<?xml version="1.0" encoding="UTF-8"?>

<Observation xmlns="http://hl7.org/fhir">
  <id value="TxImp03"/>
  <meta>
    <profile value="http://hl7.org/fhir/uv/genomics-reporting/StructureDefinition/therapeutic-implication"/>
  </meta>
  <text>
    <status value="generated"/><div xmlns="http://www.w3.org/1999/xhtml">Poor metabolizer of Citalopram</div>
  </text>
  <extension url="http://hl7.org/fhir/StructureDefinition/workflow-relatedArtifact">
    <valueRelatedArtifact>
      <type value="citation"/>
      <url value="https://cpicpgx.org/guidelines/guideline-for-selective-serotonin-reuptake-inhibitors-and-cyp2d6-and-cyp2c19/"/>
    </valueRelatedArtifact>
  </extension>
  <status value="final"/>
  <category>
    <coding>
      <system value="http://terminology.hl7.org/CodeSystem/observation-category"/>
      <code value="laboratory"/>
    </coding>
  </category>
  <category>
    <coding>
      <system value="http://terminology.hl7.org/CodeSystem/v2-0074"/>
      <code value="GE"/>
    </coding>
  </category>
  <code>
    <coding>
      <system value="http://hl7.org/fhir/uv/genomics-reporting/CodeSystem/tbd-codes-cs"/>
      <code value="therapeutic-implication"/>
    </coding>
  </code>
  <subject>
    <reference value="Patient/CGPatientExample01"/>
  </subject>
  <effectiveDateTime value="2019-04-01"/>
  <performer>
    <reference value="Organization/ExampleOrg"/>
  </performer>
  <derivedFrom>
    <reference value="Observation/Pgx-geno-1001"/>
  </derivedFrom>
  <component>
    <code>
      <coding>
        <system value="http://loinc.org"/>
        <code value="51963-7"/>
      </coding>
    </code>
    <valueCodeableConcept>
      <coding>
        <system value="http://www.nlm.nih.gov/research/umls/rxnorm"/>
        <code value="2556"/>
        <display value="citalopram"/>
      </coding>
    </valueCodeableConcept>
  </component>
  <component>
    <code>
      <coding>
        <system value="http://hl7.org/fhir/uv/genomics-reporting/CodeSystem/tbd-codes-cs"/>
        <code value="therapeutic-implication"/>
      </coding>
    </code>
    <valueCodeableConcept>
      <coding>
        <system value="http://loinc.org"/>
        <code value="LA9657-3"/>
        <display value="Poor metabolizer"/>
      </coding>
    </valueCodeableConcept>
  </component>
  <component>
    <code>
      <coding>
        <system value="http://hl7.org/fhir/uv/genomics-reporting/CodeSystem/tbd-codes-cs"/>
        <code value="conclusion-string"/>
      </coding>
    </code>
    <valueString value="For citalopram, a 50% reduction in starting dose is recommended with therapeutic drug monitoring to guide dose adjustment or select an alternate drug not predominantly metabolized by CYP2C19. Refer to current guidelines for dosage and recommendations at https://cpicpgx.org/guidelines/guideline-for-selective-serotonin-reuptake-inhibitors-and-cyp2d6-and-cyp2c19/. If CYP2D6 genotyping is available, refer to the current guidelines for dosing recommendations."/>
  </component>
</Observation>