Strategies for iron supplementation: oral versus intravenous

Hepatocellular Damage Following Therapeutic Intravenous Iron Sucrose Infusion in a Child

The maximum tolerated single dose of intravenous iron infusion and iron pharmacokinetics are not known in children and not clear in adults. The case reported here is of a child given a large dose of intravenous iron sucrose (16 mg/kg) over 3 hours, who subsequently developed features of systemic iron toxicity. A TDM consultant discusses the case in the context of toxicokinetic analysis. Because the maximum tolerated dose and pharmacokinetics of intravenous iron preparations are not known, their use in both adults and children should still be undertaken with caution.

Dietary iron affects inflammatory status in a rat model of colitis

Iron deficiency anemia is a common feature in inflammatory bowel disease, and oral supplementation is one of the mainstay therapies. However, there is some concern that oral iron supplementation may lead to oxidative stress and exacerbation of inflammation. Our objective was to study the effect of severely deficient, moderately deficient, normal and high iron status on oxidative stress and the course of inflammation in a rat model of colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS). The rats were randomly assigned to receive the low-iron diet for 3 (moderately iron-deficient group, n = 16) or 5 (severely iron-deficient group, n = 16) wk, the normal iron diet for 2 wk (normal iron group, n = 16) or the high-iron diet for 2 wk (high-iron group, n = 16). Malondialdehyde concentration, electroparamagnetic resonance measurement, myeloperoxidase activity, and histological analysis were used to evaluate oxidative stress. Noncolitic rats in the high-iron group had higher oxidative stress parameters than those in the other groups. The induction of colitis resulted in severe inflammatory changes in the high-iron and severely iron-deficient groups, and produced higher histological scores in the colon of the normal and high-iron groups. Iron overload, oxidative stress, and inflammation were lower in the moderately iron-deficient group compared with the other 3 groups. In conclusion, we suggest that low rather than normal or high iron supplementation should be considered for the treatment of iron deficiency in inflammatory bowel disease.

Management of anemia in patients with cancer

Anemia is extremely common in patients with cancer. Low hemoglobin levels are associated with diminished quality of life and possibly decreased overall survival. Successful treatment of anemia has undeniable benefits for patients, often yielding dramatic symptomatic improvement that can be very satisfying for clinicians to observe. This review focuses on evolving issues in the management of anemia in patients suffering from cancer. Topics addressed include new evidence-based guidelines concerning the use of epoetin alfa, the evolving role of darbepoetin alfa in cancer-associated anemia, the potential for concomitant iron supplementation to maximize response to erythropoietic agents, the unresolved question of whether erythropoietin use affects survival in cancer patients, new concerns about the risk of thromboembolism in cancer patients with higher hemoglobin levels who are receiving epoetin, and possible immunosuppressive effects of blood product transfusions that may have relevance to neoplasia progression.

Postoperative intravenous iron used alone or in combination with low-dose erythropoietin is not effective for correction of anemia after cardiac surgery

OBJECTIVES

The aim of this study was to examine whether intravenous iron III-hydroxide sucrose complex (IHSC) used alone was sufficient to provide rapid correction of anemia after cardiac surgery and whether additional stimulation of erythropoiesis is possible by means of a single low dose of recombinant-human erythropoietin (r-HuEPO) administration.

DESIGN

Prospective, randomized, double-blind study.

SETTING

The study was conducted in a university hospital.

PARTICIPANTS

One hundred twenty American Society of Anesthesiologists II or III patients, who underwent elective cardiac surgery using cardiopulmonary bypass and in whom postpump hemoglobin ranged between 7 and 10 g/dL.

INTERVENTIONS

Patients were divided into 3 groups: group I = control; group II received postoperative intravenous iron supplementation with an iron III-hydroxide sucrose complex (IHSC); and group III received IV iron and a single dose of r-HuEPO (300 U/kg).

MEASUREMENTS AND RESULTS

No significant difference in transfusion needs was observed among the 3 groups (22%, 25%, and 17% of patients transfused in groups I, II, and III, respectively). Hemoglobin levels, reticulocyte counts, and serum ferritin levels were evaluated at different time intervals (until day 30 postoperatively). No side effects because of iron administration were noted in the study. Reticulocyte counts increased rapidly at day 5 (2.24% +/- 1.11%, 1.99% +/- 1.44%, and 3.84% +/- 2.02% in groups I, II, and III, respectively) and decreased after day 15 in the 3 groups. Ferritin levels increased significantly at day 5 in the 2 treated groups (899.33 +/- 321.55 ng/mL in group II, 845.75 +/- 289.96 ng/mL in group III v 463.15 +/- 227.74 ng/mL in group I). In group I, ferritin levels, after a slight elevation on day 5, decreased at day 15 to lower than baseline levels. No significant difference in hemoglobin increase was noted among the 3 groups.

CONCLUSION

Postoperative intravenous iron supplementation alone or in combination with a single dose of r-HuEPO (300 U/kg) is not effective in correcting anemia after cardiac surgery.

On the relative safety of parenteral iron formulations

BACKGROUND

Intravenous iron is usually required to optimize the correction of anaemia in persons with advanced chronic kidney disease and end-stage renal disease. Randomized clinical trials may have insufficient power to detect differences in the safety profiles of specific formulations.

METHODS

We obtained data from the US Food and Drug Administration on reported adverse drug events (ADEs) related to the provision of three formulations of intravenous iron during 1998-2000. We estimated the relative risks [odds ratios (OR)] of ADEs associated with the use of higher molecular weight iron dextran and sodium ferric gluconate complex compared with lower molecular weight iron dextran using 2 x 2 tables.

RESULTS

The total number of reported parenteral iron-related ADEs was 1981 among approximately 21,060,000 doses administered, yielding a rate of 9.4 x 10(-5), or approximately 94 per million. Total major ADEs were significantly increased among recipients of higher molecular weight iron dextran (OR 5.5, 95% CI 4.9-6.0) and sodium ferric gluconate complex (OR 6.2, 95% CI 5.4-7.2) compared with recipients of lower molecular weight iron dextran. We observed significantly higher rates of life-threatening ADEs, including death, anaphylactoid reaction, cardiac arrest and respiratory depression among users of higher molecular weight compared with lower molecular weight iron dextran. There was insufficient power to detect differences in life-threatening ADEs when comparing lower molecular weight iron dextran with sodium ferric gluconate complex.

CONCLUSIONS

Parenteral iron-related ADEs are rare. Using observational data, overall and most specific ADE rates were significantly higher among recipients of higher molecular weight iron dextran and sodium ferric gluconate complex than among recipients of lower molecular weight iron dextran. These data may help to guide clinical practice, as head-to-head clinical trials comparing different formulations of intravenous iron have not been conducted.

The effects of iron dextran on the oxidative stress in cardiovascular tissues of rats with chronic renal failure

BACKGROUND

Redox-active iron can promote oxidative stress and tissue injury by catalyzing hydroxyl radical generation and lipid peroxidation. Intravenous iron preparations are routinely administered in conjunction with erythropoietin to treat anemia in patients with chronic renal failure (CRF), a condition that is marked by oxidative stress and inflammation. This treatment frequently elevates iron burden, which can potentially intensify oxidative stress and, thus, cardiovascular disease in this population.

METHODS

We studied renal function and oxidative stress parameters in the cardiovascular tissues of CRF (5/6 nephrectomized) and sham-operated control rats 3 months after a single intravenous infusion of iron dextran (500 mg/kg).

RESULTS

Arterial pressure was equally elevated and creatinine clearance was equally reduced in both iron-treated and -untreated CRF groups. Iron administration significantly raised the blood hemoglobin, serum iron concentration, and transferrin saturation in both CRF and control groups. Iron administration resulted in a significant rise in plasma concentration of lipid peroxidation product, malondialdehyde in the CRF rats, and an insignificant rise in the control group. Plasma oxidized low-density lipoprotein (LDL) concentration was increased in the CRF groups, and was not affected by iron administrations. Iron administration raised nitrotyrosine abundance in the aorta of CRF but not in the control group. Left ventricular tissue abundance of p22(phox) subunit of NAD(P)H oxidase was elevated in CRF group and was not affected, whereas p67(phox) subunit abundance was raised by prior iron administration. Iron administration insignificantly lowered aorta p22(phox), but had no effect on p67(phox) subunit abundance in the treated CRF group. Previous iron administration significantly lowered superoxide dismutase and catalase abundance in the aorta and glutathione peroxidase in the left ventricle of CRF animals, but did not significantly change these parameters in the iron-treated control animals.

CONCLUSION

A single intravenous injection of iron dextran increased oxidative stress in the cardiovascular tissues in the CRF group, but not the control rats, pointing to heightened susceptibility to iron-mediated toxicity in CRF. However, administration of iron dextran did not adversely affect kidney function, and favorably affected hemoglobin concentration in rats with CRF induced by renal mass reduction. Further studies are needed to explore the effects of other parenteral iron preparations, repeated intravenous iron administration, and presence of comorbid conditions such as diabetes.

Intermittent versus maintenance iron therapy in children on hemodialysis: a randomized study

In patients with renal anemia, iron therapy can be administered intermittently or regularly at a low dose. We performed a randomized clinical trial in pediatric patients with end-stage renal failure on hemodialysis and absolute or functional iron deficiency. The study group received maintenance iron therapy according to the ferritin serum levels and the control group received intermittent 10-weekly doses. Success was defined as stabilization of ferritin levels between 100 and 800 microg/l and transferrin saturation (TSAT) between 20% and 50%, in addition to an increase in the hemoglobin level. The major reason for exclusion was iron overload. The study group received 6 mg/kg per month of parenteral iron [95% confidence interval (CI) 3.3-8.8] and the control group 14.4 mg/kg per month (95% CI 12-16.8) ( P<0.001). After 4 months of treatment, ferritin levels increased to 66 microg/l (95% CI 69-200) in the study group and to 334 microg/l (95% CI 145-522) in the control group ( P=0.009). Maintenance therapy and intermittent weekly doses were successful in 73% and 38%, respectively. After 3 months of treatment, hemoglobin levels increased to 10 g/dl, with no difference between the groups. However, in the control group the increase in hemoglobin levels was unsustained, and 3 patients needed transfusion. Patients in the control group had a higher risk of iron overload than patients in the study group (70% vs. 19%). Thus, the regimen based on assessment of serum ferritin levels was more efficient than the intermittent regimen because it increased and maintained the hemoglobin levels with lower iron doses and a lower risk of iron overload.

Effect of iron sucrose on human peritoneal mesothelial cells

BACKGROUND

Iron supplementation is often required in uraemic patients with anaemia. Peritoneal cavity was proposed as an alternative intravenous route for iron infusion in patients treated with peritoneal dialysis. We studied the effect of iron sucrose (Venofer) on the function of human peritoneal mesothelial cells maintained in in vitro culture.

MATERIALS AND METHODS

In in vitro experiments on human peritoneal, the mesothelial effect of elemental iron (in conc. 0.0001-1 mg mL-1) present in Venofer on their viability, growth and synthesis of IL-6 was studied. Additionally we evaluated with a fluorescent probe (2',7'-dichlorodihydro-fluorescein diacatate) generation of reactive oxygen species in cells exposed to iron sucrose. We also measured accumulation of iron in the cytoplasm of mesothelial cells after their in vitro exposure to Venofer.

RESULTS

In in vitro conditions iron induces a dose-dependent inhibition of viability of the mesothelial cells as reflected by inhibition of the cells growth by 34% at Fe 0.1 mg mL-1 vs. control (P < 0.05) increased release of lactate dehydrogenase (LDH) from the cytosol: 67.1 +/- 30.3 mU mL-1 at Fe 1 mg mL-1 vs. 7.9 +/- 6.4 in control group (P < 0.001), and reduced synthesis of IL-6: 209 +/- 378 pg mg-1 cell protein at Fe 1 mg mL-1 vs. 38674 +/- 4146 pg mg-1 cell protein in controls (P < 0.001). Cytotoxicity of iron towards mesothelial cells was enhanced in vitro when it was tested in presence of the dialysis fluid. Iron used in vitro at concentration 0.0001 mg mL-1 and greater induces generation of oxygen-derived free radicals in mesothelial cells. Furthermore, iron is taken by these cells and stored in their cytosol, resulting in stimulation of the intracellular generation of free radicals.

CONCLUSIONS

We conclude that iron used in the form of iron sucrose is cytotoxic to human peritoneal mesothelial cells. Accumulation of iron sucrose within cytoplasm of these cells may lead to induction of its chronic cytotoxic effect.

Ferrous fumarate deteriorated plasma antioxidant status in patients with Crohn disease

BACKGROUND

Iron deficiency anaemia is a frequent complication of Crohn disease. Treatment with ferrous iron (Fe2-) compounds is often unsatisfactory and is associated with gastrointestinal side effects. Theoretically, oral iron supplementation may even be harmful, because iron may reinforce intestinal inflammation by catalysing production of reactive oxygen species. We investigated the effect of ferrous iron on disease activity and plasma antioxidant status in patients with active Crohn disease.

METHODS

Ten patients with Crohn disease and iron deficiency and 10 healthy controls were given ferrous fumarate 120 mg for 7 days. The Crohn Disease Activity Index, gastrointestinal complaints and blood samples for antioxidant status, anaemia, inflammation and iron absorption were investigated on day 1 and day 8.

RESULTS

During 1 week of ferrous fumarate supplementation, the Crohn Disease Activity Index tended to increase (P = 0.071). Patients experienced aggravation of diarrhoea, abdominal pain and nausea. Plasma-reduced cysteine was lower (P = 0.038) in patients than it was in controls. One week of ferrous iron supplementation further decreased reduced cysteine (P < 0.001) and significantly decreased plasma-reduced glutathione (P = 0.004) in the patients. Serum iron increased significantly in patients after an oral iron load test (from 5.8 +/- 3.2 micromol/L to 30.9 +/- 13.1 micromol/L).

CONCLUSIONS

Treatment of iron deficiency with ferrous fumarate deteriorated plasma antioxidant status and increased specific clinical symptoms in patients with active Crohn disease. Plasma reduced cysteine may be a sensitive indicator for oxidative stress in the intestine.

Pharmacokinetic-pharmacodynamic modelling of recombinant human erythropoietin in athletes : a population approach

OBJECTIVE

To develop a pharmacokinetic model able to take into account the negative feedback loop of endogenous erythropoietin production observed after repeated administration of recombinant human erythropoietin (rHuEPO), and to propose a pharmacokinetic-pharmacodynamic model capable of assessing and quantifying the relationship between changes in: (i) serum soluble transferrin receptor (sTfR) levels, (ii) reticulocyte haematocrit (RetHct), and (iii) percentage macrocytes (%Macro) secondary to repeated administration of rHuEPO.

SUBJECTS AND METHODS

Eighteen trained athletes (three females and 15 males) participated in this study. They received subcutaneous injections of rHuEPO-α 50 U/kg bodyweight for 26 days (days 1, 3, 5, 9, 10, 12, 15, 17, 19, 22, 24 and 26) with iron supplementation. Venous blood samples were collected before, during and after rHuEPO treatment for determination of serum erythropoietin concentrations, haematological parameters (RetHct, %Macro) and sTfR levels. Population pharmacokinetic-pharmacodynamic calculations were performed using NONMEM® software.

RESULTS

The serum erythropoietin concentration-time profile was compatible with a one-compartment open model and first-order input rate. The mean half-lives calculated from the first and the terminal log-linear parts of the curves were 5.2 and 35.8 hours, respectively. After subcutaneous administration of rHuEPO, the terminal part of the curve should correspond to the absorption rather than the elimination phase ('flip-flop' phenomenon). The total clearance divided by bio-availability was 4.33 L/h. The pharmacodynamic relationship based on a sigmoid E(max) model can be reasonably used to relate changes observed in haematological and biochemical markers after rHuEPO administration to changes in serum erythropoietin concentrations. rHuEPO induces a delayed increase in sTfR levels, RetHct and %Macro. The half-life (t1/2) k(0) (equilibration delay) values were 10.2 days for sTfR, 2 days for RetHct and 10.2 days for %Macro. The pharmaco-kinetic-pharmacodynamic approach developed in this study allowed below-base-line decreases in RetHct levels (i.e. from days 10-26 after the end of rHuEPO treatment) to be taken into account. A negative-feedback loop of red blood cell production further to high haemoglobin and haematocrit values could explain this decrease.

CONCLUSIONS

The approach described here may provide an additional tool in the war against drug abuse by athletes; indeed, the model could be useful for simulating pharmacokinetic-pharmacodynamic relationships according to different rHuEPO dosage schedules.

Pharmacologic and cytokine treatment of commonly encountered anemias

Anemia has multiple etiologies: it may be caused by nutritional deficiencies or congenital abnormalities, or it may be associated with a number of conditions, such as chronic kidney disease, cancer, or human immunodeficiency virus (HIV) infection. Anemia is associated with an increase in morbidity and mortality in patients with endstage renal disease, cancer, or HIV infection. Each case of anemia is different, with different causes, clinical consequences, and treatment strategies. Identifying the most appropriate treatment requires an understanding of the etiology of the anemia and investigation of the nature of the causative medical condition. In some cases, such as anemia associated with chronic kidney disease, treatment is well defined and consists of administration of erythropoiesis-stimulating agents, accompanied by iron supplementation where appropriate. In other instances, such as megaloblastic anemia, which may be caused by vitamin or folate deficiency, vitamin supplementation alone may be a clinically appropriate treatment. This article gives an overview of the etiologies and current therapies of the most commonly encountered types of anemia, highlighting both the diverse nature of the condition, and the equally diverse pharmacologic and supportive treatment approaches.

Pathogenesis and treatment of anaemia of chronic disease

Anaemia of chronic disease (ACD), the most frequent anaemia among hospitalized patients, develops under chronic inflammatory disorders such as chronic infections, cancer or autoimmune diseases. A number of different pathways contribute to ACD, such as diversion of iron traffic, a diminished erythropoiesis, a blunted response to erythropoietin, erythrophagocytosis and bone marrow invasion by tumour cells and pathogens. Nevertheless, ACD is a reflection of an activated immune system and possibly results from an innovative defence strategy of the body in order to withdraw the essential growth factor iron from invading pathogens and to increase the efficacy of cell-mediated immunity. Diagnosis of ACD can be assessed by examination of chances in serum iron parameters with low to normal serum iron, transferrin saturation and transferrin concentrations on the one hand and normal to increased ferritin, zinc protoporphyrin IX and cytokine levels on the other side. Therapy of ACD includes the cure of the underlying the disease. Apart from this transfusions for rapid correction of haemoglobin levels, and human recombinant erythropoietin for prolonged therapy are used. However, response rates to recombinant erythropoietin are sometimes low. Iron alone should be strictly avoided due to its growth-promoting effect towards micro-organisms and tumour cells and because of it capacity to inhibit T-cell-mediated immune effector pathways. We urgently need prospective clinical trials to gain knowledge about the effects of anaemia correction and/or the use of erythropoietin towards the course of the underlying disease, to find out if a combination therapy with erythropoietin and iron may be beneficial in ACD and to define therapeutic end-points.

Total dose intravenous infusion of iron dextran for iron-deficiency anemia in children with inflammatory bowel disease

BACKGROUND

Iron-deficiency anemia is a frequent complication in children with inflammatory bowel disease (IBD). Parenteral iron therapy is rarely prescribed because of concern about potential side effects. The aim of this study was to retrospectively evaluate the safety and efficacy of total dose intravenous (TDI) iron therapy.

METHODS

Charts of all the pediatric patients with IBD who received TDI iron therapy between February of 1994 and February of 2000 were reviewed.

RESULTS

Seventy patients (20 with ulcerative colitis and 50 with Crohn disease) received a total of 119 TDI iron dextran infusions. Thirty-four patients qualified for the efficacy analysis. The average increase in hemoglobin concentration was 2.9 g/dL, (P < 0.0001). Eleven immediate hypersensitivity reactions developed in 10 patients (9% of the total number of infusions). None of the reactions was life threatening and none required hospitalization.

CONCLUSIONS

Total dose intravenous infusion of iron dextran, when appropriately used, is a safe and potentially efficacious treatment for children with inflammatory bowel disease and iron deficiency anemia who are unresponsive to or noncompliant with oral iron therapy.

Evaluation of intestinal iron absorption by indirect methods in patients on hemodialysis receiving oral iron and recombinant human erythropoietin

Intestinal iron absorption was evaluated in 40 patients on hemodialysis therapy treated over 4 months with 105 mg/d of oral iron and recombinant human erythropoietin (rHuEPO). The effect of iron stores, erythropoietic activity (EA), and route of rHuEPO administration on absorption was evaluated. Iron was administered after basal determinations had been made and was stopped 15 days before obtaining the final determinations. Intestinal iron absorption was calculated by summing the increase in hemoglobin (Hb) iron (iron used for the synthesis of new Hb) and variations in estimated tissue iron reserves (reserves at the end of the study minus basal reserves). Markers of EA included soluble transferrin receptors (sTfRs) and erythron transferrin uptake (ETU). Iron losses caused by dialysis or normal obligatory iron losses were not measured. Hb levels increased from 8.38 +/- 1.4 to 10.75 +/- 1.5 g/dL (P < 0.05). sTfR levels reached their maximum value at 45 days (3.22 +/- 0.84 mg/mL; P < 0.05), and ETU increased from 40 +/- 26 to 61 +/- 39 micromol/L whole blood/d (P = 0.007). Intestinal iron absorption was 238 mg (interquartile range [Q75 to Q25], 255) at 2 months and 348 mg (Q75 to Q25, 475) at 4 months (P =0.02) and correlated positively with hematocrit at the end of the study (r = 0.826; P = 0.0001). No relationship between iron absorption and basal serum ferritin level or EA markers was observed. Intestinal iron absorption was similar regardless of the route of rHuEPO administration. In conclusion, intestinal iron absorption from medicinal iron covers erythropoietic requirements and allows Hb levels to increase significantly. It is proportional to the degree of efficient erythropoiesis reached and independent of tissue iron stores present before treatment, markers of EA, and rHuEPO administration route.

Darbepoetin Alfa

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Intravenous iron sucrose: establishing a safe dose

It is now recognized that the majority of patients on epoetin therapy require intravenous (IV) iron supplementation to maximize the response to treatment. Of the IV iron preparations available, iron sucrose has proved its efficacy and safety; however, there are no guidelines or systematic studies examining the optimum safe dosage regimen for this compound. The aim of the present study was to investigate prospectively a variety of dosing regimens for IV iron sucrose in patients with renal failure to develop treatment strategies for this preparation. A total of 335 iron infusions was administered to 249 patients in this study, which was conducted in four phases. In phase I, 89 patients were administered a dose of 200 mg as an IV infusion over 2 hours. No adverse events were seen. A 500-mg dose by 2-hour infusion was then assessed, but was abandoned after 8 of 22 patients developed reactions characterized by dizziness, hypotension, and nausea. The dose was then reduced to 300 mg by 2-hour infusion for the next 189 patients, and again, no adverse reactions were witnessed. Finally, a 400-mg dose by 2-hour infusion was examined in 35 patients, but 2 patients experienced such symptoms as hypotension, nausea, and lower back pain. Both the 200- and 300-mg doses of IV iron sucrose administered over 2 hours appear to be safe. The incidence of adverse events with the 400- and 500-mg doses administered as a 2-hour infusion seems too high to recommend their routine use, although it may be possible to administer these doses over a longer period.

A prospective crossover trial comparing intermittent intravenous and continuous oral iron supplements in peritoneal dialysis patients

BACKGROUND

Concomitant iron supplementation is required in the great majority of erythropoietin (Epo)-treated patients with end-stage renal failure. Intravenous (i.v.) iron supplementation has been demonstrated to be superior to oral iron therapy in Epo-treated haemodialysis patients, but comparative data in iron-replete peritoneal dialysis (PD) patients are lacking.

METHODS

A 12-month, prospective, crossover trial comparing oral and i.v. iron supplementation was conducted in all Princess Alexandra Hospital PD patients who were on a stable dose of Epo, had no identifiable cause of impaired haemopoiesis other than uraemia, and had normal iron stores (transferrin saturation >20% and serum ferritin 100-500 mg/l). Patients received daily oral iron supplements (210 mg elemental iron per day) for 4 months followed by intermittent, outpatient i.v. iron infusions (200 mg every 2 months) for 4 months, followed by a further 4 months of oral iron. Haemoglobin levels and body iron stores were measured monthly.

RESULTS

Twenty-eight individuals were entered into the study and 16 patients completed 12 months of follow-up. Using repeated-measures analysis of variance, haemoglobin concentrations increased significantly during the i.v. phase (108+/-3 to 114+/-3 g/l) compared with each of the oral phases (109+/-3 to 108+/-3 g/l and 114+/-3 to 107+/-4 g/l, P<0.05). Similar patterns were seen for both percentage transferrin saturation (23.8+/-2.3 to 30.8+/-3.0%, 24.8+/-2.1 to 23.8+/-2.3%, and 30.8+/-3.0 to 26.8+/-2.1%, respectively, P<0.05) and ferritin (385+/-47 to 544+/-103 mg/l, 317+/-46 to 385+/-47 mg/l, 544+/-103 to 463+/-50 mg/l, respectively, P=0.10). No significant changes in Epo dosages were observed throughout the study. I.v. iron supplementation was associated with a much lower incidence of gastrointestinal disturbances (11 vs 46%, P<0.05), but exceeded the cost of oral iron treatment by 6.5-fold.

CONCLUSIONS

Two-monthly i.v. iron infusions represent a practical alternative to oral iron and can be safely administered to PD patients in an outpatient setting. Compared with daily oral therapy, 2-monthly i.v. iron supplementation in PD patients was better tolerated and resulted in superior haemoglobin levels and body iron stores.

Role of oral versus IV iron supplementation in the erythropoietic response to rHuEPO: a randomized, placebo-controlled trial

BACKGROUND

Preoperative treatment with rHuEPO (epoetin alfa: EPREX, Janssen-Cilag; or PROCRIT, Ortho Biotech) in conjunction with iron supplementation increases the erythropoietic response in elective orthopedic surgery patients, but it is not known whether the magnitude of this response is dependent on the route of iron administration.

STUDY DESIGN AND METHODS

Non-iron-deficient patients undergoing elective orthopedic surgery (N = 110) with baseline Hb > or =10 to < or =13 g per dL were randomly assigned to receive either epoetin alfa (600 IU/kg) plus IV iron (n = 29) or oral iron (n = 29) or placebo plus IV iron (n = 25) or oral iron (n = 27) in this 14-day study. RBC production, Hb, Hct, reticulocytes, iron status, and adverse events were monitored throughout the study.

RESULTS

Epoetin alfa treatment plus either oral or IV iron supplementation significantly increased total RBC production, Hb, Hct, and reticulocytes over the values seen with the respective placebo treatments (p = 0.0001). There were no differences between the epoetin alfa treatment groups. Placebo treatment plus oral or IV iron supplementation was not associated with increases in hematologic values. There were no differences in the incidence of adverse events among the treatment groups.

CONCLUSION

There was a comparable erythropoietic response to epoetin alfa, irrespective of the route of iron administration. The route of iron administration, therefore, does not modulate the erythropoietic response to epoetin alfa in patients who are not iron deficient. Safety and convenience benefits may be gained by adopting oral iron supplementation in this patient subset.

Suspected iron dextran-related adverse drug events in hemodialysis patients

Despite the use of recombinant erythropoietin, anemia remains a significant problem for patients with end-stage renal disease, in part related to chronic dialysis-related blood loss and resultant iron deficiency. Because oral iron preparations have been relatively ineffective and poorly tolerated in this population, intravenous (IV) iron dextran has been widely prescribed, despite a finite risk for adverse effects associated with its use. We analyzed data from Fresenius Medical Care North America (FMCNA) clinical variance reports to determine the incidence of suspected iron dextran-related adverse drug events (ADEs) and associated patient characteristics, dialysis practice patterns, and outcomes. We used a case-cohort study design, comparing individuals who experienced suspected ADEs with the overall FMCNA population. Among 841,252 IV iron dextran administrations from October 1998 through March 1999, there were 165 reported suspected ADEs, corresponding to an overall rate of 0.000196%, or approximately 20 per 100,000 doses. Forty-three patients (26%) required an independent emergency department evaluation, 18 patients (11%) required hospitalization, and 1 patient (0.6%) died. Dyspnea (43%), hypotension (23%), and neurological symptoms (23%) were the most common major ADEs; nausea (34%), vomiting (23%), flushing (27%), and pruritus (25%) were the most common other ADEs. ADEs were 8.1-fold more common among patients administered Dexferrum (American Regent Laboratories, Inc, Shirley, NY) compared with those administered InFed (Watson Pharmaceuticals, Phoenix, AZ). In summary, serious adverse reactions to IV iron dextran are rare in clinical practice. The risk appears to depend on the specific formulation of IV iron dextran. Otherwise, iron dextran-related ADEs are difficult to predict.

Unanticipated favorable effects of correcting iron deficiency in chronic hemodialysis patients

BACKGROUND

Correction of anemia in hemodialysis patients is seldom completely attained, and the response of parameters other than hemoglobin concentration to anemia correction has not been evaluated in detail.

METHODS

Laboratory parameters that suggest iron deficiency occurred in 10-15% of 206 recombinant human erythropoietin (rhEPO)-treated patients. Oral iron was given for 9 months and intravenous iron thereafter on a patient-specific basis when iron deficiency was evident. Eighty-seven hemodialysis patients with data for 12 months were followed for another 12 months. A computerized information system enabled data management and analysis.

RESULTS

With oral iron, serum ferritin decreased (P < 0.001), indicating further iron depletion. With intravenous iron, hemoglobin increased, evidence of iron deficiency decreased, and less rhEPO was needed. Striking macrocytosis appeared. Serum albumin and serum creatinine/kg body weight (an index of muscle mass) increased, while blood pressure decreased. Data were reanalyzed in four mean corpuscular volume (MCV) quartiles and two ferritin subsets at study onset. Iron deficient erythropoiesis (low MCV, mean corpuscular hemoglobin [MCH], and transferrin saturation) was striking in quartile 1; low ferritin was prevalent in all quartiles. With intravenous iron, hemoglobin increased only in quartile 1, the quartile with the greatest decrease (52%) in rhEPO dose. MCV increased in all quartiles (P < 0.001). Serum albumin increased in all MCV quartiles and both ferritin subsets, but significant creatinine/kg increase and blood pressure decrease occurred only in the low-ferritin subset.

CONCLUSIONS

Macrocytosis occurred with intravenous iron replacement. The universal MCV increase suggests unrecognized, inadequately treated, folic acid deficiency unmasked by an adequate iron supply. There was also improved well being. Effects were most clearly evident in patients with deficient iron stores.

Catalytically active iron and bacterial growth in serum of haemodialysis patients after i.v. iron-saccharate administration

BACKGROUND

I.v. iron is commonly administered to haemodialysis patients suffering from anaemia to improve their response to erythropoietin therapy. It has been unclear whether routinely used doses of i.v. iron preparations could result in iron release into plasma in amounts exceeding the iron binding capacity of transferrin. Here, we have studied the effect of 100 mg of iron saccharate given as an i.v. injection on transferrin saturation and the appearance of potentially harmful catalytically active iron.

METHODS

We followed serum iron, transferrin and transferrin-saturation before and 5-210 min after administration of iron saccharate in 12 patients on chronic haemodialysis due to end-stage renal disease. We measured catalytically active iron by the bleomycin-detectable iron (BDI) assay and transferrin iron forms by urea gel electrophoresis, and studied iron-dependent growth of Staphylococcus epidermidis inoculated into the serum samples in vitro.

RESULTS

The iron saccharate injection resulted in full transferrin saturation and appearance of BDI in the serum in seven out of the 12 patients. BDI appeared more often in patients with a low serum transferrin concentration, but it was not possible to identify patients at risk based on serum transferrin or ferritin level before i.v. iron. The average transferrin saturation and BDI level increased until the end of the follow-up time of 3.5 h. The appearance of BDI resulted in loss of the ability of patient serum to resist the growth of S. epidermidis, which was restored by adding iron-free apotransferrin to the serum. Iron saccharate, added to serum in vitro, released only little iron and promoted only slow bacterial growth, but caused falsely high transferrin saturation by one routinely used serum iron assay.

CONCLUSIONS

The results indicate that 100 mg of iron saccharate often leads to transferrin oversaturation and the presence of catalytically active iron within 3.5 h after i.v. injection. As catalytically active iron is potentially toxic and may promote bacterial growth, it may be recommendable to use dosage regimens for i.v. iron that would not cause transferrin oversaturation.

Anemia in IBD: the overlooked villain

During the past decade relevant progress has been made in the understanding and treatment of IBD-associated anemia. Effective replacement of iron deficits has become safe by using novel intravenous iron preparations such as iron sucrose. The ability of erythropoietin to interfere with key mechanisms of myelosuppression in anemia of chronic diseases also benefits patients with IBD-associated anemia. Concerns about cost effectiveness have been raised and weighed against the potential improvement in quality of life. Gastroenterologists who are caring for IBD patients should be concerned with low hemoglobin levels, since the quality of life in these patients can be as low as in anemic patients with advanced cancer. Also provided is a structured approach to cost-effective therapy.

Anemia in IBD: the overlooked villain

During the past decade relevant progress has been made in the understanding and treatment of IBD-associated anemia. Effective replacement of iron deficits has become safe by using novel intravenous iron preparations such as iron sucrose. The ability of erythropoietin to interfere with key mechanisms of myelosuppression in anemia of chronic diseases also benefits patients with IBD-associated anemia. Concerns about cost effectiveness have been raised and weighed against the potential improvement in quality of life. Gastroenterologists who are caring for IBD patients should be concerned with low hemoglobin levels, since the quality of life in these patients can be as low as in anemic patients with advanced cancer. Also provided is a structured approach to cost-effective therapy.

Total dose iron infusion: safety and efficacy in predialysis patients

Iron deficiency anemia is not uncommon in predialysis patients. Oral iron often cannot maintain adequate iron stores. Hence we evaluated the safety and efficacy of total dose infusion (TDI) of iron in these patients. Anemic predialysis patients were screened and those with Hb < 7.0 g/dL and serum ferritin < 200 ng/mL were selected. Patients with active bleeding and acute liver disease were excluded. All patients were on oral iron 100 mg/day. None of the patients were on erythropoeitin. 11 patients (6 males and 5 females), aged 45.9 +/- 15 yrs, were suitable. Hb was 5.9 +/- 1.0 g/dL and serum ferritin was 89.5 + 50 ng/mL. The preparation used was iron dextran. A test dose of 25 mg in 100 mL normal saline was administered over 1 hr to all patients. One patient had fever and chills during the test dose and was not given TDI. 10 patients received TDI. None of these patients had any problem during the infusion. The dose of iron administered was 900 + 316.2 mg. One patient who received 1600 mg had arthralgia-myalgia and another patient had thrombophlebitis following TDI. One month after TDI, Hb was 8.0 + 1.0 g/dL and serum ferritin was 362 ng/mL. We feel that TDI is a safe and effective method of correcting iron deficiency in predialysis patients.