar in pediatric patients as compared with adults when scaled by weight. The subcutaneous administration of epoetin alfa exhibited lower systemic bioavailability than subcutaneous administration of epoetin delta.
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10.
Increased injection pain with darbepoetin-alpha compared to epoetin-beta in paediatric dialysis patients
Schmitt CP, Nau B, Brummer C, Rosenkranz J, Schaefer F
Nephrology, Dialysis, Transplantation. 2006;21((12):):3520-4.
Abstract
BACKGROUND Darbepoetin-alpha is applicable at longer injection intervals. Our early experience in children on peritoneal dialysis suggested increased injection pain compared to epoetin-beta, possibly due to technical differences or patient anxiety. METHODS To verify a possible difference in the painfulness of the injected fluids per se, we performed a prospective, randomized, double-blind trial in 13 paediatric end-stage renal disease patients. They received three injections of equivalent doses of darbepoetin-alpha or epoetin-beta in 0. 6 ml saline, using neutral syringes and 27G needles, at 4 week intervals. Pain perception was recorded immediately and after 30 min on a visual analogue scale (VAS, 0 = no pain, 10 = maximal pain; complemented by 5 faces for young children). RESULTS The patients perceived more intense immediate injection pain with darbepoetin-alpha than with epoetin-beta (5. 4 +/- 1 vs 2. 3 +/- 0. 6, P < 0. 05). This was confirmed by the impression of the parents (5. 3 +/- 1 vs 2. 0 +/- 0. 9, P < 0. 05) and the nurses (4. 4 +/- 1 vs 2. 2 +/- 0. 6, P < 0. 05). General injection pain was inversely related to patient age (R = -0. 77, P = 0. 001). Six patients perceived no or a mild difference in injection pain, whereas 7 subjects reported a markedly higher pain score (> or =4 VAS points) with darbepoetin-alpha. After 30 min, the injection site was largely painless with both drugs. No significant local reactions occurred with either medication (0. 3 +/- 0. 1 vs 0. 3 +/- 0. 1 on a 5-score scale). CONCLUSIONS Subcutaneous injections of darbepoetin-alpha are more painful than those of epoetin-beta in the majority of paediatric patients. The observed difference in painfulness is related to the nature of the injected compounds and may limit the subcutaneous applicability of darbepoetin-alpha in children.