Is There a Difference between the Allergic Potencies of the Iron Sucrose and Low Molecular Weight Iron Dextran?

BACKGROUND

The objectives of the present trial were to compare the side effects and safety of two intravenous iron preparations (iron-dextran, iron-sucrose) in patients with end stage renal disease.

METHODS

A total of 60 patients were randomized and assigned to one of two treatment groups (iron-dextran, n = 30; iron-sucrose, n = 30). A standard test dose of 25 mg of low molecular weight iron-dextran and iron-sucrose were administered over 15 minutes during the initial visit, monitoring very closely for adverse reactions. If this dose was well tolerated, 75 mg of iron diluted in 100 mL of normal saline was administered over 30 minutes. Adverse reactions were recorded.

RESULTS

The mean age of the patients was 51.5+/-17.4 years (range, 21 to 80 years). Of the 30 patients who received low molecular weight iron-dextran, 11 developed side effects (pruritus, 1 patient; wheezing, 1 patient; chest pain, 1 patient; nausea, 4 patients; hypotension, 1 patient; swelling, 1 patient; headache, 2 patients). Of the 30 patients who received iron-sucrose, 13 developed side effects (pruritus, 1 patient; wheezing, 1 patient; diarrhea, 1 patient; nausea, 4 patients; hypotension, 2 patients; swelling, 1 patient; headache, 3 patients). Adverse events occurred with similar frequency in the two treatment groups in our study (p > 0.05). We did not observe any serious reactions in the two groups.

CONCLUSION

We conclude that the incidence of side effects associated with iron-dextran was not different than that of iron-sucrose in our study. Large scale randomized studies are needed to compare the full side effect profile of intravenous iron preparations more precisely.

Efficacy and Safety of Intravenous Iron Therapy for HCV-Positive Haemodialysis Patients

BACKGROUND

Iron supplementation is the cornerstone of anaemia management in haemodialysis (HD) patients. However, efficacy and safety of intravenous (IV) iron therapy in hepatitis C virus (HCV)-positive HD patients is yet to be elucidated.

METHODS

Sixty-six maintenance HD patients with suboptimal response to recombinant human erythropoietin (rh-EPO) were administered IV iron. Each patient received 100 mg/session IV iron sucrose for ten consecutive HD sessions and then the dose was decreased to 50-100 mg weekly or biweekly. Patients were followed for haemoglobin (Hb), ferritin, rh-EPO dose requirements, transaminase levels, and adverse drug reactions.

RESULTS

Baseline demographic and clinical characteristics, as well as Hb, ferritin, transaminase levels, rh-EPO and iron doses were similar between HCV-positive (n = 32) and HCV-negative patients (n = 29). After 5 months of follow-up, a significant increase in ferritin and Hb levels and decrease in rh-EPO doses were observed in both groups. The incidence of adverse drug reactions was not associated with HCV serology. Significant elevation in both alanine and aspartate aminotransferase levels were detected in HCV-positive patients.

CONCLUSION

This study has shown that IV iron administration reverses suboptimal response to rh-EPO administration in HD patients regardless of HCV serology. There is however subtle increase of transaminase levels in HCV-positive patients. Further studies are warranted to reveal the impact of variation in serum transaminase levels during IV iron administration in HCV-positive HD patients.

Evaluation and treatment of iron deficiency in patients with kidney disease

Iron deficiency is common in patients with kidney disease and is one of the primary causes for decreased response to recombinant human erthropoietin (rHuEPO) therapy. Serum ferritin and percent tranferrin saturation are regarded as the preferred indirect measurements of iron status. The National Kidney Foundation-Kidney Disease Outcome Quality Initiative (K/DOQI) guidelines recommend levels of > 100 ng/ml and > 20%, respectively. These tests, however, have practical limitations and lack sensitivity and specificity to identify "functional" iron deficiency, which can occur in the presence of normal or even increased iron stores. Newer methods of assessing iron status are becoming available, with reticulocyte hemoglobin content (CHr) showing the most promise at this time. K/DOQ1 guidelines recommend that adequacy of iron should be based on the amount of iron needed to sufficiently achieve target hemoglobin and hematocrit levels of 11-12 g/dL, or 33-36%. Studies have demonstrated for a majority of hemodialysis and some predialysis and peritoneal dialysis patients that intravenous iron therapy is necessary to improve response, thus reducing the amount of rHuEPO needed to achieve these goals. Though intravenous iron is generally regarded as safe and effective, caution should be taken in regard to acceptable amounts of supplementation and long-term effects with the potential risk of iron overload.

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.