Drug Enforcement Agency
The Drug Enforcement Agency (DEA) oversees The Controlled Substances Act (CSA.) This act classifies drugs into five DEA schedules depending on level for abuse potential. They are commonly written using Roman numerals as seen below. For more information, visit the Drug Enforcement Administration website.
Schedule I drugs have a high potential for abuse and no currently accepted medical use in treatment in the United States. This is quite a controversial stance in the United States today as medical marijuana is becoming increasingly acceptable to the public as a suitable treatment for certain ailments.
Schedule II, also known as C2, drugs have a high potential for abuse as well, but are accepted as having a medical use unlike Schedule I drugs. These drugs are kept in their own locked area and have strict inventory policies. A pharmacy will keep an exact on-hand count on record. Examples are morphine and amphetamines.
Schedule III drugs have less potential for abuse than the drugs in Schedules I and II. Abuse of the drug may lead to moderate or low physical dependence or high psychological dependence. Certain steroids, like testosterone, fall into this schedule.
Schedule IV drugs have low potential for abuse relative to the drugs in Schedule 3. Abuse of the drug may lead to limited physical dependence or psychological dependence relative to the drugs in Schedule III. Common Schedule IV drugs are sleeping pills like Lunesta (eszopiclone) and Ambien (zolpidem).
Schedule V drugs The drug have a low potential for abuse relative to the drugs in Schedule IV. Abuse of the drug may lead to limited physical dependence or psychological dependence relative to the drugs in Schedule IV. An example is an anti-tussive (cough suppresant) that contains codeine like Robafen AC and Cheratussin AC.
Note: Some drugs may be considered a controlled-substance in certain states, but not on the federal list. Gabapentin is listed as a Schedule V in Tennessee, Michigan, and Kentucky.