Fericit

Approved Indications:

• Control of Serum Phosphorus in CKD on Dialysis:
  Ferric citrate is indicated to control serum phosphorus levels in adult patients with chronic kidney disease (CKD) on dialysis (hemodialysis or peritoneal dialysis).
• Iron Deficiency Anemia in CKD not on Dialysis:
  Indicated for the treatment of iron deficiency anemia in adult patients with CKD not on dialysis when oral iron supplements alone are insufficient or not tolerated.

Clinically Accepted Off-Label Uses:

• There are no widely supported off-label indications for ferric citrate beyond its approved uses in CKD-related hyperphosphatemia and iron deficiency anemia.

Adults:

• For Hyperphosphatemia in CKD on Dialysis:
• Initial dose: 2 tablets (each containing 210 mg ferric iron) 3 times daily with meals.
• Titration: Adjust by 1–2 tablets daily as needed to maintain target serum phosphorus.
• Maximum daily dose: 12 tablets per day.
• For Iron Deficiency Anemia in CKD not on Dialysis:
• Initial dose: 1 tablet 3 times daily with meals.
• Titrate based on serum ferritin, transferrin saturation (TSAT), and hemoglobin levels.
• Maximum daily dose: 12 tablets per day.

Pediatrics:

• Not approved for pediatric use. Safety and efficacy have not been established.

Geriatric:

• No specific dose adjustment is required based on age alone. However, monitor iron parameters carefully due to age-related organ function changes.

Renal Impairment:

• Approved for use in CKD patients. Dose is individualized based on serum phosphorus and iron parameters. No separate adjustment beyond clinical monitoring is required.

Hepatic Impairment:

• No formal recommendations for dose adjustment. Use with caution in severe liver disease, as excessive iron accumulation may occur.

Route & Administration:

• Oral administration only.
• Must be taken with meals to ensure phosphate binding.
• Swallow whole; do not crush or chew.

Ferric citrate works via a dual mechanism. In the gastrointestinal tract, the ferric iron component binds dietary phosphate, forming insoluble ferric phosphate complexes that are excreted in feces, effectively lowering serum phosphate levels in patients with CKD. Simultaneously, a portion of the ferric iron is absorbed through the intestinal lining and becomes available for systemic iron replacement, replenishing depleted iron stores and increasing hemoglobin in patients with iron deficiency anemia. This combined phosphate-binding and iron-replenishing action is particularly beneficial for CKD patients who often have both conditions concurrently.

Absorption:

• Approximately 1%–2% of the administered ferric iron is absorbed systemically.
• Food enhances the phosphate-binding effect but does not significantly affect iron absorption at therapeutic doses.

Distribution:

• Absorbed iron is incorporated into ferritin and hemosiderin in the liver, bone marrow, and reticuloendothelial system.
• Iron becomes part of hemoglobin and other iron-containing proteins.

Metabolism:

• Ferric iron is reduced to ferrous iron in the intestinal mucosa and follows the body’s normal iron metabolic pathways, including incorporation into hemoglobin or storage.

Excretion:

• Bound phosphate is eliminated in feces.
• Excess absorbed iron is stored; minimal elimination occurs via sweat, desquamation, or sloughing of gastrointestinal epithelial cells.

Onset of Action:

• Phosphate binding occurs locally in the GI tract during digestion.
• Iron replenishment may take several weeks to produce significant increases in hemoglobin.

Half-Life:

• Not applicable for the product as a whole; once absorbed, iron is handled by normal body iron turnover processes (RBC lifespan ~120 days).

Pregnancy:

• There is insufficient well-controlled data in pregnant women. Iron is essential during pregnancy, but excessive iron intake can pose risks such as iron overload. Use only if clearly needed and if the expected benefit justifies potential risk.

Lactation:

• Small amounts of iron may be excreted in human milk. No significant adverse effects in breastfed infants have been reported with maternal iron supplementation. Monitor the infant for potential GI effects.

General:

• Caution is advised due to limited human data. Maternal iron status and clinical necessity should guide use.

• Primary Class: Phosphate Binder
• Secondary Class: Oral Iron Replacement Therapy

• Known hypersensitivity to ferric citrate or any excipients.
• Iron overload disorders (e.g., hemochromatosis, hemosiderosis).
• Evidence of significant iron accumulation.
• Active gastrointestinal bleeding if iron absorption might exacerbate iron loading.

• Iron Overload: Risk of iron accumulation; monitor serum ferritin and TSAT regularly. Discontinue if iron indices exceed target levels.
• GI Adverse Effects: Diarrhea, constipation, or dark stools may occur. Dark stools may mask signs of GI bleeding.
• Laboratory Monitoring: Regularly check serum phosphorus, ferritin, TSAT, and hemoglobin.
• Use in Pediatrics: Not established; avoid use unless specifically directed by a specialist.
• Black Box Warning: None currently.

Common (≥5%):

• Gastrointestinal: Diarrhea, nausea, constipation, abdominal discomfort, dark-colored stools.

Less Common but Clinically Significant:

• Iron overload (with prolonged use or excessive dosing).
• Hypersensitivity reactions (rare).

Serious or Rare:

• Significant iron accumulation leading to iron toxicity.
• Severe GI bleeding if an underlying GI lesion is present but masked by dark stools.

Onset:

• GI side effects generally appear early in treatment. Iron overload develops gradually with chronic overuse.

• Aluminum-, magnesium-, or calcium-containing antacids: May interfere with phosphate binding.
• Oral tetracyclines and fluoroquinolones (e.g., doxycycline, ciprofloxacin): Reduced absorption; separate doses by at least 2 hours.
• Levothyroxine: May reduce thyroid hormone absorption; separate dosing times.
• Food: Should be taken with food for proper phosphate binding.
• Alcohol: No direct interaction but may exacerbate GI irritation.

Enzyme Involvement:

• Not a CYP450 substrate; minimal CYP-mediated interactions.

• No major changes to indication or dosing in recent FDA, EMA, or KDIGO updates.
• Emphasis remains on regular monitoring of iron stores to prevent overload.
• Still included in KDIGO and other CKD-MBD guidelines for managing hyperphosphatemia and iron deficiency in CKD.

• Temperature: Store at 20°C to 25°C (68°F to 77°F); excursions permitted between 15°C–30°C (59°F–86°F).
• Humidity: Keep bottle tightly closed and store in a dry place.
• Light Protection: Standard amber containers are used; protect from excessive moisture.
• Special Handling: Do not crush or chew tablets.
• Reconstitution: Not applicable.