Controlled Substances Scheduling and Regulation

Classification and Scheduling

• The Drug Enforcement Administration (DEA) determines scheduling for substances like Schedules II and III, based on judgments about the potential for their abuse, accepted medical use, and safety under medical supervision, as established by the Comprehensive Drug Abuse Prevention and Control Act of 1970 1
• Schedule II opioids include morphine, oxymorphone, oxycodone, and oxycodone combination products, as well as hydromorphone and fentanyl, which have high potential for abuse similar to other opioids 1
• Codeine (without combination products) is classified as Schedule II, and codeine combined with acetaminophen (APAP) is classified as Schedule III 1
• Schedule III opioids include combination products, such as hydrocodone (15 mg or less) combined with acetaminophen or ibuprofen, as well as some codeine combination products 1

Prescription Monitoring and Control Measures

• Prescription drug monitoring programs (PDMPs) track Schedule II through IV controlled substances to identify diversion and doctor shopping, with most states allowing healthcare providers and pharmacists to access PDMPs for patients under their care 2

Clinical Implications for Prescribing

• Equianalgesic doses of opioids are equally efficacious in relieving pain regardless of their DEA classification, and there is no reason to consider an equianalgesic dose of a short-acting Schedule II opioid more effective in providing pain relief than a short-acting Schedule III opioid 1, 3
• Long-acting or extended-release Schedule II products such as oxycodone ER, methadone, fentanyl patches, or morphine extended-release are indicated for chronic pain and should not be used for acute pain 1
• Long-acting and extended-release opioids are for use in opioid-tolerant patients only and are not intended for use as an "as-needed" analgesic 1

Rescheduling of Substances

• Cannabis has historically been classified as Schedule I, though recent recommendations suggest rescheduling to Schedule III based on findings that its abuse potential is less than Schedule I and II substances, it has currently accepted medical use, and may lead to moderate or low physical dependence 4, 5

Drug Scheduling Under the Controlled Substances Act

Introduction to Controlled Substances

• The United States Controlled Substances Act (CSA) classifies drugs into five schedules (I through V) based on their abuse potential, accepted medical use, and safety profile, with Schedule I representing substances with the highest abuse potential and no accepted medical use, and Schedule V representing the lowest potential for abuse 6

Schedule I Controlled Substances

• Heroin is the prototypical Schedule I opioid, distinguished from Schedule II opioids like morphine and oxycodone specifically because it lacks accepted medical use despite similar abuse potential 6
• The Department of Health and Human Services and Drug Enforcement Administration jointly determine that Schedule I classification requires both high abuse potential AND no currently accepted medical use 6

Prescribing and Monitoring Implications

• Prescription drug monitoring programs track Schedule II through IV (or II through V) controlled substances to identify diversion and doctor shopping, with forty-one states having operational programs 7
• Doctor shopping is defined variably as obtaining prescriptions from 2 or more prescribers within 30 days, greater than 4 during one year, or greater than 5 during one year 7
• NHS guidance mandates that prescribed medicines are dispensed with no more than 28 days' supply, with additional requirements applying specifically to Schedule 2 and 3 medicines under the Misuse of Drugs Act 8

Schedule II and III Controlled Substances

• Schedule II prescriptions require additional documentation under the Misuse of Drugs Act, with specific requirements for prescribing that specify total quantity, number of days, strength, dose, and frequency 8

Schedule IV Controlled Substances

• Benzodiazepine receptor agonists are uniformly classified as Schedule IV, including non-benzodiazepines: eszopiclone, zolpidem, zaleplon, and benzodiazepines: estazolam, temazepam, triazolam, flurazepam 9

Critical Prescribing Considerations

• Schedule II substances require the most stringent documentation including specification of total quantity, number of days, strength, dose, and frequency 8

Physician Assistant Schedule II Prescribing Authority

Regulatory Framework for Schedule II Substances

• Implementation of prescription drug monitoring programs (PDMPs) was associated with a 30% reduction in Schedule II opioid prescribing rates across 24 states, as reported by the American Medical Association 10
• The Centers for Disease Control and Prevention recommends checking the state PDMP before prescribing any Schedule II medication to identify potential diversion, doctor shopping, or concurrent prescriptions from multiple providers 10

Controlled Substances Schedules III, IV, and V

Schedule III Controlled Substances

• Schedule III substances have moderate to low potential for physical and psychological dependence, less than Schedule II but more than Schedule IV 11
• Hydrocodone combination products (≤15 mg hydrocodone) combined with acetaminophen or ibuprofen are classified as Schedule III 12, 11
• Buprenorphine products, a partial opioid agonist used for pain and opioid use disorder treatment, are classified as Schedule III 13
• Equianalgesic doses of Schedule III opioids provide equivalent pain relief to Schedule II opioids, with no inherent superiority of Schedule II agents 12, 11
• Schedule III opioids should not be used for chronic pain management in emergency department settings 12

Schedule IV Controlled Substances

• Schedule IV substances have low potential for abuse relative to Schedule III and limited risk of physical or psychological dependence 13
• Tramadol was reclassified to Schedule IV in 2014 by the FDA due to potential for abuse and dependence 13
• Phentermine-topiramate ER is classified as Schedule IV based on concerns for abuse and dependence 14

Prescription Monitoring Requirements

• All Schedule III and IV controlled substances are tracked by prescription drug monitoring programs (PDMPs) to identify diversion patterns, doctor shopping, and concurrent prescriptions from multiple providers, although specific details are not provided in the cited references 11

Critical Prescribing Caveats

• Long-acting or extended-release formulations of Schedule III opioids are contraindicated for acute pain and are intended only for opioid-tolerant patients with chronic pain 12, 11
• When prescribing Schedule III opioids on discharge, use the lowest practical dose for limited duration and assess patient's risk for misuse, abuse, or diversion 12
• Patients with history of substance use disorders require careful monitoring when receiving any Schedule IV medication 14
• Do not assume Schedule II opioids are more effective than Schedule III opioids at equianalgesic doses, as this is a misconception not supported by evidence 12, 11