The Durham-Humphrey Amendment of 1951 established the fundamental distinction between which two categories of drugs?

• A. Provided bases for prescription and non-prescription drugs
• B. Created DESI program
• C. Expanded FDA authority over OTC labeling
• D. Required efficacy testing for all drugs

Answer: (A)

The key idea here is the formal split the amendment created between drugs that require a clinician’s prescription and those that can be bought without one. It established two categories: prescription drugs (Rx), which must be dispensed only with a prescription and often under professional supervision, and non-prescription drugs (OTC), which are considered safe enough for consumer use with proper labeling. The change also clarified dispensing by pharmacists—oral prescriptions and refills could be handled under the prescriber’s authorization, with labeling that reflects the drug’s status. This landmark reform does not address drug efficacy testing (that came later) or the DESI program; its main purpose was to define and regulate the Rx versus OTC distinction and the associated labeling and dispensing practices.