The three largest US drug distributors and a major generic-drug manufacturer have agreed to pay more than $250m (€225m) to settle the first federal trial over the companies’ role in fuelling the US opioid epidemic.

Johnson & Johnson (J&J) has offered to pay $4bn (€3.6bn) to settle all claims accusing the company of helping fuel the US opioid epidemic, as part of a potentially larger deal involving drugmakers and distributors that could top $20bn.