LOW-DOSE INTRAVENOUS IRON ADMINISTRATION IN CHRONIC HEMODIALYSIS PATIENTS TREATED WITH RECOMBINANT HUMAN ERYTHROPOIETIN

Abstract

We conducted a prospective study to determine the effect of intravenous low-dose iron administration in chronic hemodialysis patients treated with recombinant human erythropoietin (rHuEPO). Sixteen hemodialysis patients (8 males and 8 females; mean age 63.1±9.8 years) on maintenance rHuEPO therapy were included in the study. Patients with <100 ng/ml of ferritin received 50 mg iron during every hemodialysis session. Patients with 100–200 ng/ml of ferritin were given 50 mg iron fortnightly. Iron was not supplemented in patients with ferritin levels >200 ng/ml. Mean hematocrit, serum iron levels and transferrin saturations were significantly higher at 6 and 12 months. There was a significant reduction in weekly rHuEPO doses between the start and the 6th and 12th months. Our study shows intravenous iron administration of 100 mg/month may be sufficient to achieve a satisfactory iron status in dialysis patients on maintenance rHuEPO therapy.

• Intravenous iron
• Chronic hemodialysis patients
• Recombinant human erythropoietin

In most hemodialysis patients, oral iron agents neither improve nor sustain long-term iron balance [[1]]. Intravenous administration of iron during hemodialysis is becoming a standard of therapy to maintain adequate iron levels in patients on chronic hemodialysis [[2]]. We conducted a prospective study to determine the effect of intravenous low-dose iron administration in chronic hemodialysis patients treated with recombinant human erythropoietin (rHuEPO).

Sixteen hemodialysis patients (8 males and 8 females; mean age 63.1 ± 9.8 years) on maintenance rHuEPO therapy were included in the study. The dose of iron supplementation (saccharated ferric oxide) was determined according to the ferritin level. Patients with <100 ng/ml of ferritin received 50 mg iron during every hemodialysis session. Patients with 100–200 ng/ml of ferritin were given 50 mg iron fortnightly. Iron was not supplemented in patients with ferritin levels >200 ng/ml.

Hematocrit was determined weekly; serum iron, serum ferritin and transferrin saturation were measured monthly. All data were expressed as mean values ± S.D. Student's t test was used and p<0.05 was considered significant.

Mean hematocrit, serum iron levels and transferrin saturations were significantly higher at 6 and 12 months. A difference in rHuEPO doses was not found between the start and the 3rd month. There was a significant reduction in weekly rHuEPO doses between the start and the 6th and 12th months (Table 1). Iron supplements of 50 mg fortnightly were given to 13 of the 16 patients for 6 months. 7 patients received an iron supplement of 50 mg fortnightly for 12 months.

Table 1. Laboratory Findings and Treatment Doses (Mean±S.D.)

	Start	3rd Month	6th Month	12th Month
Hct (%)	26±2.3	28.1±1.4	1*30.0±2.1	1*29.9±1.1
Serum iron (µg/dl)	44±12.0	48±8.4	1*59.0±4.4	1*64±5.2
Serum ferritin (ng/ml)	84.4±28.4	100.5±13.8	1*139.3±18.1	1*189.8±52.4
Transferrin saturation (%)	22.0±7.4	26.4±4.2	1*34.1±6.2	1*32.3±6.1
rHuEPO dose (U/week)	6000±1200	5800±1000	1*5000±1200	1*4500±800

*p<0.05.

Maintenance intravenous iron administration maximizes the erythropoietic response in dialysis patients receiving rHuEPO and causes a reduction in rHuEPO requirements [[2]]. The optimal protocol for intravenous iron administration in dialysis patients remains to be established. MacDougall et al. reported that the administration of 100 mg iron twice a week (800 mg/month) for 4 months was sufficient to replete iron stores [[3]]. Fishbane et al. recommended the administration of 250 mg iron fortnightly (500 mg/month) for 4 months [[4]]. Recently, intravenous low-dose iron administration of 40 mg fortnightly (80 mg/month) was reported to be adequate for the maintenance of iron stores in patients on rHuEPO therapy [[3]].

Our study shows intravenous iron administration of 100 mg/month may be sufficient to achieve a satisfactory iron status in dialysis patients on maintenance rHuEPO therapy. Low-dose iron supplementation seems to be reasonable in patients on long-term dialysis to avoid increased risk of infections, cardiovascular disease and malignancy due to iron overload.