The FDA has been overseeing drugs in the US since the beginning of the 20th century. In 1970 the FDA released the following drug classifications, or drug schedules, under the Controlled Substance Act (CSA). The drug classification schedules organize drugs into groups based on risk of abuse or harm. Those drug categories with high risk and no counterbalancing benefit are banned from medical practice and are Schedule I drugs.
Definition of Controlled Substance Schedules
Drugs and other substances that are considered controlled substances under the Controlled Substances Act (CSA) are divided into five schedules. An updated and complete list of the schedules is published annually in Title 21 Code of Federal Regulations (C.F.R.) §§ 1308.11 through 1308.15. Substances are placed in their respective schedules based on whether they have a currently accepted medical use in treatment in the United States, their relative abuse potential, and likelihood of causing dependence when abused. Some examples of the drugs in each schedule are listed below.
Schedule I Controlled Substances
Substances in this schedule have no currently accepted medical use in the United States, a lack of accepted safety for use under medical supervision, and a high potential for abuse.
Some examples of substances listed in Schedule I are: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), peyote, methaqualone, and 3,4-methylenedioxymethamphetamine (“Ecstasy”).
Schedule II/IIN Controlled Substances (2/2N)
Substances in this schedule have a high potential for abuse which may lead to severe psychological or physical dependence.
Examples of Schedule II narcotics include: hydromorphone (Dilaudid), methadone (Dolophine), meperidine (Demerol), oxycodone (OxyContin, Percocet), and fentanyl (Sublimaze, Duragesic). Other Schedule II narcotics include: morphine, opium, and codeine.
Examples of Schedule IIN stimulants include: amphetamine (Dexedrine, Adderall), methamphetamine (Desoxyn), and methylphenidate (Ritalin).
Other Schedule II substances include: amobarbital, glutethimide, and pentobarbital.
Schedule III/IIIN Controlled Substances (3/3N)
Substances in this schedule have a potential for abuse less than substances in Schedules I or II and abuse may lead to moderate or low physical dependence or high psychological dependence.
Examples of Schedule III narcotics include: combination products containing less than 15 milligrams of hydrocodone per dosage unit (Vicodin), products containing not more than 90 milligrams of codeine per dosage unit (Tylenol with Codeine), and buprenorphine (Suboxone).
Examples of Schedule IIIN non-narcotics include: benzphetamine (Didrex), phendimetrazine, ketamine, and anabolic steroids such as Depo-Testosterone.
Schedule IV Controlled Substances
Substances in this schedule have a low potential for abuse relative to substances in Schedule III.
Examples of Schedule IV substances include: alprazolam (Xanax), carisoprodol (Soma), clonazepam (Klonopin), clorazepate (Tranxene), diazepam (Valium), lorazepam (Ativan), midazolam (Versed), temazepam (Restoril), and triazolam (Halcion).
Schedule V Controlled Substances
Substances in this schedule have a low potential for abuse relative to substances listed in Schedule IV and consist primarily of preparations containing limited quantities of certain narcotics.
Examples of Schedule V substances include: cough preparations containing not more than 200 milligrams of codeine per 100 milliliters or per 100 grams (Robitussin AC, Phenergan with Codeine), and ezogabine.