The use of the same International Nonproprietary Name (INN) for different drug products may lead to inaccurate reporting of adverse events, resulting in masking of potential differences between products. This issue is of particular concern for products that have not undergone approval via biosimilar regulatory pathways that are aligned with World Health Organization Similar Biotherapeutic Product guidelines.

This analysis shows evidence of combined and intercalated use of different products sharing the same INN. The use of the identical INN may thus cause a misperception of the interchangeability of the drug products that were not approved as biosimilars.

Data from this study support the critical need for enforcing the World Health Organization INN naming guidelines to distinguish different drug products. It points to the necessity of creating an adequate and clear regulation and reporting system for safety events.