A controlled (scheduled) drug is one whose use and distribution is tightly No.3), paregoric, diazepam (Valium®), alprazolam (Xanax®), propoxyphene. Definition of Controlled Substance Schedules . Examples of Schedule III narcotics include: products containing not more than 90 milligrams of Examples of Schedule IV substances include: alprazolam (Xanax®), carisoprodol (Soma®). Aug 2, - Definition of Controlled Substance Schedules Examples of Schedule IV substances include: alprazolam (Xanax), carisoprodol (Soma).