The RxNorm API finds related concepts by tracing RxNorm relationships over multiple steps. A table of RxNav's "default paths" from one concept term-type to another can be found in the RxNav Overview's discussion of the RxNav graph view.

Paths relating BPCK and clinical-drug and ingredient term types, in both directions, have been simplified and made more consistent. The new paths traverse GPCK instead of taking the union of sub-paths via SBD and SCD. There is no change to the relations found by paths beginning with BPCK. The new paths in the other direction, ending with BPCK, match those results and thus may yield more BPCKs than before.

The path from SBDG to BN was simplified by the removal of SBD as an intermediate node. The new path returns relations consistent with the BN to SBDG path, and thus may yield more BNs than before.

The following table lists the changes made to the default paths.