Controlled Substances Deep Dive
The regulation of controlled substances is one of the most important and most tested topics on the CPHT exam. This guide covers the Controlled Substances Act, DEA requirements, prescription handling, and diversion prevention in detail.
The Controlled Substances Act (CSA)
The CSA, enacted in 1970, is the federal law that regulates the manufacture, distribution, and dispensing of controlled substances. It established the five-schedule classification system based on:
- The drug's potential for abuse
- Whether the drug has a currently accepted medical use in the United States
- The degree of physical or psychological dependence the drug may cause
Schedule Details
Schedule I (C-I)
These substances have a high potential for abuse, no currently accepted medical use in the United States, and a lack of accepted safety for use under medical supervision. They are not available by prescription in standard pharmacy practice.
Examples: Heroin, LSD, psilocybin, MDMA (ecstasy), mescaline
Schedule II (C-II)
High abuse potential with currently accepted medical use. Abuse may lead to severe physical or psychological dependence.
Examples:
- Opioids: oxycodone, hydrocodone (single-entity), morphine, fentanyl, methadone, hydromorphone, meperidine
- Stimulants: amphetamine, dextroamphetamine, methylphenidate, lisdexamfetamine
- Other: cocaine (limited medical use as topical anesthetic), pentobarbital
Schedule III (C-III)
Abuse potential less than C-I and C-II. Currently accepted medical use. Abuse may lead to moderate or low physical dependence or high psychological dependence.
Examples: Testosterone, other anabolic steroids, buprenorphine, ketamine, products containing less than 15 mg of hydrocodone per dosage unit combined with a non-controlled substance (these formulations were rescheduled to C-II in 2014)
Schedule IV (C-IV)
Lower abuse potential relative to C-III. Currently accepted medical use.
Examples: Alprazolam, diazepam, lorazepam, clonazepam, zolpidem, eszopiclone, tramadol, carisoprodol, phenobarbital
Schedule V (C-V)
Lowest abuse potential among controlled substances. Currently accepted medical use.
Examples: Pregabalin, lacosamide, cough preparations containing limited quantities of codeine (e.g., codeine-containing cough syrups in certain formulations)
DEA Registration
- Every entity that manufactures, distributes, or dispenses controlled substances must register with the DEA.
- Pharmacies use DEA Form 224 for initial registration and Form 224a for renewal.
- DEA registration must be renewed every 3 years.
- Each pharmacy location must have its own DEA registration number.
- The DEA number is tied to a specific address - if a pharmacy moves, a new registration is needed.
DEA Number Validation
A valid DEA number has two letters followed by seven digits. To verify:
- The first letter indicates registrant type: A, B, or F for physicians/pharmacies/distributors; M for mid-level practitioners.
- The second letter is the first letter of the registrant's last name.
- Add the 1st, 3rd, and 5th digits.
- Add the 2nd, 4th, and 6th digits and multiply by 2.
- Add both results. The last digit of the total must equal the 7th digit (check digit).
Prescribing Requirements
Schedule II
- Requires a written (signed) prescription, electronic prescription (EPCS), or oral prescription in an emergency.
- Emergency oral prescriptions must be followed by a written or electronic prescription within 7 days.
- Faxed prescriptions for C-II generally serve as advance notice; the original written prescription must be presented before dispensing. Exceptions include hospice patients, long-term care residents, and compounded IV/parenteral preparations.
- No refills are permitted.
- Multiple prescriptions for the same C-II drug may be issued on the same day with instructions to fill on different dates (up to a 90-day supply in some states), but each must be a separate prescription.
Schedules III-V
- May be prescribed by written, electronic, oral, or faxed prescription.
- Up to 5 refills within 6 months from the date the prescription was written.
- After 6 months or 5 refills (whichever comes first), a new prescription is required.
Partial Dispensing
- C-II: A partial fill may be dispensed if the pharmacy does not have enough stock. The remaining portion must be supplied within 72 hours. If it cannot be supplied within 72 hours, the prescriber must be notified and a new prescription is required for the remaining amount. Exception: patients in long-term care facilities or with terminal illness may receive partial fills over 60 days.
- C-III to C-V: Partial fills are permitted as long as the total quantity does not exceed the amount prescribed and all fills are completed within the 6-month window.
Transfer of Prescriptions
- C-II prescriptions may not be transferred.
- C-III through C-V prescriptions may be transferred one time between pharmacies, unless the pharmacies share a real-time online database (in which case, multiple transfers may be allowed).
- Both the transferring and receiving pharmacists must document the transfer with specific required information.
Ordering and Receiving
| Schedule | Ordering Method |
|---|---|
| C-II | DEA Form 222 (triplicate) or CSOS (Controlled Substance Ordering System - electronic) |
| C-III to C-V | Standard purchase order (no DEA Form 222 required) |
Recordkeeping Requirements
- All controlled substance records must be maintained for at least 2 years (federal minimum; state requirements may be longer).
- C-II records must be kept separately from all other records.
- C-III through C-V records must be readily retrievable (often marked with a red "C" or filed separately).
- A perpetual inventory for C-II drugs is recommended and often required by state law.
- An initial inventory must be taken when a pharmacy first opens or when a registrant first handles controlled substances.
- A biennial (every 2 years) inventory is required by federal law.
- C-II drugs require an exact count during inventory.
- C-III through C-V drugs may be estimated if the container holds 1000 or fewer units; containers with more than 1000 must be exact-counted.
Theft and Loss Reporting
- Any theft or significant loss of controlled substances must be reported to the DEA using DEA Form 106.
- The pharmacy should also notify local law enforcement.
- The discovery of any discrepancy during inventory should trigger an investigation.
Destruction and Disposal
- Controlled substances must be destroyed through a DEA-registered reverse distributor or a DEA-authorized destruction event.
- DEA Form 41 documents the destruction of controlled substances.
- Witnesses are typically required for on-site destruction.
- The DEA has authorized certain pharmacies as collection sites where patients can return unused controlled substances through take-back programs.
Corresponding Responsibility
The pharmacist has a "corresponding responsibility" (along with the prescriber) to ensure that a controlled substance prescription was issued for a legitimate medical purpose by a practitioner acting in the usual course of professional practice. Red flags include:
- Prescriptions from the same prescriber for the same combination of drugs (e.g., opioid + benzodiazepine + muscle relaxant)
- Patients traveling long distances to fill prescriptions
- Cash-only payments for expensive controlled substances
- Frequent early refill requests
- Multiple prescribers for the same patient
Pharmacy technicians should bring suspicious prescriptions to the pharmacist's attention.
Prescription Drug Monitoring Programs (PDMPs)
Most states operate PDMPs - electronic databases that track controlled substance dispensing. Pharmacists and prescribers can check the database to identify potential abuse or doctor-shopping. Many states require a PDMP check before dispensing certain controlled substances.
Exam Tips
- Know the refill rules cold: C-II = no refills; C-III through C-V = up to 5 refills in 6 months.
- DEA Form 222 is for ordering C-II; Form 106 is for theft/loss; Form 41 is for destruction.
- Practice DEA number validation calculations.
- Understand the difference between partial filling of C-II vs. C-III through C-V.
- Remember that state law may be stricter than federal law - when there is a conflict, follow the stricter standard.