What is MedicationKnowledge?

MedicationKnowledge is a reference resource containing information about medications — essentially a medication catalog. It is used for:

• Medication formulary management
• Dosing guidelines
• Cost information
• Interaction data (stored on the resource itself)

Common Use Cases

1. Formulary lookup — check whether a medication is on a plan’s formulary.
2. Dosing guidelines — retrieve pediatric vs adult dosing rules.
3. Cost comparison — compare generic vs brand-name costs.
4. Interaction data — read interaction information recorded on the MedicationKnowledge resource itself.

Searching MedicationKnowledge

# Look up a medication by code
curl "https://api.esus.health/fhir/MedicationKnowledge?code=197361" \
  -H "Authorization: Bearer YOUR_TOKEN"

The search returns a Bundle of matching MedicationKnowledge resources.

Reading Interaction Data

Interactions are stored on the MedicationKnowledge resource in the interaction[] array. To read the interactions for a known medication, GET the resource by id:

curl "https://api.esus.health/fhir/MedicationKnowledge/c1a2e3d4-5b6f-7890-abcd-ef1234567890" \
  -H "Authorization: Bearer YOUR_TOKEN"

Example response fragment:

{
  "resourceType": "MedicationKnowledge",
  "id": "c1a2e3d4-5b6f-7890-abcd-ef1234567890",
  "code": { "coding": [{ "code": "11289", "display": "Warfarin" }] },
  "interaction": [{
    "interactant": [{
      "itemReference": {
        "reference": "MedicationKnowledge/aa11bb22-cc33-dd44-ee55-ff6677889900"
      }
    }],
    "severity": "high",
    "description": "Warfarin + NSAIDs increases bleeding risk"
  }]
}

Severity Levels

Monograph and Related Information

Monograph, cost, administration guidelines, and drug characteristics are stored directly on the MedicationKnowledge resource. Read them by GETting the resource by id.

Note: A dedicated cross-resource interaction-check operation is planned but not exposed as an endpoint today. For current interaction checks, read the interaction[] array on each MedicationKnowledge and compose the check at the client layer.