Medication practice in hospitals: are nanosimilars evaluated and substituted correctly?

INTRODUCTION: This study investigates the drug selection and dispensing behaviour of hospital pharmacists of intravenous iron products including iron sucrose and iron sucrose similar, with special emphasis on substitution and interchangeability in France and Spain. Iron-carbohydrate complex drugs represent different available intravenous iron drugs and are part of the non-biological complex drug (NBCD) class, an expanding drug class with up to 30 brands available in intravenous pharmacotherapy and over 50 in clinical development. Follow-on versions of iron sucrose have appeared in some markets such as France and Spain, which were authorised by the generic approval pathway. However, differences in clinical efficacy and safety of iron sucrose similars compared with the reference originator drug Venofer have been observed, putting a question mark on their equivalence as assessed for authorisation and consequently their substitutability and interchangeability.

METHOD: 70 French and 70 Spanish hospital pharmacists were surveyed via an online questionnaire on their formulary selection and dispensing behaviour of intravenous iron medicines.

RESULTS: There is little awareness about the characteristics of this class of drugs and the reported differences in safety and efficacy between iron sucrose and iron sucrose similars. In approximately 85% of cases the intravenous iron is chosen according to the hospital formulary. In 30% (France) and 34% (Spain) of cases an iron sucrose similar was dispensed because the formulary requires dispensing an alternative lower cost drug when available. In 26% (France) and 52% (Spain) of cases the physician is not informed on such a medication change using a similar product.

CONCLUSIONS: Evaluation of NBCD similars for substitution and interchange by hospital pharmacists is rarely based on scientific and clinical criteria but rather on cost aspects only, which does not ensure safe, efficacious and cost-effective use of such drugs.