Diphenoxyate is classified as which Schedule?

• A. Schedule I
• B. Schedule II
• C. Schedule III
• D. Schedule IV

Answer: (B)

Understanding how drugs are scheduled helps explain why diphenoxylate with atropine fits a lower schedule. Scheduling is based on a drug’s accepted medical use and its potential for abuse and dependence. Diphenoxylate itself acts mainly as an opioid to slow intestinal movement, but its central effects are limited, especially when paired with atropine to discourage misuse. This combination has medical use and has a relatively low potential for abuse compared with higher-scheduled drugs, so it is placed in the lowest schedule that still recognizes medical usefulness.

That’s why the classification is Schedule V. It isn’t placed in higher schedules because those require a higher abuse potential and more stringent control; it isn’t Schedule I because those are substances with no accepted medical use.