Ferric Gluconate Maintenance Dosing
For hemodialysis patients requiring maintenance iron therapy, administer 25 to 125 mg of ferric gluconate IV once weekly, with the goal of maintaining transferrin saturation ≥20% and serum ferritin ≥100 ng/mL. 1
Standard Maintenance Regimen
The typical maintenance dose varies based on individual iron losses and erythropoietic demand:
- Weekly dosing range: 25-125 mg IV once per week 1
- Alternative schedules: Can provide 250-1,000 mg within 12-week periods using various frequencies (three times weekly, twice weekly, weekly, or every other week) 2, 3
- Most common approach: 125 mg IV weekly for 8 consecutive weeks (total 1,000 mg), then adjust based on iron parameters 4, 5
Administration Guidelines
Infusion protocol for the standard 125 mg maintenance dose:
- Dilute in 50-100 mL of 0.9% sodium chloride 4
- Infuse over 30-60 minutes (approximately 2.1-4.2 mg/min) 4
- Can also give undiluted as slow IV push at rate up to 12.5 mg/min 5
- Do not exceed 125 mg per dose per FDA labeling 5
Monitoring Requirements
Iron parameters should be checked every 3 months during maintenance therapy to guide dosing adjustments: 1, 2, 3
- Target TSAT: ≥20% 1, 2
- Target ferritin: ≥100 ng/mL 1, 2
- Upper safety limits: Hold iron if TSAT >50% or ferritin >800 ng/mL 1
Critical timing consideration: Do not measure iron parameters within 2-7 days after administration of 100-125 mg doses, as values will be spuriously elevated 4
Dose Adjustment Algorithm
When TSAT >50% and/or ferritin >800 ng/mL:
- Withhold IV iron for up to 3 months 1
- Re-measure iron parameters before resuming 1
- When resuming, reduce weekly dose by one-third to one-half 1
When TSAT <20% and/or ferritin <100 ng/mL despite maintenance therapy:
- Increase to repletion dosing: 125 mg IV for 8 consecutive hemodialysis sessions 1, 5
- Reassess after completing course 1
Special Populations
Pediatric patients (≥6 years):
- 1.5 mg/kg (0.12 mL/kg) diluted in 25 mL saline, infused over 1 hour per dialysis session 5
- Maximum dose: 125 mg 5
Peritoneal dialysis patients:
- Same dosing as hemodialysis patients, but administered once every 4 weeks after initial repletion 6
- Oral iron typically inadequate; IV iron preferred 1
Important Safety Considerations
No test dose required for ferric gluconate, unlike iron dextran 3, 4
Contraindications:
Monitoring post-infusion:
- Observe for at least 30 minutes after administration 2, 5
- Monitor for hypotension, which occurs in approximately 2% of administrations 5
Common Pitfalls to Avoid
- Do not use oral iron concurrently with IV maintenance therapy—it provides no additional benefit and increases side effects 4
- Do not measure iron studies immediately after dosing—wait at least 7 days for accurate assessment 4
- Do not routinely exceed 125 mg per dose—postmarketing data shows higher doses (>125 mg) associated with increased adverse events, though research suggests 250 mg doses are safe in selected patients 5, 7, 8
- Do not continue iron when ferritin >800 ng/mL or TSAT >50%—this increases risk of iron overload without improving erythropoiesis 1
Evidence Quality Note
The NKF-K/DOQI guidelines 1 provide the foundational framework for ferric gluconate maintenance dosing, though they date from 2001. The FDA labeling 5 reinforces the 125 mg maximum per dose recommendation. Research studies 7, 8, 6 demonstrate that higher doses (250 mg) are safe and well-tolerated, but this remains off-label. For standard practice, adherence to the FDA-approved 125 mg maximum per dose is recommended, with weekly administration adjusted based on iron parameters.