Former users of withdrawn painkiller Vioxx will be eligible for a piece of manufacturer Merck & Co.'s $4.85 billion nationwide settlement if they meet strict criteria meant to weed out people with bogus claims. They must:

-- Have had a claim filed by Thursday, the day before the deal was announced.

-- Already have medical documentation that they suffered a heart attack or an ischemic stroke; people who had mini-strokes or hemorrhagic strokes are not eligible.

-- Have proof they received at least 30 Vioxx pills.

-- Have received Vioxx pills recently enough to indicate they likely took the painkiller within two weeks of their injury.

-- Be legal U.S. residents alleging their injury occurred in the United States.

-- Promptly register their claims after being contacted by their current attorney.