Dose reduction or closer monitoring of renal and hepatic function also recommended during periods of treatment with high doses and when serum ferritin levels are close to target range. If serum ferritin falls consistently below 500 µg/l (in transfusional iron overload) or below 300 µg/l (in non‑transfusion‑dependent thalassaemia syndromes), SPC advises interruption of treatment should be considered.