These doctors' 298 patients who died of overdoses ranged in age from 21 to 79. The median age was 48.

Many had histories of mental illness or addiction, including previous overdoses or stints in drug treatment. Others did not start out as high-risk patients. They were middle-aged adults — teachers, nurses and police officers — with bad backs, injured knees and other non-life-threatening conditions.

Lynn Blunt was a 46-year-old mother of four who suffered from degenerative disc disease. Despite the pain, she was careful not to exceed the recommended dosage of her medications, said her husband, Lonnie. She wanted to remain alert enough to care for her two youngest children, girls ages 14 and 11, he said.

The condition eventually crippled Blunt, leaving her dependent on a cane and unable to continue working as a U.S. customs inspector. She saw a series of doctors, eventually ending up at Vu's California Pain Center.

According to coroner's records, Vu prescribed skin patches containing fentanyl, a pain reliever 100 times more powerful than morphine.

On Sept. 7, 2006, coroner's records show, Blunt went to Vu's clinic to receive an epidural injection of an unspecified medication for her pain. A day later, she was found dead in her family's apartment in Downey.

Blunt overdosed on multiple drugs prescribed by Vu and two other doctors, coroner's records show. High levels of fentanyl were found in her system.

Blunt had been looking forward to a planned trip to the East Coast to visit one of her two grown children, her husband said.

"We followed the prescriptions," he said. "Something didn't mix well."

Vu, a native of Vietnam, was 11 when he and his family immigrated to the U.S. as refugees just before the fall of Saigon in 1975. They settled in Seattle.

As a high school student, he volunteered at a clinic for low-income families and was impressed, he said, by the selflessness of physicians serving "people who really needed help."

He earned undergraduate and medical degrees from the University of Washington and served a residency in anesthesiology at USC. He is board-certified in that field and in pain medicine.

"I pretty much achieved the dream come true that America affords," said Vu, 49, who lives with his wife and four children on Christiana Bay in Huntington Beach.

Vu said most of his patients are referred by other doctors, who turn to him as "a last resort" for those who have been battling pain for years. Many patients come to him already dependent on narcotics, he said.

Vu said he conducts routine urine tests to make sure they take their medications as prescribed and do not use illegal drugs. He said he regularly uses a state-run prescription monitoring program to see whether any of his patients are also obtaining drugs from other doctors.

"I am doing the best I can in this very difficult field," he said. "I consider myself to be one of the best. But we have limits."

He said any patient death from an overdose was unacceptable, but added that he has treated thousands of patients successfully with the same drugs.

"Are we willing to trade that?" he asked. "Are we willing to withhold pain medications from everyone?"

Vu said he was unaware of many of his patients' deaths until Times reporters contacted him. He called the information "eye-opening."

"I'm a physician," Vu said. "I feel terrible when somebody loses their life. I'm the one who should be prolonging life, so I'm saddened by that."