Evaluation of Minimal Optimal Dose of Intravenous Ferric Carboxymaltose for Treatment of Iron Deficiency Anemia and Risk of Transient Hyperferritinemia

BACKGROUND: Iron supplementation is administered orally or intravenously to treat iron-deficiency anemia (IDA). Ferric Carboxymaltose (FCM) “Ferinject(®)” is an intravenous (IV) iron preparation that has emerged as a safe therapeutic option for treating IDA in the past decade. AIM: This study aimed to evaluate safety and efficacy of carboxymaltose in a cohort of patients with IDA not responding to oral therapy. METHODS: This 12-month retrospective study included 106 patients with IDA, with-or without bariatric surgery, who received (single or multiple doses) of Carboxymaltose 500mg/10mL. Data points included patients’ demographics, baseline data for Hb, platelet, ferritin, and MCV pre–and at 1, 2, and 3 months following different doses of IV-Carboxymaltose. Changes in Hb, MCV, platelets, and ferritin levels were recorded in response to Carboxymaltose to assess the optimal dose, risk of hyperferritinemia, and hypophosphatemia. RESULTS: At three months (95 days) follow-up, the median change pre-and post-therapy in hemoglobin was from 9.5 to 11.9g/dL (p < 0.01), MCV 73.6–80.5fL (p < 0.01), and ferritin 5.3–93.8ng/mL. A significant difference was observed between platelet count of patients who underwent bariatric surgery and those who did not. An optimal ferritin response (>30ng/mL) was observed in 87.8% of patients who received first dose, and none of the full three doses showed no response. 37% of patients who received two doses developed hyperferritinemia. Serum phosphate levels were assessed in 28 cases, and hypophosphatemia was observed in 25% of these patients. CONCLUSION: Carboxymaltose is a reliable option for IDA. IV-FCM therapy helps achieve significant improvement in hemoglobin concentration and MCV from the first dose carrying a low reversible risk of hyperferritinemia following multiple doses. An interesting finding of this study is the discovery of a population of IDA patients requiring periodic assessment for iron reinfusion to sustain normal levels, mostly post-bariatric surgery. Changes in serum phosphate levels reported to occur consecutively with FCM treatment should be further studied.