Controlled Substance Schedules

Article Author:
Brian Kenny
Article Editor:
Patrick Zito
2/10/2019 9:23:57 AM
PubMed Link:
Controlled Substance Schedules


The United States Government developed the Federal Comprehensive Drug Abuse Prevention and Control Act (Controlled Substances Act) in 1970. One of the primary purposes of the act was to improve the development, distribution, and allocation of controlled medications. The Controlled Substances Act categorizes certain medications into five different schedules based on misuse potential. Schedule I medications have the highest misuse potential; schedule V medications have the lowest misuse potential.[1]

Issues of Concern

As many states have now passed laws that decriminalize marijuana, this does not change the federal decision of marijuana as a schedule I drug. There is a collaboration between the US Attorney General and the Department of Health and Human Services to determine the hierarchy of schedule for a medication.[1][2]

There has been a recent discussion on controlled substance policy, with the current state of the opioid epidemic in the United States. One implication to combat the overuse of opioids has been by the Centers of for Medicare and Medicaid Services (CMS), which uses an Over-utilization Monitoring System (OMS) which is part of the Medicare Part D, to help identify patients at risk for use disorder. Another initiative has been to implement national registries that would indicate controlled substance allocation by a patient search.[3][4]

Clinical Significance

Schedule I medications have very high misuse potential and are considered to have no FDA (Food and Drug Administration) approved medical use. These medications are prohibited from being prescribed or distributed. Examples of schedule I drugs are heroin, ecstasy, lysergic acid diethylamide (LSD), marijuana and gamma-hydroxybutyric acid.[1] 

Schedule II drugs have a high misuse potential with or without known dependence to develop, yet these medications have accepted clinician use. Examples of schedule II drugs are cocaine, morphine, codeine, hydromorphone, methadone, fentanyl.[1]

Schedule III pharmaceuticals are considered to have an intermediate level of misuse potential. Drugs in this classification include anabolic steroids and ketamine.[1]

Schedule IV medications are considered to have some misuse potential but are less of a risk than schedule III drugs. Examples of such are clonazepam, diazepam, midazolam, phenobarbital, and tramadol.[1]

Schedule V drugs have the lowest potential for misuse and development of use disorder; examples of such are pregabalin, diphenoxylate/atropine, and promethazine.[1]

Only registered practitioners with the Drug Enforcement Agency (DEA) are permitted to prescribe controlled substances. All prescriptions for schedule II medications must be given to the pharmacist in a written form or transmitted by an approved computer system for EPCS (electronic prescribing of controlled substances). In fact, a number of states now require EPCS systems be used for controlled substance prescribing. A prescription for a schedule II medication may be called in by a registered practitioner in an emergency situation; however, a written prescription must follow up within 7 days.[5]


[1] Gabay M, The federal controlled substances act: schedules and pharmacy registration. Hospital pharmacy. 2013 Jun;     [PubMed PMID: 24421507]
[2] Controlled Substances Quotas. Final rule. Federal register. 2018 Jul 16     [PubMed PMID: 30020581]
[3] Larrat EP,Marcoux RM,Vogenberg FR, Implications of recent controlled substance policy initiatives. P     [PubMed PMID: 24669180]
[4] Coleman JJ, The supply chain of medicinal controlled substances: addressing the Achilles heel of drug diversion. Journal of pain & palliative care pharmacotherapy. 2012 Sep     [PubMed PMID: 22973912]
[5] Gabay M, Federal controlled substances act: controlled substances prescriptions. Hospital pharmacy. 2013 Sep;     [PubMed PMID: 24421533]