RDS^O13 — Pharmacy/Treatment Dispense Message

The hospital pharmacist confirms the effective dispensation of a drug: quantity, lot, container, date. RDS sends the info back to the HIS and the patient chart.

Purpose

RDS closes the prescription → pharmacy dispense cycle. It is emitted by the inpatient pharmacy after preparation and delivery of a dose to the ward. Carried data:

• quantity actually served (may differ from prescribed quantity);
• manufacturer lot number — traceability, recall management;
• expiry date;
• container identifier (bag, syringe, blister);
• identity of the preparer and verifying pharmacist (RXD-10, RXD-15).

Next step in the circuit is RAS^O17 (Pharmacy Administration), emitted by the nurse after administration to the patient.

Segment structure

RDS_O13
  MSH                    Message Header (mandatory)
  [ SFT ]                Software Segment (optional)
  [ NTE ]                Notes and Comments (optional)
  {                      Patient loop (1..n)
    [ PID ]              Patient Identification
    [ PD1 ]              Patient Additional Demographics
    [ { NTE } ]          Notes (repeatable)
    [ { AL1 } ]          Allergy (repeatable)
    [ PV1 ]              Patient Visit
    [ PV2 ]              Patient Visit - Additional Info
    {                    Order loop (1..n)
      ORC                Common Order
      [ RXE ]            Pharmacy/Treatment Encoded Order
      [ { NTE } ]        Notes (repeatable)
      {                  Dispense loop (1..n)
        RXD              Pharmacy/Treatment Dispense
        [ { RXR } ]      Pharmacy Route (repeatable)
        [ { RXC } ]      Pharmacy Component (repeatable)
        [ { NTE } ]      Notes (repeatable)
        [ { OBX } ]      Observation (repeatable)
      }
    }
  }

ORC — RXE

• ORC-1: RE (Result; the dispense is a result of the order).
• ORC-2: original prescription number (Placer Order Number).
• ORC-3: dispense number (Filler Order Number) — internal pharma key.
• RXE: echoes the original prescription. Identical to the RXE in the ORM/OMP.

RXD — Dispense

• RXD-1: dispense number (sequence).
• RXD-2: code of the drug served (SNOMED CT, CIP, UCD…).
• RXD-3: dispense date/time.
• RXD-4: quantity served.
• RXD-5: unit (MG, MCG, IU…).
• RXD-7: manufacturer lot number.
• RXD-8: expiry date.
• RXD-15: preparer identifier.

RXR — Pharmacy Route

• RXR-1: route of administration (table 0162: PO by mouth, IV intravenous, IM intramuscular…).

Real-world example

Dispense of 100 mg of aspirin, lot LOT2026-A0123, on 16 May 2026 at 08:45:

MSH|^~\&|PHARM|HOSP01|EHR|HOSP01|20260516084500||RDS^O13^RDS_O13|MSG00016001|P|2.5.1|||AL|NE
PID|1||MRN567890^^^HOSP^MR||DOE^JOHN^A^^MR.||19720515|M|||100 MAIN ST^^ANYTOWN^CA^90210^USA||(555)555-1234|||S||ACCT123456
PV1|1|I|MED^205^B^HOSP01|EM|||DRSMITH^Smith^James^A^^DR.|||CAR|||1|||DRSMITH^Smith^James^A^^DR.|ADM
ORC|RE|ORD-2026-04501||DISP-2026-09001|CM|||||20260516084500
RXE|^Q6H&0600&0001^^20260516060000^20260518060000^R|385055000^Aspirin 100mg tab^SNOMED|100|||MG|TAB^Tablet^HL70162|||DRSMITH^Smith^James^A^^DR.|1
RXD|1|385055000^Aspirin 100mg tab^SNOMED|20260516084500|100|MG|TAB^Tablet^HL70162|LOT2026-A0123|20271231|PHARM-DISP01||100|MG|0||TS^TS^L^Robert^Robert^^^^||4
RXR|PO^Oral^HL70162
OBX|1|NM|3141-9^Quantity dispensed^LN||100|MG|0-1000|N|||F

Acknowledgment (ACK)

MSH|^~\&|EHR|HOSP01|PHARM|HOSP01|20260516084501||ACK^O13^ACK|ACK00016001|P|2.5.1
MSA|AA|MSG00016001

Common errors

• Missing RXD-7 (lot): makes traceability impossible during a manufacturer recall.
• RXD-4 ≠ prescribed RXE-1 quantity: must be documented (often via OBX comment), else dose-check alerts trigger.
• Missing expiry date (RXD-8): opens the door to dispensing expired products.
• Wrong ORC-2: breaks the link to the originating prescription.

FHIR equivalent

In FHIR R5, the equivalent is MedicationDispense: quantity served, container, lot, date — same model in JSON / REST.

See also: ORM^O01, RAS^O17, and RGV^O15.