Rhode Island MPJE Practice Exam 2026 – Complete Study Guide

The correct answer reflects the established regulation regarding the maximum amount of diphenoxylate allowed in a prescription formulation classified as a Schedule V controlled substance. In the context of the Controlled Substances Act and as specified in state regulations, diphenoxylate is often combined with atropine to discourage misuse.

When it comes to Schedule V formulations, the limit is set to ensure that the medication remains available for legitimate medical use while minimizing the potential for abuse. The limit of 2.5 mg per dosage unit provides a balance where the drug retains its therapeutic effects for treating diarrhea—for which it is typically prescribed—while adhering to legal restrictions designed to safeguard against misuse.

This standard is essential for pharmacy practice and understanding how certain substances are regulated, particularly how those in less restricted schedules can still have guidelines governing their use. The numbers for the other amounts, whether higher or lower, do not align with the legal standards set for Schedule V compounds containing diphenoxylate, thus reinforcing why 2.5 mg is the correct figure.