Which medication is used for treating arthritis?

Naproxen is the correct choice for treating arthritis, as it is a nonsteroidal anti-inflammatory drug (NSAID) that helps reduce pain, swelling, and inflammation associated with various types of arthritis, including osteoarthritis and rheumatoid arthritis. Its mechanism of action involves inhibiting certain enzymes that contribute to the inflammatory process, making it effective for patients experiencing arthritis symptoms.

Other options listed do not serve this purpose. Quinidine is primarily used to treat certain types of irregular heartbeat and has no role in arthritis treatment. Valium (diazepam) is a benzodiazepine used primarily for anxiety disorders, muscle spasms, and seizures, lacking any direct application in managing arthritis. Lorazepam, also a benzodiazepine, serves similar functions related to anxiety and sedation and is not indicated for arthritis. This distinction makes naproxen the appropriate choice for managing arthritis pain and inflammation.