OLYMPIA, Wash. (AP) -- Washington has become the second state in America to approve a medically assisted suicide law, following neighboring Oregon in allowing terminally ill people to obtain lethal prescription drugs from a doctor.

Supporters saw the victory as a bellwether for the larger movement to enact similar laws around the country.

"No terminal Washingtonian will ever have to shoot themselves or use other violent means again. We hope someday to be able to say the same for patients in the other 48 states," said Barbara Coombs Lee, president of the national advocacy group Compassion and Choices.

 Also: Oregon voters reject most ballot measures

Washington's ballot measure, officially Initiative 1000, was patterned after Oregon's decade-old "Death with Dignity" law. It allows a terminally ill person to be prescribed lethal medication, which would be self-administered.

With about 45 percent of the expected vote counted early Wednesday in unofficial returns, I-1000 was being approved by a margin of about 58 percent to 42 percent.

The win was expected, as pre-election polling showed I-1000 with significant support. The campaign was expensive, with supporters spending more than $5 million for the victory. Opponents were outmatched in the money race, but still topped $1.3 million in spending, according to state campaign finance records.

Critics of I-1000, still decrying the measure as dangerous, said their effort at least highlighted the need for better care at the end of people's lives.

Initiative opponents, including the Catholic church, had argued that I-1000 devalued human life and suggested that it could unwittingly exploit depressed or vulnerable people who worry they've become a burden on their families.

But a majority of Washington voters agreed with the "yes" campaign's argument that terminally ill people should be afforded a medical means for ending their own lives. They also pointed to safeguards built into the law, and referred to Oregon's years of experience with a similar measure.

The campaign stirred strong emotions. The public face of the I-1000 campaign was Democratic former Gov. Booth Gardner, who suffers from Parkinson's disease, an incurable disorder that causes tremors and stiff or frozen limbs.

Gardner declared I-1000 his "last campaign." Although the popular former officeholder could not use medically assisted suicide -- Parkinson's is not considered fatal -- Gardner said he pushed the measure after coming to understand why other ill people would want the option.

Under the new law, any patient requesting fatal medication must be at least 18, declared competent and a resident of Washington state.

The patient would have to make two oral requests, 15 days apart, and submit a written request witnessed by two people. One of the witnesses must not be a relative, heir, attending doctor, or connected with a health facility where the requester lives.

Two doctors also would have to certify that the patient has a terminal condition and six months or less to live.

Since Oregon's law took effect in 1997, more than 340 people -- mostly ailing with cancer -- have used it to end their lives.

The decision on I-1000 was a personal one for 82-year-old Jean Hoggarth of Yakima. She battled breast cancer and the disease now has spread to her bones, but she voted against the initiative.

"I've had experience with people dying, but I believe it can be done peacefully," Hoggarth said. "And we have doctors today who give the best care. They should be allowed to do that all the way to the end."

Mike Dingus, a 39-year-old long-term care worker in Yakima, voted "yes."

"You don't get much choice coming in, so you should get some choice going out," Dingus said.

Outside of Oregon, advocates of similar laws haven't fared well in recent years. California, Michigan and Maine voters rejected the idea, and bills have failed in statehouses around the country.

In Washington, voters rejected physician-assisted suicide in 1991. This year's proposal differed from the earlier Washington measure -- it doesn't allow doctors to administer lethal drugs on behalf of patients who can't do so themselves.