HL7 RXR Segment: Pharmacy / Treatment Route

The RXR segment states how a medication or treatment is given: the route (RXR-1), the body site, the device, and the method of administration. It accompanies the pharmacy order and give/dispense/administration detail segments — one RXR per route — telling the receiving system whether a drug is taken orally, injected intramuscularly, infused intravenously, and where on the body it is administered.

Purpose

RXR conveys the administration route and the related site, device, and method for a pharmacy or treatment order. RXR-1 (Route) is the single required field; the remaining fields refine where and how the substance is delivered. The segment is route-specific and may repeat when an order supports more than one route.

Used in

RXR appears in pharmacy and treatment messages alongside the order and administration detail segments: pharmacy order messages (RDE, OMP) after RXO/RXE, treatment administration (RAS) after RXA, and immunization messages (VXU) after RXA. See ORM and VXU.

Field-by-field reference

Source: the official HL7 v2-to-FHIR IG (RXR to MedicationRequest). R = required (cardinality min ≥ 1). Repeat = field may repeat. Length is not carried by the FHIR source and is shown as —; Table # values are the established HL7 v2 table bindings for these fields.

Most-used fields

• RXR-1 Route is the field every receiver reads — it is required, and it drives clinical interpretation, alerts, and the FHIR route element. Common values come from HL7 table 0162 (e.g. PO oral, IM intramuscular, IV intravenous, SC subcutaneous).
• RXR-2 Administration Site names the body location and pairs with RXR-6 for laterality (left/right). For immunizations it captures where the vaccine was given.
• RXR-4 Administration Method distinguishes how the route is performed (e.g. injection vs IV push vs IV piggyback).

Version differences (2.3 to 2.8.2)

• 2.3/2.4: RXR-1 and RXR-2 present; coded fields used the CE data type.
• 2.5: RXR-6 Administration Site Modifier added; coded fields migrate from CE to CWE.
• 2.6+: the Administration Site value set is aligned to table 0550; older feeds may still send the legacy site table.
• Receivers built for earlier versions ignore the trailing fields they do not recognize.

Common mistakes

• Confusing RXR-1 Route with RXR-4 Method — route is the path into the body, method is how it is delivered along that route.
• Dropping a repeated RXR segment when an order specifies more than one route.
• Assuming RXR-2 site codes are UCUM or SNOMED — they are HL7 table values unless a coding system is supplied in the CWE.
• Treating RXR-1 as optional; it is the one required field and a missing route should be rejected.

Examples

Minimal valid RXR (only the required route):

RXR|PO^Oral^HL70162

Fully-populated RXR (intramuscular injection, left deltoid):

RXR|IM^Intramuscular^HL70162|LD^Left Deltoid^HL70550|SYR^Syringe^HL70164|IJ^Injection^HL70165||L^Left^HL70495

Annotated breakdown of the fully-populated example:

RXR                      ← segment ID
IM^Intramuscular^HL70162 ← RXR-1  Route (required)
LD^Left Deltoid^HL70550  ← RXR-2  Administration Site
SYR^Syringe^HL70164      ← RXR-3  Administration Device
IJ^Injection^HL70165     ← RXR-4  Administration Method
                         ← RXR-5  Routing Instruction (empty)
L^Left^HL70495           ← RXR-6  Administration Site Modifier

In-context inside a pharmacy order (ORC + RXO + RXR):

MSH|^~&|CPOE|MERCYGEN|PHARM|MERCYGEN|20260610090000||OMP^O09^OMP_O09|MSG410|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
ORC|NW|PON5567^MERCYGEN||||||||20260610090000||1234^SMITH^JANE^A^^^MD
RXO|AMOXICILLIN 500MG CAP^^L|500||MG|CAP
RXR|PO^Oral^HL70162

In-context inside a VXU immunization (RXA + RXR):

MSH|^~&|EHR|MERCYGEN|IIS|STATE|20260610100000||VXU^V04^VXU_V04|MSG777|P|2.5.1
PID|1||MR12345^^^MERCYGEN^MR||DOE^JOHN^Q||19800101|M
ORC|RE|PON5601^MERCYGEN
RXA|0|1|20260610100000|20260610100000|140^Influenza^CVX|0.5|mL^^UCUM
RXR|IM^Intramuscular^HL70162|LD^Left Deltoid^HL70550

FHIR mapping

RXR maps to the administration detail of two resources: MedicationRequest.dosageInstruction for medication orders and Immunization for vaccine administration. Official ConceptMaps: RXR to MedicationRequest, RXR to Immunization.

MedicationRequest:

Immunization:

Fields without a published target: RXR-6 Administration Site Modifier has no mapping in either ConceptMap; on the Immunization map RXR-3, RXR-4, and RXR-5 are also unmapped (Immunization carries only route and site).

Engine considerations

• Required in practice: RXR-1 is required; reject or flag a route-less RXR.
• Preserve repeating RXR segments — an order may carry more than one route, and collapsing them loses clinical meaning.
• Read the coding system component of each CWE; do not assume a default table, since senders may use local or SNOMED codes for route, site, and method.
• Keep RXR-1 (route) and RXR-4 (method) distinct when mapping — they target different FHIR elements (route vs method).

How Vorro parses and produces RXR

Vorro decodes each RXR CWE field by its coding system, preserves repeated RXR segments as distinct routes, and validates RXR-1 against the configured route table. On the FHIR side Vorro emits dosageInstruction.route/site/method for medication orders and Immunization.route/site for vaccine messages, attaching the site modifier (RXR-6) as an extension where the target resource supports it.

Related pages

• RXO — the pharmacy/treatment order segment RXR accompanies.
• RXA — the administration segment RXR follows in immunization messages.
• ORM messages — order messages that carry RXR.

Sources

• HL7 v2-to-FHIR IG — segment maps index
• HL7 v2-to-FHIR IG — RXR to MedicationRequest ConceptMap
• HL7 v2-to-FHIR IG — RXR to Immunization ConceptMap
• HL7 Version 2.5.1 product brief

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