A case of osteomalacia due to deranged mineral balance caused by saccharated ferric oxide and short-bowel syndrome: A case report

RATIONALE

Saccharated ferric oxide has been shown to lead to elevation of fibroblast growth factor 23, hypophosphatemia, and, consequently, osteomalacia. Moreover, mineral imbalance is often observed in patients with short-bowel syndrome to some degree.

PATIENT CONCERNS

A 62-year-old woman with short-bowel syndrome related with multiple resections of small intestines due to Crohn disease received regular intravenous administration of saccharated ferric oxide. Over the course of treatment, she was diagnosed with tetany, which was attributed to hypocalcemia. Additional assessments of the patient revealed not only hypocalcemia, but also hypophosphatemia, hypomagnesemia, osteomalacia, and a high concentration of fibroblast growth factor 23 (314 pg/mL).

DIAGNOSES

We diagnosed her with mineral imbalance-induced osteomalacia due to saccharated ferric oxide and short-bowel syndrome.

INTERVENTIONS

Magnesium replacement therapy and discontinuation of saccharated ferric oxide alone.

OUTCOMES

These treatments were able to normalize her serum mineral levels and increase her bone mineral density.

LESSONS

This case suggests that adequate evaluation of serum minerals, including phosphate and magnesium, during saccharated ferric oxide administration may be necessary, especially in patients with short-bowel syndrome.

A randomized trial of iron isomaltoside versus iron sucrose in patients with iron deficiency anemia

Iron deficiency anemia (IDA) is common in many chronic diseases, and intravenous (IV) iron offers a rapid and efficient iron correction. This trial compared the efficacy and safety of iron isomaltoside (also known as ferric derisomaltose) and iron sucrose in patients with IDA who were intolerant of, or unresponsive to, oral iron. The trial was an open‐label, comparative, multi‐center trial. Five hundred and eleven patients with IDA from different causes were randomized 2:1 to iron isomaltoside or iron sucrose and followed for 5 weeks. The cumulative dose of iron isomaltoside was based on body weight and hemoglobin (Hb), administered as either a 1000 mg infusion over more than 15 minutes or 500 mg injection over 2 minutes. The cumulative dose of iron sucrose was calculated according to Ganzoni and administered as repeated 200 mg infusions over 30 minutes. The mean cumulative dose of iron isomaltoside was 1640.2 (standard deviation (SD): 357.6) mg and of iron sucrose 1127.9 (SD: 343.3) mg. The primary endpoint was the proportion of patients with a Hb increase ≥2 g/dL from baseline at any time between weeks 1‐5. Both non‐inferiority and superiority were confirmed for the primary endpoint, and a shorter time to Hb increase ≥2 g/dL was observed with iron isomaltoside. For all biochemical efficacy parameters, faster and/or greater improvements were found with iron isomaltoside. Both treatments were well tolerated; 0.6% experienced a serious adverse drug reaction. Iron isomaltoside was more effective than iron sucrose in achieving a rapid improvement in Hb. Furthermore, iron isomaltoside has an advantage over iron sucrose in allowing higher cumulative dosing in fewer administrations. Both treatments were well tolerated in a broad population with IDA.

Bullous Skin Lesions in a Patient with End-Stage Renal Disease and Hepatitis C

Bullous lesions in patients with end-stage renal disease are uncommon and can pose diagnostic and therapeutic challenges. We present a female patient with end-stage renal disease, bullous skin lesions affecting mainly sun-exposed areas, and high ferritin levels. She also had hepatitis C. Her serum porphyrin panel was suggestive of porphyria cutanea tarda. Skin biopsy excluded inflammatory pathologies. Phlebotomy during each hemodialysis, continuation of darbepoetin, and avoidance of any further doses of intravenous iron, with close monitoring of hemoglobin, resulted in a gradual drop in ferritin level and improvement of the skin lesions.

Comparative Risk of Anaphylactic Reactions Associated With Intravenous Iron Products

IMPORTANCE

All intravenous (IV) iron products are associated with anaphylaxis, but the comparative safety of each product has not been well established.

OBJECTIVE

To compare the risk of anaphylaxis among marketed IV iron products.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective new user cohort study of IV iron recipients (n = 688,183) enrolled in the US fee-for-service Medicare program from January 2003 to December 2013. Analyses involving ferumoxytol were limited to the period January 2010 to December 2013.

EXPOSURES

Administrations of IV iron dextran, gluconate, sucrose, or ferumoxytol as reported in outpatient Medicare claims data.

MAIN OUTCOMES AND MEASURES

Anaphylaxis was identified using a prespecified and validated algorithm defined with standard diagnosis and procedure codes and applied to both inpatient and outpatient Medicare claims. The absolute and relative risks of anaphylaxis were estimated, adjusting for imbalances among treatment groups.

RESULTS

A total of 274 anaphylaxis cases were identified at first exposure, with an additional 170 incident anaphylaxis cases identified during subsequent IV iron administrations. The risk for anaphylaxis at first exposure was 68 per 100,000 persons for iron dextran (95% CI, 57.8-78.7 per 100,000) and 24 per 100,000 persons for all nondextran IV iron products combined (iron sucrose, gluconate, and ferumoxytol) (95% CI, 20.0-29.5 per 100,000) , with an adjusted odds ratio (OR) of 2.6 (95% CI, 2.0-3.3; P < .001). At first exposure, when compared with iron sucrose, the adjusted OR of anaphylaxis for iron dextran was 3.6 (95% CI, 2.4-5.4); for iron gluconate, 2.0 (95% CI 1.2, 3.5); and for ferumoxytol, 2.2 (95% CI, 1.1-4.3). The estimated cumulative anaphylaxis risk following total iron repletion of 1000 mg administered within a 12-week period was highest with iron dextran (82 per 100,000 persons, 95% CI, 70.5- 93.1) and lowest with iron sucrose (21 per 100,000 persons, 95% CI, 15.3- 26.4).

CONCLUSIONS AND RELEVANCE

Among patients in the US Medicare nondialysis population with first exposure to IV iron, the risk of anaphylaxis was highest for iron dextran and lowest for iron sucrose.

[Bone and Nutrition. The relationship between iron and phosphate metabolism]

Fibroblast growth factor 23 (FGF23) is an essential hormone for phosphate metabolism. It has been shown that intravenous administration of some iron formulations including saccharated ferric oxide induces hypophosphatemic osteomalacia with high FGF23 levels. On the other hand, iron deficiency promotes FGF23 and induces hypophosphatemia in patients with autosomal dominant hypophosphatemic rickets (ADHR). While iron and phosphate metabolism is connected, the detailed mechanism of this connection remains to be clarified.

[Updates on rickets and osteomalacia: FGF23-mediated hypophosphatemic rickets/osteomalacia]

Some of the hypophosphatemic rickets/osteomalacia are caused by the increased bioactivity of FGF23, and classified into FGF23-mediated hypophosphatemic rickets/osteomalacia. This group includes various disorders such as X-linked, autosomal dominant and autosomal recessive hypophosphatemic rickets/osteomalacia, tumor-induced osteomalacia, and rickets/osteomalacia caused by the administration of iron polymaltose or saccharated ferric oxide. Measurement of serum levels of FGF23 is useful for diagnosis of these conditions. In the adult patients with FGF23-mediated hypophosphatemic rickets/osteomalacia, mineralizing enthesoopathy is an often observed complication.

The effect of intravenous iron on postoperative transfusion requirements in hip fracture patients: study protocol for a randomized controlled trial

BACKGROUND

Anaemia following hip fracture is common. Approximately 30 to 45% of patients have haemoglobin concentrations below population norms on admission, and around 10% are severely anaemic. Anaemia on admission, and in the postoperative period, is associated with poor outcomes with regard to mobility, postoperative mortality and readmission. There is currently no clear consensus on the optimal method of managing perioperative anaemia in this group of frail patients with frequent comorbidity. Liberal red cell transfusion in the postoperative period does not appear to improve outcome, whereas tranexamic acid appears to reduce transfusion rate at the expense of increased cardiovascular morbidity. There are encouraging results from one centre with the use of agents to stimulate red cell production, including intravenous iron and erythropoietin. UK practice differs significantly from these patients and these studies, and it is not clear whether these promising results will translate to the UK population.

METHODS/DESIGN

This is a single-centre randomized controlled parallel group trial, in a British university hospital.Randomization is achieved using a website and computer-generated concealed tables. Participants are 80 patients 70 years or over with acute hip fracture undergoing operative repair. The intervention group receive three daily infusions of 200 mg iron sucrose, starting within 24 hours of admission. The control group receive standard hospital care at the discretion of the clinical team. Red cell transfusions for each group are given in accordance with standard clinical triggers. The primary outcome is an increase in mean reticulocyte count in the intervention group at day 7. Secondary outcome measures include haemoglobin concentrations, early and late transfusion rates, infectious and cardiovascular complications, mobility and 30-day mortality.

DISCUSSION

This is a pilot study to demonstrate haematopoietic efficacy of intravenous iron in this setting. Hence, we have chosen to measure change in reticulocyte count rather than the more clinically relevant differences in haemoglobin concentration or transfusion rate. If our results are positive, the study will provide the necessary information for development of a full-scale trial of intravenous iron.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN76424792; UK Medicines and Healthcare products Regulatory Authority (EuDRACT: 2011-003233-34).

[Importance of the different i.v. iron generations for everyday medical practice]

BACKGROUND

Iron deficiency and anaemia occur in particular in women or as comorbid conditions to a varietyof chronic diseases. Besides oral preparations, parenteral iron therapies are also available for the treatment of iron deficiency or anaemia. In the light of the growing importance and increasing number of parenteral iron preparations, theirpharmacology and application as well as the chronology of their approvals and thecharacteristicsof the various preparations are presented herefor comparison.

METHOD

Review.

RESULTS

To date, there are three different generations of parenteral iron preparations, which differ in terms of stability, safety and dosage. In particular, the active substances of the third generation, ferric carboxymaltose, iron isomaltoside and ferumoxytol are characterised by high complex stability and comparable safety, also allowing rapid application of high doses of iron.

CONCLUSIONS

High molecular weight iron dextran, as a representative of 1st generation iron preparations, should no longer be used if possible, as more recent i.v. iron preparations are available with considerably lower risk of serious anaphylactic reactions. Ferrous gluconate and iron sucrose, as representatives of the 2nd generation, are very efficient preparations, but they require frequent visits to the clinic or the doctor, as they may only be administered in low doses because of labile iron complexes. The three 3rd generation parenteral iron formulations have advantages in handling in everyday practice, since they offer comparably good safety profiles, high complex stability and thus the possibility of rapid application of high doses of iron up to the total cumulative dose. Furthermore, test doses are not required with these preparations, which also simplifies their use.

Iatrogenic osteomalacia: report of two cases

CASE 1: An 80-year-old man presented at our hospital with pain in both knees.He had received continuous intravenous administration of saccharated ferric oxide (SFO) over a period of five years following a diagnosis of iron-deficiency anemia.Blood tests revealed hypophosphatemia (1.4 mg/dl) and high circulating levels of fibroblast growth factor 23 (FGF23) at 248.8 mg/dl.These findings led to the diagnosis of FGF23-related osteomalacia due to SFO administration.Accordingly, the treatment plan was first to discontinue SFO, which led to a decrease in pain and normalization of phosphorus and FGF23 after 1 month.CASE 2: A 63-year-old woman presented at our hospital with leg pain.She had undergone total gastrectomy for gastric cancer at 36 years of age.Blood tests revealed hypocalcemia (8.3 mg/dl) and hypophosphatemia (2.2 mg/dl), and 25(OH)D at no more than 5 pg/ml.Bone X-rays showed significantly diminished bone shadowing.These findings led to a diagnosis of vitamin D-deficient osteomalacia due to impaired absorption following total gastrectomy.For therapy, she was treated with 1 μg/day oral alfacalcidol.Two months after initiating treatment, the pain improved.

CONCLUSION

When a patient is diagnosed with unexplained pain, it is important to pay attention to the possibility of an iatrogenic etiology.

Comparison of adverse event profile of intravenous iron sucrose and iron sucrose similar in postpartum and gynecologic operative patients

OBJECTIVE

Severe iron deficiency resulting in anemia is a common problem during pregnancy and in menstruating women. Several choices for IV iron replacement therapies exist and increased pressures on budgets may require cheaper 'iron sucrose similar' (ISS) to be used. In our practice, an iron sucrose similar (Ferex; ISS(FRX)) was introduced to reduce costs in the treatment of pregnant women or those planned for surgery. Post several months of use we observed increased rates of adverse events from patients and hence performed this analysis to confirm these findings.

METHODS

Data on adverse events was retrospectively collected from 658 patients treated between September 2004 and December 2011. Patients were analyzed in three cohorts, iron sucrose originator (IS(ORIG)), ISS(FRX) diluted in 100 mL saline and ISS(FRX) diluted in 200 mL saline.

RESULTS

The mean age was 38.5 years and included patients having normal delivery, Cesarean section, myomectomy, hysterectomy, cystectomy and adnexectomy. There were 169 patients in the IS(ORG) group and 210 and 279 in the ISS(FRX)-100 and ISS(FRX)-200 groups respectively. Adverse drug reactions were more frequent in the ISS(FRX) groups vs. IS(ORIG) (11.0 vs. 14.3 vs. 1.8%; p < 0.02). Events were mild-to-moderate in nature and were predominately injection site reactions and phlebitis.

RESULTS

may be impacted by imbalance in baseline characteristics and cumulative iron dose received, however events were mostly acute and all patients received 200 mg iron as single administration.

CONCLUSION

This is the first large analysis suggesting increased adverse events due to an ISS. For our practice, the use of ISS(FRX) was discontinued owing to safety concerns outweighing the theoretical cost benefit. This study raises the question on the appropriate approval process for complex drugs and if these can be substituted without appropriate clinical testing, both for efficacy and most importantly safety, in routine clinical practice.

Fatal anaphylactic reaction to iron sucrose in pregnancy

Iron-deficiency anemia in pregnancy can have serious deleterious effects for both mother and fetus. Parenteral iron therapy in iron-deficiency anemia is recommended in patients where oral iron therapy is ineffective due to malabsorption states and non-compliance. Compared to oral iron therapy, intravenous iron results in much more rapid resolution of iron-deficiency anemia with minimal adverse reactions. Iron sucrose has a favorable safety profile and is an alternative to other forms of parenteral iron therapy in correction of iron stores depletion. Immune mechanisms and iron agent releasing bioactive, partially unbound iron into the circulation, resulting in oxidative stress appears to cause severe adverse reactions. Although iron sucrose has a favorable safety profile in comparison to other parenteral iron preparations, this report highlights a fatal anaphylactic shock to iron sucrose in a pregnant woman with severe iron deficiency non-compliant to oral iron therapy.

Comparative rates of adverse events with different formulations of intravenous iron

Oral iron replacement is the standard therapy in iron-deficiency anemia (IDA). However, 59% of patients have gastrointestinal toxicity. With impaired iron uptake from the gastrointestinal tract (in anemia of chronic disease (ACD) or after bariatric surgery), suboptimal responsiveness to exogenous erythropoietin (in chronic renal failure), in patients with cancer receiving chemotherapy, or when oral iron is poorly tolerated, IV iron therapy is the preferred mode of repletion. Although effective in increasing hemoglobin, the relative safety of the available IV iron preparations is not well documented. We examined the comparative safety of IV iron formulations used at hospitals associated with our institution. Among 619 unique patients who received IV iron over a 2-year period, we found 32 adverse events (AEs), ranging from urticaria to chest pain. There were no serious AEs or anaphylactic-type reactions. In a multivariate model, there was no difference in AE rates between low-molecular-weight iron dextran (LMWD) and ferric gluconate; however, iron sucrose had significantly higher odds ratio of AEs (OR = 5.7; 95% CI = 1.6–21.3). Our data suggest that AE rates with IV iron are acceptable. More widespread use of LMWD, in particular, which can be given safely as a total dose infusion (TDI), should be considered.

Clinical case reports raise doubts about the therapeutic equivalence of an iron sucrose similar preparation compared with iron sucrose originator

Intravenous iron sucrose has been used to treat iron deficiency and iron deficiency anaemia associated with different chronic diseases for several decades. Despite the complex structure of iron sucrose, copies called iron sucrose similars (ISSs) have been approved according to the generic approach and therefore, therapeutic equivalence is taken for granted. In February 2011, three patients who previously tolerated well the prescribed iron sucrose originator experienced urticaria, oedema and headache within 1 hour after infusion of an ISS that had been substituted for the originator at the pharmacy level. One patient collapsed due to severe hypovolaemic dysregulation and required hospitalisation. Due to emerging evidence that ISSs differ from the iron sucrose originator in safety and efficacy profiles, it seems prudent for physicians as well as patients who require intravenous (i.v.) iron to have available data on therapeutic equivalence of new ISS preparations versus the originator. This may be especially important in patients who are chronically ill and need iron supplementation on a regular, long-term basis.

Fibroblast growth factor 23-related osteomalacia caused by the prolonged administration of saccharated ferric oxide

A 44-year-old woman with iron deficiency anemia was on a continuous course of intravenous saccharated ferric oxide (SFO). She came to our hospital because of right hip joint pain. She was found to have hypophosphatemia caused by impaired phosphorus resorption and her fibroblast growth factor 23 (FGF-23) levels were elevated. Therefore, she was diagnosed with FGF-23-related osteomalacia due to SFO administration. Discontinuation of the SFO treatment rapidly improved the impaired phosphorus resorption and also normalized the blood levels of phosphorus and FGF-23. During the treatment with SFO, it is important to regularly measure the blood levels of phosphorus in order to prevent the occurrence of osteomalacia.

[Experimental systemic enzyme therapy of gouty and primary glomerulonephritis]

The influence of a systemic enzymotherapy on the morphological, biochemical, and functional manifestations of the kidney damage during the experimental gouty and primary glomerulonephritis is described in comparison to the results obtained by traditional methods.