WASHINGTON (AP) — A panel of government health advisers said Friday there's no clear evidence that a harder-to-crush version of the painkiller OxyContin designed to discourage abuse actually resulted in fewer overdoses or deaths.

The conclusion from the Food and Drug Administration advisory panel comes more than a decade after Purdue Pharma revamped its blockbuster opioid, which has long been blamed for sparking a surge in painkiller abuse beginning in the 1990s.

In a series of non-binding votes, the FDA experts said that the updated OxyContin appeared to cut down abuse via snorting and inject...