<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A substance used to treat pain or cause sleep. Opiates are made from opium or have opium in them. Opiates bind to opioid receptors in the central nervous system. Examples of opiates are codeine, heroin, and morphine. An opiate is a type of analgesic agent.</n0:def-definition><n0:def-source>NCI-GLOSS</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Functionally related to the poppy (Papaver somniferum) alkaloid morphine, natural or synthetic Opiates have widespread effects in the central nervous system, and on smooth muscle, due to activation of specific delta, mu, and kappa opiate receptors (each controlling different brain functions). Opiates include natural ingredients of the poppy and their derivatives - opium, morphine, codeine, and heroin. Morphine preparations are used as analgesic, sedative, or anxiolytic agent, but are also abused as street drugs. (NCI04)</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>