MedicationRequest — Medication prescription

The medication prescription in FHIR. Covers outpatient e-prescriptions, hospital orders, named prescriptions, and refills.

Purpose

MedicationRequest represents an order, request or recommendation for medication for a patient. The FHIR counterpart of OrderMessage for medications. Covers:

• outpatient e-prescriptions sent to a pharmacist;
• inpatient orders dispensed by the hospital pharmacy;
• named individual prescriptions;
• refills for chronic treatments;
• clinical decision support recommendations (intent plan, proposal).

For the actual dispense event, see MedicationDispense. For observed administration, see MedicationAdministration (hospital). For the patient's known regimen without an identifiable prescription, see MedicationStatement.

Key fields

dosageInstruction

Central sub-element that structures dosage. Main fields:

• text — human-readable free-text ("1 capsule 3 times daily for 7 days").
• timing.repeat.frequency + timing.repeat.period + timing.repeat.periodUnit — frequency.
• timing.repeat.boundsDuration or boundsPeriod — total duration.
• route — route of administration (SNOMED CT).
• method — method (slow infusion, sublingual…).
• doseAndRate[].doseQuantity or doseRange — unit dose.
• doseAndRate[].rateQuantity — flow rate (infusions).
• maxDosePerPeriod — maximum dose per period.
• asNeededFor — PRN medication with indication.

JSON example

Amoxicillin 500 mg PO, 3×/day, 7 days, indication otitis media:

{
  "resourceType": "MedicationRequest",
  "id": "example",
  "status": "active",
  "intent": "order",
  "category": [{
    "coding": [{
      "system": "http://terminology.hl7.org/CodeSystem/medicationrequest-admin-location",
      "code": "inpatient",
      "display": "Inpatient"
    }]
  }],
  "priority": "routine",
  "medication": {
    "concept": {
      "coding": [{
        "system": "http://www.nlm.nih.gov/research/umls/rxnorm",
        "code": "197361",
        "display": "Amoxicillin 500 MG Oral Capsule"
      }, {
        "system": "http://snomed.info/sct",
        "code": "323510009",
        "display": "Amoxicillin 500mg capsule"
      }],
      "text": "Amoxicillin 500 mg oral capsule"
    }
  },
  "subject": { "reference": "Patient/example" },
  "encounter": { "reference": "Encounter/example" },
  "authoredOn": "2026-05-14T11:00:00+01:00",
  "requester": { "reference": "Practitioner/example" },
  "reason": [{
    "concept": {
      "coding": [{
        "system": "http://snomed.info/sct",
        "code": "65363002",
        "display": "Otitis media"
      }]
    }
  }],
  "dosageInstruction": [{
    "sequence": 1,
    "text": "1 capsule by mouth, 3 times daily, for 7 days.",
    "timing": {
      "repeat": {
        "frequency": 3,
        "period": 1,
        "periodUnit": "d",
        "boundsDuration": { "value": 7, "unit": "d", "system": "http://unitsofmeasure.org", "code": "d" }
      }
    },
    "route": {
      "coding": [{
        "system": "http://snomed.info/sct",
        "code": "26643006",
        "display": "Oral route"
      }]
    },
    "doseAndRate": [{
      "type": {
        "coding": [{
          "system": "http://terminology.hl7.org/CodeSystem/dose-rate-type",
          "code": "ordered",
          "display": "Ordered"
        }]
      },
      "doseQuantity": {
        "value": 1,
        "unit": "capsule",
        "system": "http://unitsofmeasure.org",
        "code": "{capsule}"
      }
    }]
  }],
  "dispenseRequest": {
    "validityPeriod": {
      "start": "2026-05-14",
      "end": "2026-05-21"
    },
    "numberOfRepeatsAllowed": 0,
    "quantity": {
      "value": 21,
      "unit": "capsule",
      "system": "http://unitsofmeasure.org",
      "code": "{capsule}"
    }
  },
  "substitution": {
    "allowedBoolean": true
  }
}

• medication dual-coded — RxNorm 197361 + SNOMED 323510009.
• dosageInstruction with structured timing: 3 times per 1 day, bounds 7 days.
• route = oral (SNOMED 26643006).
• dispenseRequest.quantity = 21 capsules — consistent with 3 × 7.
• substitution.allowedBoolean = true — generic substitution allowed.

REST API

• GET /MedicationRequest/example — direct fetch.
• GET /MedicationRequest?patient=example&status=active — active treatments.
• GET /MedicationRequest?patient=example&authoredon=ge2026-01-01 — recent prescriptions.
• GET /MedicationRequest?patient=example&medication.code=http://www.nlm.nih.gov/research/umls/rxnorm|197361 — history of amoxicillin.
• $lookup on an RxNorm code to retrieve drug details.

Profiles

Common pitfalls

• status=active + intent=plan: inconsistent. A plan is not an active prescription. For execution, intent=order.
• medication.concept without RxNorm/ATC coding: free-text-only prescriptions are not interoperable. Always code.
• dispenseRequest.quantity ≠ dosageInstruction × duration: an order of 3 tab/day for 7 days but 50 tablets dispensed is suspicious (and illegal in several jurisdictions).
• Mixing doseQuantity and doseRange: only one at a time per doseAndRate.
• Refill without priorPrescription: breaks chronic treatment traceability.
• Malformed UCUM: mg is valid UCUM, milligram is not. {capsule} (with braces) for enumerable units.

Related resources

• Patient — subject.
• Encounter — context.
• Practitioner — prescriber.
• Medication — drug detail (form, composition, manufacturer).
• MedicationDispense — pharmacy dispense.
• MedicationAdministration — observed administration (hospital).
• MedicationStatement — known regimen (anamnesis).
• Condition — referenced via reason (indication).
• HL7 v2 equivalent — ORM^O01 segments RXO / RXE / RXR.