Date Published: 
Monday, 11 August, 2014

Single-dose ferric carboxymaltose improves fatigue, mental QoL, cognitive function and erythropoiesis in iron deficient women, according to PREFER study

Single-infusion ferric carboxymaltose improves symptoms of fatigue in iron deficient women with normal or borderline haemoglobin, new data reveal. The PREFER trial (Ferric Carboxymaltose Treatment to Improve Fatigue Symptoms in Iron-deficient Non-anaemic Women of Child Bearing Age) also demonstrates that ferric carboxymaltose may improve mental quality of life (QoL), cognitive function and erythropoiesis compared with placebo. Researchers suggest that ferric carboxymaltose may be an effective treatment alternative in patients who cannot tolerate or use oral iron.

Unexplained fatigue is a major health problem, affecting approximately 25% of patients in primary care1. Similar to reduced physical performance and cognitive function, fatigue is closely associated with anaemia and iron deficiency2, which are leading causes of disability and contribute substantially to global burden of disease3.

The PREFER study included 290 women with unexplained fatigue (Piper Fatigue Scale [PFS] score ≤5), iron deficiency (ferritin <50 mg/L and transferrin saturation <20%, or ferritin <15 mg/L) and normal or borderline haemoglobin (≥115 g/L). The PFS is used to evaluate and monitor patients’ fatigue and overall condition. Patients were randomised to receive either 1000 mg of single-dose ferric carboxymaltose (n=144) or saline (placebo) infusion (n=146). The primary endpoint was the proportion of patients with reduced fatigue (≥1 point decrease in PFS score from baseline to Day 56).

The percentage of patients with improved PFS score was significantly higher in the ferric carboxymaltose group than in placebo (65.3 vs 52.7%, respectively; p=0.03). A 50% reduction of PFS score was achieved in significantly more patients treated with iron compared with placebo (33.3 vs 16.4%, respectively; p<0.001). Haemoglobin levels ≥120 g/L were reached by all patients in the ferric carboxymaltose group compared with 81% in the placebo group (difference of 19.2%; 95% CI: 12.8, 25.6; p<0.001). Mental QoL and cognitive function scores also showed a larger improvement in the ferric carboxymaltose group.

An increase in the reticulocyte count (at Days 7 and 28) and a decrease in the soluble transferrin receptor, in the ferric carboxymaltose group compared with placebo, were also observed. The authors put forward the idea that this may indicate enhanced erythropoiesis in the ferric carboxymaltose group, as a result of iron repletion.

Oral iron therapy has several limitations including delayed time to response (particularly in cases of recurrent blood loss such as in menstruating women), gastrointestinal side effects, low adherence to therapy, and lack of improvement in QoL. Single-infusion ferric carboxymaltose may be an effective treatment alternative, the researchers state, independent of haemoglobin levels. Accurate iron assessment in women with unexplained fatigue may prevent incorrect diagnosis and improve treatment of iron deficiency.

The full article is available in the April 2014 issue of PLoS One. For information on iron therapy in women, please click here.