HL7 RXC Pharmacy/Treatment Component Order

HL7 field reference RXC fields from HL7 v2.5.1 Show fields

These are the generated fields for the version selected at the top of the page. The document stays the same, but the reference panel follows that version.

Fields

FieldNameRequiredRepeatableTypeTable
RXC.1 RX Component Type Yes No ID 0166
RXC.2 Component Code Yes No CE
RXC.3 Component Amount Yes No NM
RXC.4 Component Units Yes No CE
RXC.5 Component Strength No No NM
RXC.6 Component Strength Units No No CE
RXC.7 Supplementary Code No Yes CE
RXC.8 Component Drug Strength Volume No No NM
RXC.9 Component Drug Strength Volume Units No No CWE

RXC describes a component of a pharmacy or treatment order, useful for compound medications or mixed products.

The standard describes RXC this way: If the drug or treatment ordered with the RXO segment is a compound drug OR an IV solution, AND there is not a coded value for OBR-4-universal service ID, which specifies the components (base and all additives), then the components (the base and additives) are specified by two or more RXC segments. The policy of the pharmacy or treatment application on substitutions at the RXC level is identical to that for the RXO level.

Pharmacy/treatment segments split a medication workflow into ordered, encoded, dispensed, administered, component, route, timing, and instruction details.

Be very clear about whether a field describes what was ordered, what the pharmacy dispensed, what was scheduled to be given, or what was actually administered. Those are related, but they are not the same event.

The v2.5.1 structures show RXC in OMP_O09 - OMP - Pharmacy/treatment order, ORP_O10 - ORP - Pharmacy/treatment order acknowledgment, RAR_RAR - Pharmacy/treatment administration information, and RAS_O17 - RAS - Pharmacy/treatment administration, and 14 other message structures. That tells you where it can appear, but the implementation guide still decides which optional fields are meaningful.

For practical interface work, read the generated field panel for datatype, required, repeatable, and table details, then use the notes below to decide what the field should mean in the receiving workflow.

RXC-1 RX Component Type RequiredR SingleS TypeID Table0166

RXC-1 qualifies the pharmacy workflow rather than identifying it. This is the sort of field receivers often use for branching, filtering, or display grouping.

Use the agreed value set, starting from HL7 table 0166. A local code without an agreed coding system is a small ambiguity that becomes a mapping problem later.

RXC-2 Component Code RequiredR SingleS TypeCE

RXC-2 identifies the Component Code for this pharmacy workflow. Send the identifier that the receiving system actually keys on, and keep the assigning authority or coding system visible when the datatype supports it.

RXC-3 Component Amount RequiredR SingleS TypeNM

RXC-3 carries a measured, counted, priced, or dosed value. A number without the expected unit, currency, or companion qualifier is much easier to misread than an empty field.

RXC-4 Component Units RequiredR SingleS TypeCE

RXC-4 supplies the units that make the companion numeric field meaningful. Units should be coded consistently, especially for medication, lab, specimen, and billing quantities.

RXC-5 Component Strength OptionalO SingleS TypeNM

RXC-5 carries Component Strength for this pharmacy workflow. Populate it only when the receiver has a clear use for it, and keep the value in the datatype shape shown in the generated field panel.

RXC-6 Component Strength Units OptionalO SingleS TypeCE

RXC-6 supplies the units that make the companion numeric field meaningful. Units should be coded consistently, especially for medication, lab, specimen, and billing quantities.

RXC-7 Supplementary Code OptionalO RepeatableR TypeCE

RXC-7 identifies the Supplementary Code for this pharmacy workflow. Send the identifier that the receiving system actually keys on, and keep the assigning authority or coding system visible when the datatype supports it.

If there are several identifiers, use repetitions deliberately and make each repeat self-explanatory rather than relying on position alone.

RXC-8 Component Drug Strength Volume OptionalO SingleS TypeNM

RXC-8 carries a measured, counted, priced, or dosed value. A number without the expected unit, currency, or companion qualifier is much easier to misread than an empty field.

RXC-9 Component Drug Strength Volume Units OptionalO SingleS TypeCWE

RXC-9 supplies the units that make the companion numeric field meaningful. Units should be coded consistently, especially for medication, lab, specimen, and billing quantities.

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