# CP.4.2.1 Medication Interaction and Allergy Checking (Function) - HL7 Electronic Health Record System Functional Model, Release 2.1.1 v2.1.1

## Requirements: CP.4.2.1 Medication Interaction and Allergy Checking (Function) 

 
Provide alerts for potential medication interactions and medication allergy reactions. 



## Resource Content

```json
{
  "resourceType" : "Requirements",
  "id" : "EHRSFMR2-CP.4.2.1",
  "meta" : {
    "profile" : [
      "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/FMFunction"
    ]
  },
  "language" : "en",
  "extension" : [
    {
      "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
      "valueCode" : "normative"
    },
    {
      "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
      "valueCode" : "ehr"
    }
  ],
  "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/Requirements/EHRSFMR2-CP.4.2.1",
  "version" : "2.1.1",
  "name" : "CP_4_2_1_Medication_Interaction_and_Allergy_Checking",
  "title" : "CP.4.2.1 Medication Interaction and Allergy Checking (Function)",
  "status" : "active",
  "date" : "2025-12-13T09:06:06+00:00",
  "publisher" : "HL7 International / Electronic Health Records",
  "contact" : [
    {
      "telecom" : [
        {
          "system" : "url",
          "value" : "http://www.hl7.org/Special/committees/ehr"
        }
      ]
    }
  ],
  "description" : "Provide alerts for potential medication interactions and medication allergy reactions.",
  "jurisdiction" : [
    {
      "coding" : [
        {
          "system" : "http://unstats.un.org/unsd/methods/m49/m49.htm",
          "code" : "001",
          "display" : "World"
        }
      ]
    }
  ],
  "purpose" : "Check and provide alerts at the time of medication order based upon coded, active and non-active medications for possible interactions, allergies, sensitivities, intolerances, and other adverse reactions.",
  "statement" : [
    {
      "extension" : [
        {
          "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/requirements-dependent",
          "valueBoolean" : false
        }
      ],
      "key" : "EHRSFMR2-CP.4.2.1-01",
      "label" : "CP.4.2.1#01",
      "conformance" : ["SHALL"],
      "conditionality" : false,
      "requirement" : "The system SHALL conform to function [CPS.4.2.1](Requirements-EHRSFMR2-CPS.4.2.1.html) (Support for Medication Interaction and Allergy Checking) to determine allergic reactions, drug-drug interactions, and other potential adverse reactions, and render alerts or notifications when new medications are ordered.",
      "derivedFrom" : "EHR-S_FM_R1.1 DC.1.7.1#16"
    },
    {
      "extension" : [
        {
          "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/requirements-dependent",
          "valueBoolean" : false
        }
      ],
      "key" : "EHRSFMR2-CP.4.2.1-02",
      "label" : "CP.4.2.1#02",
      "conformance" : ["SHALL"],
      "conditionality" : false,
      "requirement" : "The system SHALL conform to function [CP.1.2](Requirements-EHRSFMR2-CP.1.2.html) (Manage Allergy, Intolerance and Adverse Reaction List) to provide the ability to manage interaction and allergy checking and render alerts and notifications when new medications are ordered."
    },
    {
      "extension" : [
        {
          "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/requirements-dependent",
          "valueBoolean" : false
        }
      ],
      "key" : "EHRSFMR2-CP.4.2.1-03",
      "label" : "CP.4.2.1#03",
      "conformance" : ["MAY"],
      "conditionality" : false,
      "requirement" : "The system MAY provide the ability to render an alert, at the time a new medication is prescribed/ordered, that drug interaction, allergy, and formulary checking will not be performed against uncoded or free text medication(s)."
    },
    {
      "extension" : [
        {
          "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/requirements-dependent",
          "valueBoolean" : true
        }
      ],
      "key" : "EHRSFMR2-CP.4.2.1-04",
      "label" : "CP.4.2.1#04",
      "conformance" : ["MAY"],
      "conditionality" : false,
      "requirement" : "The system MAY provide the ability to render a notification, at the time a new uncoded medication is prescribed/ordered, that drug interaction, allergy, and formulary checking will not be performed, according to scope of practice, organizational policy, and/or jurisdictional law."
    },
    {
      "extension" : [
        {
          "url" : "http://hl7.org/ehrs/uv/ehrsfmr2/StructureDefinition/requirements-dependent",
          "valueBoolean" : true
        }
      ],
      "key" : "EHRSFMR2-CP.4.2.1-05",
      "label" : "CP.4.2.1#05",
      "conformance" : ["SHALL"],
      "conditionality" : false,
      "requirement" : "The system SHALL provide the ability to render and tag as inactive recently inactivated medications for inclusion in current medication screening according to scope of practice, organizational policy, and/or jurisdictional law."
    }
  ]
}

```
