British consumer goods group Reckitt Benckiser has agreed to pay up to $ 1.4bn to US authorities, resolving to be a former subsidiary marketed a drug used to treat addiction to pain killers.

It is the largest mortgage in the United States. Two million Americans are now suffering from opioid use and the outbreak of opioid overdoses.

What caused the opioid crisis?

Andrew Kolodny, co-director of opioid policy research at the Heller School of Social Policy and Management, said the crisis is not linked to pharmaceutical companies.

"The Center for Disease Control has made it very clear: the reason so many Americans are addicted to opioids is that the medical community started to prescribe very aggressively starting in the mid-90s. As prescribing went up, addiction and overdose deaths went straight up in parallel, "he said.

What penalties have been handed out so far?

Reckitt Benckiser's $ 1.4bn settlement is by far the biggest contributor to the opioid crisis. Indivior, the former Reckitt subsidiary, is accused of mis-selling Suboxone, not an opioid but a drug used to treat opioid addiction – and importantly, the US government is not claiming that it is responsible for the crisis.

Indivior shares rose on Thursday on Suboxone, but Citi analysts said it was difficult to value the stock.

A small number of cases have been settled so far. Insys, the maker of subsystems, a spray based on the very powerful opioid fentanyl, settled a case for $ 225m last month. Purdue Pharma, owned by certain members of the wealthy Sackler family, settled a case with Oklahoma for $ 270m earlier in the year. It therefore settled a larger case of $ 600m back in 2007, where three executives pleaded guilty to misleading and defrauding physicians by claiming that OxyContin was less addictive than it was. Distributors, who have prescriptive pills and doctors, so have been involved in settlements.

What court cases are coming?

Harry Nelson, managing partner at Nelson Hardiman and the author of The United States of Opioidssaid the opioid cases are at a "really critical juncture". In October, thousands of claims are filed, mainly from US cities and counties, against 22 opioid manufacturers, distributors and pharmacies.

"I think the pressure is rising on the pharmaceuticals to start to move settlements forward," he said.

Mark Chalos, lawyer at Lieff Cabraser who is working on opioid cases, said this is a "novel approach to a novel catastrophe". but there are some models.

Hunter Shkolnik, another lawyer on the cases, said the case makes it to court.

In Oklahoma, Johnson & Johnson is currently on trial for his role in the crisis – and Mr Shkolnik said the case was almost like a "trailer" for the movie that could come in October.

"What they are showing in Oklahoma, I would not even call it the tip of the iceberg. It is barely poking out of the water. When this trial opens, it will go on sale in awe, "he said.

J & J is contesting the charges and said in a statement: "Our actions in the marketing and promotion of these important prescription pain medications were appropriate and responsible" market for this class of medications ".

What could they be liable for?

Drug companies are pushing back on the claims, arguing their products were not significant in causing the crisis. Carl Tobias, a professor at Richmond Law School, said there is no clear line of responsibility. "Liability usually follows some kind of bad behavior, with a causal link."

If judges and juries find liability, companies could face penalties based on how much the crisis has cost, as the government has ended up with extra healthcare, law enforcement and social services bills. The White House's Council of Economic Advisers has estimated that in 2015, the opioid epidemic cost more than $ 500bn, including the loss of life.

Perhaps more likely, settlements or fines could be used for the rest of their lives. Opioid treatment can cost about $ 6,000 a year, according to the National Institute on Drug Abuse.

Positive penalties above and beyond costs are possible, but less likely.

Even if companies are convicted, many do not want to be able to afford to pay. Insys filed for Chapter 11 bankruptcy just days after settlement and Purdue Pharma has said it is considered bankruptcy.

Are executives facing jail time?

So far, only Insys executives have been found guilty of criminal charges. Due to be sentenced in the autumn, they are up to 20 years – but are appealing. Many believe the insys case is particularly egregious – but some see it as having prosecutors and the public want to hold individuals accountable.

Additional reporting by Donato Paolo Mancini in London