(CNN) Five of the many companies accused in thousands of federal and state lawsuits over the nation's opioid epidemic may settle for over $50 billion, according to a source familiar with the negotiations.

Three pharmaceutical distribution companies -- AmerisourceBergen, Cardinal Health, and McKesson Corporation -- are in negotiations to settle with over 2,000 state, local and Native American tribal governments over their alleged roles in the nationwide opioid crisis, according to the source.

The source told CNN Thursday that the companies are proposing to pay a combined $18 billion over 18 years, in addition to Johnson & Johnson, which is in talks to contribute another $4 billion to the settlement.

If an agreement is reached, the source said that the settlement would also involve Teva Pharmaceuticals contributing $15 billion in anti-addiction drugs, plus an additional $14 billion towards the distribution of those drugs. Teva is one of the biggest producers of generic drugs.

The timing of the negotiations is important, as jury selection in the multi-district litigation case began Wednesday in the Northern District of Ohio and the trial is set to begin next Monday.

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