My son was a bellwether of a tragic kind.

On Nov. 6, 2012, as the opioid epidemic began to explode, Alex passed away in Philadelphia at the age of 25 of a heroin overdose. Only a few years before, during his freshman year at the University of Colorado at Boulder, this once popular and athletic young man whose jazz piano riffs were a source of beauty and wonder became addicted to OxyContin.

Like so many others, he’d switched to cheaper heroin when black-market prescription opioids became too expensive.

In the end, I blame Purdue Pharma, the maker of OxyContin, for Alex’s death — and for the deaths of tens of thousands of others who fell prey to Purdue’s fraudulent marketing schemes.

By now it is well-known that Purdue flooded the market with these dangerous drugs. What is less understood is that Purdue also worked hard to get unsuspecting patients on ever-higher doses for longer periods, all to boost profits. Purdue wasn’t alone in helping to unleash the epidemic. Other major drug companies, such as Johnson & Johnson, Cephalon, and Endo Health Solutions, heavily marketed opioids as well, and sometimes urged that patients remain on the drugs longer while downplaying the risks.

When researchers and federal regulators began to raise alarms about a rise in overdoses in the mid-2000s, physicians nationwide sharply reduced opioid prescriptions.

What was the response of Purdue Pharma? As prescription revenue dropped, drug reps pushed doctors to put more patients on ever more powerful opioids.

Investigators with the Massachusetts Attorney General’s Office found that Purdue, acting on internal studies showing that patients on higher doses remained on the drug longer, pressed its huge sales force to pressure doctors to put patients on the highest doses of OxyContin. As the company pushed ever more powerful opioids, more ended up on the black market, where naïve young people like my son obtained them.

In effect, Purdue created a market of addicted customers who had no choice but to consume their drugs in a perverse cycle of self-destruction.

“The major drug companies involved in creating the crisis of opioid addiction were not only aware of the possibility for addiction but intentionally exploited that risk to increase market share,” Claire Finkelstein, a University of Pennsylvania law professor who has studied the role of pharmaceutical companies in the opioid epidemic, told me.

Doctors were told that the higher doses would improve patients’ functioning and quality of life; they were not told that higher doses and longer length of treatment, though very profitable for Purdue, correlated with up to a 50-fold increase in the risk of overdose death.

Those remarkable findings, contained in Massachusetts Attorney General Maura Healey’s disturbing lawsuit against Purdue Pharma, go a long way toward explaining why Healey and more than 20 other state AGs have declined to sign on to a tentative multibillion-dollar settlement reached with Purdue in mid-September. Pennsylvania Attorney General Josh Shapiro filed a lawsuit the day after Purdue reached the settlement.

Healey and the other AGs are right. The epidemic unleashed in part by Purdue Pharma has caused incalculable suffering, and the settlement, which barely dents the $13 billion fortune of the company’s founding Sackler family, is an affront to tens of thousands who have become addicted and died, as well as their families.

For Purdue, the financial incentives of pushing higher-strength opioids were powerful. A 100-tablet bottle of 80-milligram OxyContin retailed for $1,500 as against $269 for Purdue’s lowest-strength, 10mg tablet, a fivefold jump in revenue.

That a health-care behemoth with sales of $35 billion would conduct its affairs more like a drug dealer than a responsible corporate citizen might seem shocking. But there is ample precedent in the conduct of tobacco companies, which peddled their wares for decades knowing but not acknowledging that nicotine was highly addictive, as much as heroin.

By now, the evidence that Purdue and other drugmakers underplayed the risk of prescription opioids to maximize their profits has become overwhelming. As a start, they must accept responsibility for the pain and the suffering that they’ve caused and give up far more of the profits they earned at the cost of tens of thousands of deaths.

Chris Mondics is a legal affairs journalist based in Philadelphia whose work has covered Capitol Hill, the health-care industry, the Supreme Court, and other topics.