This drug is a ketone prodrug resembling Naproxen in structure and is converted into an acetic acid derivative in the body. It is the only non-acid NSAID in current use.

• A. Nabumetone
• B. Ketorolac
• C. Ketoprofen
• D. Etodolac

Answer: (A)

Non-acid prodrugs of NSAIDs are designed so the parent molecule itself isn’t an acid, reducing direct gastric irritation, and then it’s activated in the body to the active NSAID. Nabumetone fits this pattern: it is a ketone-containing molecule that structurally resembles naproxen but isn’t acidic on its own. After absorption, nabumetone is metabolized in the liver to naproxen, which is the active anti-inflammatory agent and a propionic acid derivative. That activation gives the same NSAID effect as naproxen but starts from a non-acid compound, helping to improve gastric tolerability. The other options are all acidic NSAIDs with inherent carboxylic acid groups (or different acid moieties) and do not function as non-acid prodrugs, so nabumetone is the best choice.