Representing Prescriptions and Medication Orders | Medplum

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Prescriptions and medication orders are very common in healthcare settings and accuracy is vitally important. This guide will go over how to represent all aspects of a medication order, from the request to the administration instructions. Note that this is an operational counterpart to the Modeling A Formulary documentation.

The MedicationRequest Resource [​](/content/docs/medications/representing-prescriptions-and-medication-orders#the-medicationrequest-resource "Direct link to the-medicationrequest-resource"/index.html)

Medication prescriptions should be represented in FHIR using the MedicationRequest resource. In addition, it can contain contextual information such as instructions on administration of the medication.

Detailed Medication Information [​](/content/docs/medications/representing-prescriptions-and-medication-orders#detailed-medication-information "Direct link to Detailed Medication Information"/index.html)

It is important to note that a MedicationRequest resource does not have detailed information on the drug that is being prescribed or ordered. Instead, this information will be in the related MedicationKnowledge resource with the same code. This code should be stored in the medicationCodeableConcept field of the MedicationRequest, establishing a link between the request and the details of the drug.

The MedicationKnowledge resource represents a type of medication that can be ordered. It contains details such as:

• Relationship to other medications
• Physical characteristics of the drug (color, imprint, etc.)
• Physical form of the drug (pill, powder, etc.)
• Description of the medication package (bottle, blister pack, etc.)
• Method of ingestion (oral, intravenous, etc.)

For more details on the MedicationKnowledge resource and how to model medications, see the Modeling a Formulary docs.

Representing Patient Instructions [​](/content/docs/medications/representing-prescriptions-and-medication-orders#representing-patient-instructions "Direct link to Representing Patient Instructions"/index.html)

The instructions for how the patient should take the medication should be included on the MedicationRequest.dosageInstruction field. This element includes fields to explain how, how often, and when the medication should be taken and is represented with a Dosage type.

Note that this field is stored as an array, so there can be multiple dosage instructions for each order. For example, the same medication may be taken multiple times throughout the day, but in different dosages each time. This is where the dosageInstruction.sequence field should be used to indicate which order the instructions are in.

Example: Dosage Instructions

{
  resourceType: 'MedicationRequest',
  status: 'active',
  intent: 'order',
  subject: {
    reference: 'Patient/homer-simpson',
  },
  medicationCodeableConcept: {
    coding: [
      {
        system: 'http://www.nlm.nih.gov/research/umls/rxnorm',
        code: '224917',
        display: 'Ritalin',
      },
    ],
  },
  dosageInstruction: [
    {
      sequence: 1,
      patientInstruction: 'Take one tablet orally with water, each morning',
      asNeededBoolean: false,
      route: {
        coding: [
          {
            system: 'http://snomed.info/sct',
            code: '26643006',
            display: 'Oral route',
          },
        ],
      },
      method: {
        coding: [
          {
            system: 'http://snomed.info/sct',
            code: '738995006',
            display: 'Swallow',
          },
        ],
      },
      doseAndRate: [
        {
          doseQuantity: {
            value: 1,
            unit: 'tablet',
          },
        },
      ],
      maxDosePerPeriod: {
        numerator: {
          value: 1,
          unit: 'tablet',
        },
        denominator: {
          value: 1,
          unit: 'day',
        },
      },
      maxDosePerAdministration: {
        value: 1,
        unit: 'tablet',
      },
    },
  ],
};

Distinguishing Between Prescriptions and Medication Orders [​](/content/docs/medications/representing-prescriptions-and-medication-orders#distinguishing-between-prescriptions-and-medication-orders "Direct link to Distinguishing Between Prescriptions and Medication Orders"/index.html)

A MedicationRequest can represent both a prescription and a medication fulfillment order. A prescription is an order for medication in an outpatient context, while a medication fulfillment order represents medication that will be administered in an inpatient context.

These types of requests should be differentiated as outpatient vs. inpatient using the MedicationRequest.category field, which represents the type of medical request. The FHIR MedicationRequest Admin Location value set can be used for this. Note that the category field is an array, so it is possible to have multiple values if you wish to categorize your requests in other ways as well.

Example: A MedicationRequest categorized for a prescription

{
  resourceType: 'MedicationRequest',
  // ...
  category: [
    {
      coding: [
        {
          system: 'https://www.hl7.org/fhir/valueset-medicationrequest-admin-location.html',
          code: 'outpatient',
        },
      ],
    },
  ],
};

Example: A MedicationRequest categorized for a medication fulfillment order

{
  resourceType: 'MedicationRequest',
  // ...
  category: [
    {
      coding: [
        {
          system: 'https://www.hl7.org/fhir/valueset-medicationrequest-admin-location.html',
          code: 'inpatient',
        },
      ],
    },
  ],
};

Representing Dispense Instructions and Fulfillment [​](/content/docs/medications/representing-prescriptions-and-medication-orders#representing-dispense-instructions-and-fulfillment "Direct link to Representing Dispense Instructions and Fulfillment"/index.html)

The instructions to the pharmacy on how the order should be dispensed should be included on the MedicationRequest.dispenseRequest field.

Example: Dispense Instructions

{
  resourceType: 'MedicationRequest',
  status: 'active',
  intent: 'order',
  subject: {
    reference: 'Patient/homer-simpson',
  },
  authoredOn: '2023-09-04',
  medicationCodeableConcept: {
    coding: [
      {
        system: 'http://www.nlm.nih.gov/research/umls/rxnorm',
        code: '1049221',
        display: 'acetaminophen 325 MG / oxycodone hydrochloride 5 MG Oral Tablet [Percocet]',
      },
    ],
  },
  requester: {
    reference: 'Practitioner/dr-alice-smith',
  },
  dispenseRequest: {
    initialFill: {
      quantity: {
        value: 30,
        unit: 'tablets',
      },
    },
    dispenseInterval: {
      value: 30,
      unit: 'days',
    },
    validityPeriod: {
      start: '2023-09-04',
      end: '2023-11-04',
    },
    numberOfRepeatsAllowed: 1,
    quantity: {
      value: 30,
      unit: 'tablets',
    },
    expectedSupplyDuration: {
      value: 30,
      unit: 'days',
    },
  },
};

Representing Dispense Fulfillments [​](/content/docs/medications/representing-prescriptions-and-medication-orders#representing-dispense-fulfillments "Direct link to Representing Dispense Fulfillments"/index.html)

The information related to fulfillment of a MedicationRequest should be stored on the MedicationDispense resource. If a MedicationRequest is refilled, there should be one MedicationDispense resource associated with the initial fill, and a MedicationDispense associated per each refill.

Preferred Pharmacies

There is currently no community consensus on how to store a patient's preferred pharmacy in FHIR, but Medplum suggests one of two options:

1. Add the information to a CareTeam resource associated with the Patient.
2. Use a FHIR Extension to model a preferred pharmacy. The Patient Preferred Pharmacy offers a way to do this.

• The MedicationRequest Resource
  • Detailed Medication Information
• Representing Patient Instructions
• Distinguishing Between Prescriptions and Medication Orders
• Representing Dispense Instructions and Fulfillment
  • Representing Dispense Fulfillments