Chicago filed a federal lawsuit Tuesday accusing the top three distributors of opioids of "placing profits over public health" and fueling a public health crisis blamed on "rampant over-prescribing and abuse" of pharmaceutical opioids.

Four years ago, Chicago blazed a legal trial with a lawsuit accusing leading opioid manufacturers of knowingly misrepresenting the benefits of opioids, concealing serious addiction risks and targeting the elderly and veterans by making bogus medical claims.

Two years later, Mayor Rahm Emanuel announced an agreement that called for Pfizer, Inc. to adhere to strict standards for the marketing and promotion of prescription opioids.

On Tuesday, the mayor escalated the city's ongoing legal battle in response to the burgeoning drug epidemic.

The city filed a lawsuit in U.S. District Court, targeting AmerisourceBergen Drug Corporation, Cardinal Health Inc. and McKesson Corporation for what City Hall claimed was their "unfettered and unlawful distribution of opioids" in Chicago. The three companies could not be reached for comment.

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