Product Substitution Best Practices

Before automatically substituting, it would be wise to review a product’s therapeutic equivalence. Drugs approved under a New Drug Application (NDA), or Abbreviated New Drug Application (ANDA), will be found in the FDA Orange book and use Therapeutic Equivalency (TE) Codes to establish equivalency ratings. Biologics, on the other hand, are approved under a Biologic License Application (BLA) and will be found in the FDA Purple Book. The Purple Book does not use TE codes, but rather matching color cards and category headers to indicate biosimilars and interchangeable biosimilars.

Beyond the TE Codes (primarily used to identify generic equivalents), compare the original product’s NDA to the NDA of the product you are looking to substitute. To continue with the ProAir^® example, consider the NDA of both ProAir^® HFA and ProAir RespiClick^®:

Since the NDA numbers do not match, it would be appropriate to obtain prescriber approval and document authorization to substitute the ProAir RespiClick^® for the ProAir^® HFA. When requesting the change, consider obtaining a new order to help mitigate audit risk. Substituting the RespiClick on the same Rx Number has a higher likelihood to flag for potential audit.

PAAS Tips:

• Refer to January 2021 Newsline article, Biologic Drug Substitution Best Practices- Do I Need to Call the Prescriber? for tips on how to determine if biologic products can be substituted
• Reference the April 2019 Newsline article, Authorized Generic vs. ANDA Generic to answer questions regarding the difference between each product type
• If there is any doubt about whether a product can be substituted, it would be best to err on the side of caution and contact the prescriber for approval.