Clinical case reports raise doubts about the therapeutic equivalence of an iron sucrose similar preparation compared with iron sucrose originator.

Intravenous iron sucrose has been used to treat iron deficiency and iron deficiency anaemia associated with different chronic diseases for several decades. Despite the complex structure of iron sucrose, copies called iron sucrose similars (ISSs) have been approved according to the generic approach and therefore, therapeutic equivalence is taken for granted. In February 2011, three patients who previously tolerated well the prescribed iron sucrose originator experienced urticaria, oedema and headache within 1 hour after infusion of an ISS that had been substituted for the originator at the pharmacy level. One patient collapsed due to severe hypovolaemic dysregulation and required hospitalisation. Due to emerging evidence that ISSs differ from the iron sucrose originator in safety and efficacy profiles, it seems prudent for physicians as well as patients who require intravenous (i.v.) iron to have available data on therapeutic equivalence of new ISS preparations versus the originator. This may be especially important in patients who are chronically ill and need iron supplementation on a regular, long-term basis.