LOS ANGELES – More times than she can count, Dr. Carin van Zyl has heard terminally ill patients beg to die. They tell her they can't handle the pain, that the nausea is unbearable and the anxiety overwhelming.

If she were in the same situation, she, too, would want life-ending medication, even though she doubts she would ever take it. "I would want an escape hatch," she said.

This fall, California became the fifth — and largest — state to allow physicians to prescribe lethal medications to certain patients who ask for it.

Yet van Zyl can't see herself as one of those doctors.

"This is my life's work, to relieve suffering," said van Zyl, head of palliative care medicine at Los Angeles County-USC Medical Center. To her, that does not mean cutting short a life.

"I can't imagine pulling the trigger," she said.

Weeks after California Gov. Jerry Brown signed the "end-of-life option act" into law, palliative care physicians like van Zyl are trying to come to terms with what it means for them and their terminally ill patients.

It's not just a question of whether they support aid-in-dying or personally would ever help end a life. Palliative care doctors say the law underscores the need to raise awareness among doctors and patients about what they do and to expand access to high-quality programs.

Contrary to some patients' fears, they say, palliative care doctors are not there to hasten death. Their job is to help seriously ill people get relief from symptoms and stress, and to improve quality of life for them and their families, regardless of how long the patients have to live.

The California law should be a "wake-up" call because it shows "how terrified patients are of what they will experience at the end of life," said Dr. R. Sean Morrison, professor of geriatrics and palliative care medicine at Mount Sinai's Icahn School of Medicine in New York.

Morrison said that once patients who want to hasten their death get their symptoms controlled and their spiritual needs addressed, the overwhelming majority want to keep living.

"Their choice shouldn't be an assisted death or living with intractable suffering," Morrison said. "That's what laws allowing assisted suicide, in the absence of palliative care, present as a choice to patients."

Palliative care has become more widespread in recent years, and more doctors, nurses and social workers are being trained in how to ­provide it.