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March 16, 2023
Medication-Assisted Treatment for Opioid Use Disorder
Opioids, such as heroin, fentanyl, and some prescription
reverse opioid overdose, but not used to treat opioid use
pain medications (including morphine and oxycodone), are
disorders.
substances that act on receptors in the brain important in
regulating pain and emotion. Opioids have high potential
Regulatory Framework
for misuse, dependence, and overdose. The label opioid use
Two overlapping systems of federal law apply to MAT for
disorder (OUD) is the diagnostic term for “a problematic
opioid use disorder: one regulating pharmaceuticals and the
pattern of opioid use leading to clinically significant
other regulating controlled substances.
impairment or distress,” as defined in the Diagnostic and
Statistical Manual of Mental Disorders (DSM-5-TR).
Federal Food, Drug, and Cosmetic Act (FFDCA)
Under the Federal Food, Drug, and Cosmetic Act (FFDCA,
Medication-Assisted Treatment (MAT)
21 U.S.C. §§301 et seq.), the Food and Drug
Medication-assisted treatment is the combined use of
Administration (FDA) in the Department of Health and
medication and other services (such as counseling) to treat
Human Services (HHS) has primary responsibility for
substance use disorders. Three medications are currently
ensuring the safety and effectiveness of pharmaceuticals,
used in MAT for opioid use disorder: methadone,
regardless of whether they are controlled substances. (For
buprenorphine, and naltrexone.
more information, see CRS Report R41983, How FDA
Approves Drugs and Regulates Their Safety and
Methadone and buprenorphine are both opioids; their use to
Effectiveness.) Methadone, buprenorphine, and naltrexone
treat opioid use disorder is often called opioid substitution
are subject to the FFDCA.
therapy, opioid replacement therapy, or opioid agonist
treatment. These medications can reduce the cravings and
Controlled Substances Act (CSA)
withdrawal symptoms that often accompany
Under the Controlled Substances Act (CSA, 21 U.S.C.
discontinuation of misused opioids, typically without
§§801 et seq.), the Drug Enforcement Administration
producing the same euphoria or “high” as the substances
(DEA) in the Department of Justice (DOJ) has primary
they replace. Research on MAT has found it to be the most
responsibility for regulating the use of controlled
effective treatment for OUD.
substances for legitimate medical, scientific, research, and
industrial purposes, and for preventing these substances
Methadone
from being diverted for illegal purposes. The CSA assigns
Methadone is a full opioid agonist, meaning it binds to and
various drugs and other substances to one of five schedules
activates opioid receptors in the brain. Methadone carries
based on accepted medical use, potential for misuse, and
risk of misuse but poses fewer risks of dependence and
severity of potential psychological or physical dependence.
overdose than some other full opioid agonists (e.g., heroin).
Schedule I contains substances that have no currently
Methadone suppresses withdrawal symptoms in
accepted medical use and are not available by prescription
detoxification therapy and controls the craving for opioids
(such as heroin). Schedules II, III, IV, and V include
in maintenance therapy.
substances that have recognized medical uses and are
progressively less dangerous and pose fewer risks. As
Buprenorphine
shown in Table 1, methadone, buprenorphine, and
Buprenorphine is a partial opioid agonist, meaning it binds
naltrexone are classified differently under the CSA. For
to opioid receptors in the brain and activates them, but not
more information, see CRS Report R45948, The Controlled
as much as full opioid agonists. Buprenorphine also carries
Substances Act (CSA): A Legal Overview for the 118th
risk of misuse but poses fewer risks of dependence and
Congress.
overdose than full opioid agonists. Like methadone,
buprenorphine is used for detoxification and maintenance
Table 1. FDA-Approved Medications for Opioid MAT
therapy.
Medication
Class
CSA Schedule
Naltrexone
Methadone
Ful Opioid Agonist
II
Naltrexone is an opioid antagonist, meaning it binds to
opioid receptors but does not activate them; it prevents
Buprenorphine Partial Opioid Agonist III
opioid agonists from binding to and activating opioid
Naltrexone
Opioid Antagonist
none
receptors. Naltrexone carries no known risk of misuse.
Naltrexone is used for relapse prevention because an
Source: Congressional Research Service, based on information
individual on naltrexone who uses opioids will not
publicly available from FDA and DEA.
experience the effects of those opioids. Naltrexone is
different from naloxone (e.g., Narcan), which is used to
Under the CSA, responsibility for regulating schedule II
medications used in MAT (i.e., methadone) falls to both
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Medication-Assisted Treatment for Opioid Use Disorder
DEA in DOJ and the Substance Abuse and Mental Health
who handles controlled substances. OTPs must also comply
Services Administration (SAMHSA) in HHS. The CSA
with relevant DEA regulations addressing records
requires most persons who handle controlled substances to
maintenance, security controls, and other matters. They
register with DEA. It further requires individuals treating
must also comply with any applicable state laws.
OUD with methadone to obtain a separate DEA registration
but leaves specific criteria for obtaining this registration up
COVID-19 OTP Flexibilities
to the executive agencies.
During the COVID-19 public health emergency (PHE),
SAMHSA and DEA allowed greater flexibilities for take-
Opioid Treatment Programs (OTPs)
home methadone. Beginning in March 2020 and throughout
The use of methadone to treat OUD is subject to federal
the duration of the PHE, SAMHSA has allowed states to
regulations beyond those that apply to the same medication
request a “blanket exception for all stable patients in an
used for other purposes (e.g., treating pain) or other
OTP to receive 28 days of take-home doses” or 14 days for
controlled substances. Both DEA and SAMHSA
patients who are less stable. SAMHSA is currently
promulgate rules for methadone treatment provided at
considering mechanisms to make this flexibility permanent
federally certified opioid treatment programs (known as
after the PHE expires.
narcotic treatment programs in DEA lexicon).
Requirements for OTPs are specified in the Code of
Office-Based Opioid Treatment
Federal Regulations (21 CFR Chapter II and 42 CFR Part
The use of buprenorphine and naltrexone outside of an OTP
8).
is often referred to as office-based opioid treatment
(OBOT) or office-based MAT (though it may occur in
According to these regulations, OTPs must obtain
various settings). Office-based opioid treatment is not
ï‚·
subject to the same regulations governing OTPs. The use of
accreditation from a SAMHSA-approved accreditor,
buprenorphine in OBOT is subject to CSA provisions
ï‚· certification from SAMHSA, and
regulating controlled substances in medical treatment or
ï‚·
telemedicine generally.
registration from DEA.
Prior to the December 2022 enactment of the Restoring
Programs meeting all requirements may “administer or
Hope for Mental Health and Well-Being Act (Division FF,
dispense directly (but not prescribe)” any drug approved by
Title I of P.L. 117-328, the Consolidated Appropriations
FDA for treatment of opioid use disorder. They may also
Act, 2023), practitioners meeting certain criteria were
administer a drug being studied for treatment of OUD, as
required to obtain a separate waiver via DEA and
authorized by FDA under an investigational new drug
SAMHSA (known as a DATA waiver or X waiver) in order
application.
to treat OUD with buprenorphine outside of an OTP.
Practitioners with DATA waivers were subject to limits on
With few exceptions, the use of methadone to treat OUD is
the number of patients they could treat at any time. P.L.
limited to OTPs, which may also offer other forms of MAT,
117-328 repealed the DATA waiver requirement and
including buprenorphine for detoxification or maintenance
patient limit. Thus, under current law, any practitioner
and naltrexone for relapse prevention. OTPs generally
registered with DEA to dispense (i.e., prescribe or
administer methadone on a daily basis, with staff observing
administer) controlled substances is authorized to use
as a patient takes an oral dose of liquid methadone. Stable
buprenorphine to treat OUD outside of an OTP, subject to
patients may be allowed to receive a few take-home doses
state laws.
(e.g., for a weekend or longer).
Naltrexone is not a controlled substance, and therefore its
OTP Accreditation
use is not governed by the CSA. Any practitioner with
Accreditation is based on a peer review process in which
prescribing authority (as determined by the state) can use
SAMHSA-approved accrediting organizations evaluate
naltrexone in the treatment of OUD.
OTPs by making site visits and reviewing policies,
procedures, and practices. Examples of accrediting
COVID-19 OBOT Telemedicine Flexibilities
organizations include The Joint Commission and the
Prior to the COVID-19 PHE, practitioners initiating patients
Commission on Accreditation of Rehabilitation Facilities.
with buprenorphine for OUD were required to conduct an
in-person medical evaluation (21 U.S.C. §829). During the
OTP Certification
COVID-19 PHE, SAMHSA and DEA allowed practitioners
Certification is based on SAMHSA’s determination that an
to prescribe buprenorphine via telemedicine without first
accredited program is qualified to carry out treatment
conducting such evaluation. In March 2023, DEA issued a
conforming to standards in federal regulation. SAMHSA
proposed rule that would permanently allow practitioners to
uses the results of the accreditation process as well as other
initiate patients with buprenorphine for OUD via
information to determine whether a program is qualified.
telemedicine without first conducting an in-person
SAMHSA promulgates guidelines to help accrediting
evaluation, provided such evaluation took place within 30
organizations and OTPs conform to treatment standards.
days (88 FR 12890).
OTP Registration
Registration with DEA as an OTP is separate from—and in
Johnathan H. Duff, Analyst in Health Policy
addition to—the DEA registration required of any “person”
IF12348
(including a hospital, pharmacy, or doctor, among others)
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Medication-Assisted Treatment for Opioid Use Disorder


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