<?xml version="1.0" encoding="UTF-8"?><CodeSystem xmlns="http://hl7.org/fhir"><id value="substance-interaction-type"/><meta><lastUpdated value="2026-06-23T16:20:19.822+00:00"/></meta><text><status value="generated"/><div xmlns="http://www.w3.org/1999/xhtml"><p class="res-header-id"><b>Generated Narrative: CodeSystem substance-interaction-type</b></p><a name="substance-interaction-type"> </a><a name="hcsubstance-interaction-type"> </a><p>This case-sensitive code system <code>http://hl7.org/fhir/substance-interaction-type</code> defines the following codes:</p><table class="codes"><tr><td style="white-space:nowrap"><b>Code</b></td><td><b>Display</b></td><td><b>Definition</b></td></tr><tr><td style="white-space:nowrap">binding<a name="substance-interaction-type-binding"> </a></td><td>Binding</td><td>The substance binds to its target.</td></tr><tr><td style="white-space:nowrap">inhibition<a name="substance-interaction-type-inhibition"> </a></td><td>Inhibition</td><td>The substance inhibits the activity of its target.</td></tr><tr><td style="white-space:nowrap">activation<a name="substance-interaction-type-activation"> </a></td><td>Activation</td><td>The substance activates its target.</td></tr><tr><td style="white-space:nowrap">agonist<a name="substance-interaction-type-agonist"> </a></td><td>Agonist</td><td>The substance acts as an agonist of its target.</td></tr><tr><td style="white-space:nowrap">antagonist<a name="substance-interaction-type-antagonist"> </a></td><td>Antagonist</td><td>The substance acts as an antagonist of its target.</td></tr><tr><td style="white-space:nowrap">substrate<a name="substance-interaction-type-substrate"> </a></td><td>Substrate</td><td>The substance is a substrate of its target.</td></tr><tr><td style="white-space:nowrap">allosteric-modulator<a name="substance-interaction-type-allosteric-modulator"> </a></td><td>Allosteric modulator</td><td>The substance acts as an allosteric modulator of its target.</td></tr></table></div></text><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg"><valueCode value="brr"/></extension><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status"><valueCode value="informative"/></extension><extension url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm"><valueInteger value="1"/></extension><url value="http://hl7.org/fhir/substance-interaction-type"/><version value="6.0.0-ballot4"/><name value="SubstanceInteractionTypeExample"/><title value="Substance Interaction Type"/><status value="active"/><experimental value="true"/><date value="2026-06-23"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="The kind of interaction between a substance and its target, e.g. binding, inhibition, agonism."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/substance-interaction-type"/><content value="complete"/><concept><code value="binding"/><display value="Binding"/><definition value="The substance binds to its target."/></concept><concept><code value="inhibition"/><display value="Inhibition"/><definition value="The substance inhibits the activity of its target."/></concept><concept><code value="activation"/><display value="Activation"/><definition value="The substance activates its target."/></concept><concept><code value="agonist"/><display value="Agonist"/><definition value="The substance acts as an agonist of its target."/></concept><concept><code value="antagonist"/><display value="Antagonist"/><definition value="The substance acts as an antagonist of its target."/></concept><concept><code value="substrate"/><display value="Substrate"/><definition value="The substance is a substrate of its target."/></concept><concept><code value="allosteric-modulator"/><display value="Allosteric modulator"/><definition value="The substance acts as an allosteric modulator of its target."/></concept></CodeSystem>