The terms of a $4.85 billion settlement with pharmaceutical company Merck & Co Inc. present an interesting twist for Texas plaintiffs lawyers: If any of a lawyer’s clients decide to participate in the settlement, the lawyer must recommend the settlement to all of his clients.

On Friday, Merck announced it has agreed to pay the money to settle Vioxx-related claims in cases where the claimant suffered a heart attack, sudden cardiac death or ischemic stroke.