Which scenario supports that a drug is a prodrug?

• A. Oral administration requires first-pass activation to become active; IV bypasses activation
• B. IV administration bypasses activation completely
• C. First-pass metabolism inactivates prodrugs
• D. Prodrugs cannot be activated in the liver

Answer: (A)

A prodrug is an inactive or less active form that is converted into the active drug by the body's metabolic processes. Many prodrugs rely on first-pass metabolism after oral administration, where enzymes in the liver (and sometimes the gut wall) transform the prodrug into the active compound. The described scenario fits this pattern: the oral dose must undergo first-pass activation to become active, whereas delivering the same compound intravenously bypasses that first-pass step and may prevent activation. This difference—activation occurring during first-pass after oral dosing—supports that the drug is a prodrug. If first-pass metabolism inactivated prodrugs, or if a drug could not be activated by liver enzymes, or if IV administration inherently activated the drug, those would not align with the prodrug concept.