Attorney General Maura Healey, along with attorneys general from 38 other states, is seeking information from five opioid manufacturers and three distributors as they expand an investigation into the origins of the addiction crisis that has claimed thousands of lives.

At an announcement Tuesday in Boston, Healey said the attorneys general are looking into whether manufacturers misrepresented the dangers of prescription painkillers.

“What did they know and when did they know it?’’ Healey asked. “Did they know how addictive these drugs were when they sold them? Did they mislead patients . . . ignore information that could have saved lives?’’

The majority of people who became addicted to opioids started with prescribed medications, which became widely available as doctors answered calls to better treat pain and received assurances that opioid painkillers were safe.

Healey said the investigation was expanding since June, when it was first announced, and for the first time revealed the names of the companies that are receiving subpoenas.

Drugmakers Purdue Pharma, Endo, Janssen, Teva Pharmaceutical Industries, and Allergan; and distributors AmerisourceBergen, Cardinal Health, and McKesson are all receiving subpoenas

The attorneys general want to find out whether the three distributors, which together manage about 90 percent of US opioid distribution, properly tracked and reported suspicious orders.

The Healthcare Distribution Alliance, which represents the companies that link pharmaceutical manufacturers with pharmacies, hospitals, and clinics, said in a statement that distributors are not responsible for the volume of opioid prescribing.

“Distributors have no ability to influence what prescriptions are written,’’ said CEO John M. Gray.

But Gray said the alliance would like to help address “this public health crisis and its root causes.’’

At the announcement, Healey was surrounded by advocates and public officials who took turns decrying the toll of opioid addiction, which claimed 2,000 lives in Massachusetts last year.

They welcomed the investigation by Healey and others.

“This gives hope to families and friends who have lost loved ones,’’ said Joanne Peterson, executive director of Learn to Cope, a support network for families dealing with addiction.

Middlesex County District Attorney Marian Ryan described attending the funeral this past weekend of “a bright, promising, well-educated, happy, engaged 24-year-old. . . . You cannot help but ask, ‘Why did this happen? How did this happen?’ . . . That is what today is about.’’

Dozens of local and state governments have already filed, announced, or publicly considered lawsuits against drugmakers or distributors, according to the Associated Press.

In 2007, Purdue Pharma, maker of OxyContin, agreed to pay $600 million after pleading guilty to federal charges that it misled regulators, doctors, and patients about the drug’s risk of addiction and abuse.

The company had told doctors that OxyContin was less likely to be misused because of its time-release formulation, but people soon learned that chewing or crushing and injecting the drug would produce a powerful high.

Felice J. Freyer can be reached at felice.freyer@globe.com. Follow her on Twitter @felicejfreyer.