A new class of pain relievers that targets musculoskeletal pain receptors, instead of more general pain pathways, could alleviate osteoarthritis pain better than any drug now on the market, but hurdles remain before it's approved by the U.S. Food and Drug Administration. Research on the new therapy was published yesterday in the New England Journal of Medicine.

Osteoarthritis occurs when joint cartilage wears down, with the worst cases requiring joint replacement surgery. The pain can be unrelenting, and there's no real cure. Patients often get through the day by relying on pain relievers, typically starting with over-the-counter options such as ibuprofen or acetaminophen, both nonsteroidal anti-inflammatory drugs (NSAIDs). As the pain intensifies and people become inured to the drugs' effects, they gradually work their way up to opioids such as oxycodone.