Worcester has joined a growing number of cities and states suing drug companies over the opioid crisis.

The city filed a lawsuit in Worcester Superior Court Monday with the goal of holding opioid drug manufacturers accountable for the "substantial damages the city has suffered, and will continue to suffer as it deals with the opioid epidemic."

The complaint alleges that prescription opioids are a gateway drug to heroin, based on data that approximately 80 percent of heroin users got hooked on the drug after taking prescription opioids.

"The drug companies placed profits above the health and well-being of their customers and communities in using unethical and unlawful methods to market and distribute opioids," the city said in a news release. "Their improper practices in turn created a population addicted to opioids, who then turned to heroin available on the black market."

Worcester said it will add up how much the opioid epidemic has cost the city, including increased first responder costs, Narcan acquisition and training, employee health insurance claims and costs, and the creation of addiction programs.

"We've tirelessly undertaken outreach initiatives designed to combat the opioid crisis created by the defendants' unlawful conduct," City Manager Edward M. Augustus said in a statement. "The City is seeking damages, not just to be reimbursed for its expenses, but also to halt the unlawful practices and find a way to end the opioid-heroin connection that has cost so many lives and created so much hardship."

The eight opioid manufacturers listed in the lawsuit are Purdue Pharma, Janssen, Endo, Actavis, Mallinckrodt, Teva, Collegium and Insys.

The city has hired Scott+Scott Attorneys at Law LLP and said it will not pay any of the costs of the lawsuit. Expenses and attorneys' fees will be paid only out of any amounts awarded to the city through the litigation.