Drugs in this catagory are substances that have a high abuse potential and are not acceptable for medical use in the United States. Included in this catagory are herion, LSD, and mescaline.

The medications in this schedule have a high abuse potential with severe psychic or phychic or physical dependence liability. Schedule II controlled subtances consist of certain narcotics, stimulants and depressants. Examples include hydromorphone (Dilaudid), hydrocodone combination products (as of October 6, 2014), meperidine (Demerol), methylphenidate (Ritalin), methadone, fentanyl, amphetamine, methamphetamine, morphine, pentobarbital, secobarbital, and oxycodone.

Medications in this schedule have an abuse potential less than those in Schedules I and II. Included are compounds containing limited quantities of certain narcotic and non-narcotic drugs. Their abuse may lead to moderate or low physical dependence or high psychological dependence. Examples of Schedule III substances include codeine (Tylenol with Codeine), butalbital, pentobarbital combination products, and dihydrotestosterone.

Substances in this catagory have an abuse potential less than those listed in Schedule III which may lead only to limited physical dependence or phychological dependence. Schedule IV medications include butorphanol (Stadol), chloral hydrate, diazepam, flurazepam, midazolam (Versed), pemoline (Cylert), phenobarbitol, sibutramine (Meridia), zaleplon (Sonata), zolpidem (Ambien), dextropropoxyphene dosage forms, and pentazocine (Talwin-NX).

These substances have an abuse potential less than those listed in Schedule IV and consist primarily of preparations containing limited quantities of certain narcotic and stimulant drugs generally used for antitussive, antidiarrheal and analgesic purposes.

A Federal list of Controlled Substances including the drug schedule can be found on the Drug Enforcement Administrations's website at justice.gov/dea/pubs/scheduling.html