Diebold M, et al. - Researchers investigated whether and to what extent smaller intravenously (IV) administered iron doses to maintain adequate stores in hemodialysis patients result in transient spurious elevations of ferritin and transferrin saturation (TSAT). Participants were hemodialysis patients on a stable maintenance ferric carboxymaltose (FCM) dosing regimen of 100 mg or 200 mg every four weeks. Following the administration of FCM, serial assessments of ferritin and TSAT were performed over 4 weeks. In patients who received 100 mg FCM (n = 19), an increase in ferritin values by 113 ± 72.2 μg/l from baseline to the peak value was noted and these values continued to rise remarkably until two weeks after the administration. Increase in ferritin values, by 188.5 ± 67.56 μg/l, was evident and this remained significantly elevated by the end of week three in patients who received 200 mg FCM (n = 12). Dose-dependent transient ferritin elevations of extended duration were seen in relation to IV administration of FCM at doses of 100 or 200 mg in hemodialysis patients. A recommendation was made for temporal coordination of blood sampling for iron status evaluation with the maintenance IV iron dosing schedule.