For the /MedicationRequest endpoint, we initially planned to use RxNorm codes only. However, we have encountered cases where certain medications do not have an RxNorm code. Instead, we are receiving Cerner-specific codes. We are seeking guidance on how to match these Cerner codes against RxNorm codes and whether there is an available API or standard method to perform this mapping.
Cerner has clarified that when an order is placed in their Millennium system, RxNorm codes are not used directly. Instead, Cerner relies on the Multum drug database internally. During outbound communication, Cerner translates Multum codes into RxNorm codes, and for inbound requests, any RxNorm code received is translated back into a Multum drug code for internal use.
When writing data to Millennium, Cerner restricts the term types (TTY) to those that can be mapped to Multum drug content. The supported RxNorm term types for this purpose are: Ingredient (IN), Multiple Ingredients (MIN), Semantic Clinical Drug (SCD), Semantic Branded Drug (SBD), Generic Pack (GPCK), Branded Pack (BPCK), and Brand Name (BN).