Dosing and uses of Ferric citrate (Auryxia)
Adult dosage forms and strengths
tablet
- 210mg ferric iron (equivalent to 1g ferric citrate)
Hyperphosphatemia
Indicated for the control of serum phosphorus levels in patients with chronic kidney disease on dialysis
Initial: 420 mg (as ferric iron [ie, 2 tablets]) PO TID with meals
Monitor serum phosphorus levels and adjust dose at ≥1-week intervals in decrements or increments of 1 to 2 tablets/day PRN to maintain serum phosphorus at target levels
Not to exceed 12 tablets/day
Administration
Take with meals
Pediatric dosage forms and strengths
Safety and efficacy not established
Ferric citrate (Auryxia) adverse (side) effects
>10%
Diarrhea (21%)
Nausea (11%)
1-10%
Constipation (8%)
Vomiting (7%)
Cough (6%)
Warnings
Contraindications
Iron overload syndromes (eg, hemochromatosis)
Cautions
Iron absorption from ferric citrate may lead to excessive elevations in iron stores
Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children younger than 6 yr; keep out of the reach of children
Patients with inflammatory bowel disease or active, symptomatic GI bleeding were excluded from clinical trials; safety has not been established in these populations
Pregnancy and lactation
Pregnancy category: B
Lactation: Unknown if distributed in human breast milk
Data from rat studies have shown the transfer of iron into milk by divalent metal transporter-1 (DMT-1) and ferroportin-1 (FPN-1)
Hence, there is a possibility of infant exposure when ferric citrate is administered to breastfeeding women
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Ferric citrate (Auryxia)
Mechanism of action
Phosphate binder; ferric iron binds dietary phosphate in the GI tract and precipitates as ferric phosphate, which is insoluble and is excreted in the feces
By binding phosphate in the GI tract and decreasing absorption, ferric citrate lowers the phosphate concentration in the serum
Absorption
Shown to increase serum iron parameters, including ferritin, iron, and TSAt
In a 52-week clinical trial, mean ferritin levels rose from 593 ng/mL to 895 ng/mL, mean TSAT levels rose from 31% to 39%, and mean iron levels rose from 73 mcg/dL to 88 mcg/dL
