HL7 v2 RXR-1 (Route): Format, Values, and Testing Notes
RXR-1 is the one field in the segment that almost every system populates, which is exactly why a bad route code is so easy to miss — the field is never blank, it is just sometimes wrong.
RXR-1 is a coded element (CE/CWE) identifying how the substance was administered — for example orally, intramuscularly, intravenously, or topically. It is typically drawn from a locally adopted route table, with each value carrying a code, a display name, and a coding system identifier.
What this field contains
Example
RXR-1 carries IM^Intramuscular^HL70162 — code, display text, and coding system components for a synthetic intramuscular administration.
Where this trips people up
Test data generators frequently hardcode a single route value, so parsing logic that only ever sees IM never gets exercised against oral, topical, or subcutaneous routes. That gap surfaces when a real feed sends a route the mapping table doesn't recognize, and the record either gets rejected outright or silently defaults to the wrong route in a downstream display — a discrepancy nobody notices until a chart audit flags a dose that says it was swallowed when it was actually injected.