1. Short title This Act may be cited as the Modernizing Drug Enforcement Act of 2018 . 2. Drugs or other substances that act as opioid mu receptor agonists (a) Definitions Paragraph (18) of section 102 of the Controlled Substances Act ( 21 U.S.C. 802 ) is amended to read as follows: (18) (A) The term opiate or opioid — (i) means any drug or other substance having an addiction-forming or addiction-sustaining liability similar to morphine or being capable of conversion into a drug having such addiction-forming or addiction-sustaining liability; and (ii) includes any drug or other substance that acts as an opioid mu receptor agonist. (B) The term opioid mu receptor is a molecule that when bound to, and activated by, an opioid mu receptor agonist would result in analgesia, euphoria, addiction, or respiratory depression in the central nervous system. (C) The term opioid mu receptor agonist is a substance that when bound to, and interacting with, the opioid mu receptor, activates the receptor to result in analgesia, euphoria, addiction, or respiratory depression. . (b) Scheduling Section 201 of the Controlled Substances Act ( 21 U.S.C. 811 ) is amended by adding at the end the following: (k) Opioid mu receptor agonists (1) In general Effective as of the date of enactment of the Modernizing Drug Enforcement Act of 2018 , schedule I under section 202 is deemed to include, unless specifically exempted or unless listed in another schedule, any chemical substances, including their salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible, that act as opioid mu receptor agonists, and any material, compound, mixture, or preparation that contains any quantity of such substances. (2) Exceptions A chemical substance is exempt from inclusion in schedule I by operation of paragraph (1) if the substance— (A) is the subject of an approved application submitted under subsection (b) or (j) of section 505 of the Federal Food, Drug, and Cosmetic Act