Generally, a controlled substance is an illegal drug that can have a of the substances listed in the schedules of the Controlled Substances Act of (CSA). than Schedule III drugs, and include Xanax, Soma, Klonopin, Valium, Ativan. The Controlled Substances Act is the federal drug policy that regulates the Schedule 4: Examples of Schedule 4 drugs include Ambien, Xanax, and Valium. A Listing of drugs and their schedule are located at Controlled Substance Act Xanax, Soma, Darvon, Darvocet, Valium, Ativan, Talwin, Ambien, Tramadol.