NORMAN, Okla. — Oklahoma's chief medical examiner shared tragic details about the opioid-related deaths of about three dozen residents during testimony in the state's lawsuit alleging drug manufacturer Johnson & Johnson and some of its subsidiaries contributed to the epidemic.

Dr. Eric Pfeifer testified Tuesday that the tragic narratives represent only a small portion of the autopsies his office has performed in recent years as overdose deaths skyrocketed. Attorney General Mike Hunter, who filed the case in 2017, has said curbing and ending the opioid epidemic in Oklahoma could cost billions of dollars.

Pfeifer said opioid overdose can traumatize a person's body in multiple ways.

"There's a triad of things including cerebral edema, which means a swollen brain, pulmonary edema, which means water in the lungs, and a distended bladder full of urine," he said. "That's pretty typical of opioid deaths."

Pfeifer read from a narrative prepared by his office involving a 28-year-old mother with a history of back pain who had just been placed on fentanyl patches and was found dead on her daughter's birthday.

Pfeifer also read accounts of the deaths of a 53-year-old woman found sitting up at her dining room table and a 55-year-old woman found by her husband in a bathtub overflowing with water.

The lawsuit alleges drugmakers marketed highly addictive opioids in a way that overstated their effectiveness and underplayed the risk of addiction. Johnson & Johnson has denied wrongdoing.

Oklahoma is one of about three dozen states that have filed lawsuits in state courts aiming to have local juries or judges decide the outcome. Oklahoma's is the first to go to trial.

Two companies, OxyContin-maker Purdue Pharma and Teva Pharmaceuticals , settled with Oklahoma ahead of the trial.