NHS Digital FHIR Medicines (Retired - 2.1.14)

Prescribing (VMP, AMP and VTM)

Different prescribing practices and recording between primary and secondary care

Differences between secondary and primary care prescribing practices mean that there are differences in the way that medication is recorded in primary and secondary care. In hospital, a prescriber will record a medication for the nursing team to administer to the patient. This will usually be the generic name, plus dose, quantity, route and frequency. The nurse administering the medication will use this information to select the correct quantity of an actual product to give to the patient. In primary care, prescriptions are created by selecting a single medicinal product, with the rest of the prescription expressed in terms of that product.

Primary care medication records are product based:

• virtual medicinal product (VMP) - eg amoxicillin 500mg capsule
• actual medicinal product (AMP) – eg amoxil 500mg capsules (Dowelhurst Ltd).

The VMP code for amoxicillin 500mg capsule includes the active ingredient (amoxicillin), the strength (500 mg) and the form (capsule).

The following information is included in the structure of the medication record:

– dosage instructions (eg one, three times daily)

• quantity (eg 15 capsules)
• duration (eg five days).

Hospital prescribing records are dose based (and may also be product based):

• Virtual therapeutic moiety (VTM) – eg amoxicillin

The following information is included in the structure of the medication record:

• medication form (eg capsule)
• dose (eg 500mg)
• route (eg oral)
• medication frequency (eg one, three times daily).

VMP

The Virtual Medicinal Product (VMP) describes the generic title for a product including the form and strength.

"medicationCodeableConcept": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "323510009",
                "display": "Amoxicillin 500mg capsules"
            }
        ]
    },

AMP

The Actual Medicinal Product (AMP) describes an actual product which is known to have been available linked to the name of a particular supplier.

"medicationCodeableConcept": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "10460611000001105",
                "display": "Amoxil 500mg capsules (Dowelhurst Ltd)"
            }
        ]
    },

VTM Example

This is for illustrative purposes and should not be used, see section on form below for more details.

"medicationCodeableConcept": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "27658006",
                "display": "Amoxicillin"
            }
        ]
    },

Relationships

The relationships between VTM, VMP and AMP are:

• a VTM may be linked to one or more VMPs
• a VMP may be linked to one or more AMPs.

In terms of SNOMED CT, relationships between VTM, VMP and AMP can be described as:

• amoxil 500mg capsules (Dowelhurst Ltd) (AMP) is a amoxicillin 500mg capsule (VMP)
• amoxicillin 500mg capsule (VMP) is a oral form amoxicillin which is a amoxicillin (VTM).

Form

The dose, quantity and duration details are contained within the FHIR MedicationRequest resource. Form is not and this presents problems with VTM medications. For VTM prescriptions the use of FHIR Medication resource is highly recommended to express the form of the medication.

In the example below the VTM Amoxicillin is represented as a FHIR Medication

{
    "resourceType": "Medication",
    "id": "vtm-amoxicillin",
    "code": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "27658006",
                "display": "Amoxicillin"
            }
        ]
    },
    "form": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "385049006",
                "display": "Capsule"
            }
        ]
    }
}

When a medication needs to be represented using a FHIR Medication, the FHIR MedicationRequest resource MUST use a medicationReference instead of a medicationCodeableConcept to the Medication resource

E.g.

"medicationReference": {
        "reference":  "Medication/vtm-amoxicillin",
        "display": "Amoxicillin Capsule"
    }

or a reference within a FHIR Bundle

"medicationReference": {
        "reference":  "urn:uuid:495df5c5-5931-4795-960d-d2188bec3c2e",
        "display": "Amoxicillin Capsule"
    }

It is recommend to make use of display to hold the medication name and also the form. The use of contained resources to hold the Medication resource is discouraged (and is not suported by Electronic Prescription Service).

Dispensing (AMPP and VMPP)

Dispensing records should be pack based (Actual Medicinal Product Pack - AMPP) but product codes (VMP, AMP or VMPP) are permissible as defined within the “Guidance for Endorsement” (Ref: NPFIT-ETP-EIM-0015).

AMPP

The Actual Medicinal Product Pack (AMPP) describes an actual product which is known to have been available linked to both the name of a particular supplier and information on the pack size of the product.

"medicationCodeableConcept": {
        "coding":  [
            {
                "system": "http://snomed.info/sct",
                "code": "10460811000001109",
                "display": "Amoxil 500mg capsules (Dowelhurst Ltd) 12 capsule"
            }
        ]
    },

VMPP

The Virtual Medicinal Product Pack (VMPP) describes the generic title for a generic or proprietary product pack which is known to have been available. The description includes the pack size.

"medicationCodeableConcept": {
    "coding":  [
        {
            "system": "http://snomed.info/sct",
            "code": "5334111000001101",
            "display": "Amoxicillin 500mg capsules 12 capsule"
        }
    ]
}

Relationships

The relationships between AMPP and VMPP are:

• a VMP may be linked to one or more VMPPs
• a AMP may be linked to one or more AMPPs.
• a VMPP may be linked to one or more AMPPs

In terms of SNOMED CT, relationships between VTM, VMP and AMP can be described as:

• Amoxil 500mg capsules (Dowelhurst Ltd) 12 capsule (AMPP) is a amoxil 500mg capsules (Dowelhurst Ltd) (AMP)
• Amoxicillin 500mg capsules 12 capsule (VMPP) is a amoxicillin 500mg capsule (VMP).
• Amoxil 500mg capsules (Dowelhurst Ltd) 12 capsule (AMPP) is a Amoxicillin 500mg capsules 12 capsule (VMPP)