WASHINGTON (AP) — Federal health experts are taking a second look this week at the heart safety of pain medications used by millions of Americans to treat arthritis and other everyday aches and pains.

The Food and Drug Administration has started a two day meeting to examine the latest research on anti-inflammatory medicines called NSAIDS, which serve as the backbone of U.S. pain treatment.

The key question is whether naproxen — the key ingredient in Bayer’s Aleve and many other generic pain pills — carries a lower risk of heart attack and stroke than rival medications like ibuprofen, sold as Advil by Pfizer, among others.

Debate about whether one drug is safer than the others has waged for more than a decade without a clear answer.