Amobarbital, Secobarbital, and Pentobarbital when combined with non-controlled drugs or in suppository form are classified as Schedule III.

• A. Schedule II
• B. Schedule IV
• C. Schedule III
• D. Not scheduled

Answer: (C)

The main concept is that the scheduling of a drug depends not only on the drug itself but also on its formulation or combination. Amobarbital, secobarbital, and pentobarbital are potent barbiturates with high abuse potential, so when they’re sold as single-ingredient products they’re placed in Schedule II. If they’re combined with a non-controlled drug or prepared in a suppository form, regulators downgrade the product to Schedule III because the presence of a non-controlled component or the specific dosage form reduces the potential for abuse relative to the pure drug, while still allowing legitimate medical use. In practice, this means a barbiturate product in these presentations is treated as Schedule III, reflecting the lower abuse risk compared to the pure, standalone barbiturate forms.