Alarmed by evidence that hundreds of patients die each year from accidental overdoses of prescription pain drugs, the state of Washington will issue a public-health advisory that singles out the unique risks of methadone, a narcotic medication linked to the most fatalities.

The emergency measure, adopted Wednesday by unanimous vote of a committee of state-appointed medical experts, follows a Seattle Times investigation, "Methadone and the Politics of Pain," which detailed Washington's troubled history with methadone, a potent and cheap painkiller.

To save money, the state steers Medicaid patients, workers' compensation recipients and state employees toward methadone, a long-acting painkiller that costs less than a dollar a dose. Since 2003, at least 2,173 people in Washington have died from unintended overdoses linked to the drug, The Times found.

The poor have paid the highest price. Medicaid recipients represent about 8 percent of the adult population and 48 percent of methadone deaths.

Beginning early next week, state Medicaid officials will fax a health advisory to more than 1,000 pharmacists and drugstores about methadone, as well as oxycodone, fentanyl and morphine. That move will be followed by a written advisory from the state Department of Health to about 17,000 licensed health-care professionals.

The health advisory marks the first public acknowledgment by a powerful state committee that methadone can be more unpredictable than other pain drugs, or opioids. State officials had previously resisted attempts to single out methadone for special treatment, insisting the drug was as safe and effective as any other narcotic pain drug.

The Pharmacy and Therapeutics Committee — or P&T committee, for short — evaluates drugs for safety and effectiveness, a key step in the state's creation of a preferred drug list. On Wednesday, the committee gathered for what in years past had been a routine review and approval of methadone and morphine, the two long-acting pain drugs on the state's preferred registry.

But after a representative from the Health Care Authority — a state agency that oversees Medicaid and medical benefits for state employees — recounted Washington's "severe problem" with painkiller overdoses, the panel postponed any decision on methadone's status as a preferred drug and decided to authorize the advisory.

Duane Thurman, a program director for the Health Care Authority, told the committee that state senators were "extremely concerned" about methadone-related deaths as reported by The Times. He encouraged the committee to approve the health advisory and said, "I think it's important to do something immediately."

Dr. Barak Gaster, chairman of the committee, said during the meeting: "I think there is some sense that there are features that are unique to the way methadone needs to be prescribed and for it to be done safely."

Compared with other painkillers, methadone has a long half-life. OxyContin dissipates from the body within hours while methadone can linger for days, pooling to a toxic reservoir that depresses the respiratory system.

"Is methadone different? Yes," Dr. Jeff Thompson, chief medical officer of the state's Medicaid program, told a Times reporter during a break in the daylong session.

Last week, the state Senate Health & Long-Term Care Committee held a work group to get an update on Washington's new pain-management law. But much of the discussion focused on methadone, with lawmakers pressing for answers about the narcotic's pharmacological makeup and risks.

Committee Chairwoman Karen Keiser, D-Kent, became frustrated with Dr. Gary Franklin, medical director for the Department of Labor & Industries, which handles workers' compensation.

Keiser asked Franklin — a principal defender of the state's decision to designate methadone as a preferred drug — if the painkiller is more difficult to manage than other long-acting narcotics. When Franklin responded by discussing the toll of long-acting opioids in general, Keiser said: "Dr. Franklin, answer the question about methadone."

She later told him: "That's something I'd like to get a straight answer on. And I'm not getting a straight answer."

Franklin told lawmakers that methadone is not at the heart of the state's struggle with painkiller overdoses. "It's dose, not a specific opioid," he said.

"Almost no one dies from a single opioid. When you look at death certificates, and I've reviewed many of these at L&I, you never see just methadone or just OxyContin or just fentanyl listed," he told the committee.

"Coroners, in fact, will not ever say on a death certificate that this death is from methadone. It is always a combination of multiple opioids plus other drugs."

But a Seattle Times analysis of death certificates turned up 443 cases since 2003 in which methadone was the only drug listed when someone fatally overdosed. And this was using a conservative sift, excluding cases where the deceased had so much as a history of alcoholism.

Sen. Cheryl Pflug, R-Maple Valley, told Franklin that she was troubled even by those cases in which methadone had combined with other drugs to cause a fatal overdose.

"I don't really care that the coroner isn't willing to say this was caused by methadone," she said. "If the person has a toxic level, and they were taking methadone and other drugs known to have a synergistic, respiratory depressive effect, and they quit breathing, it doesn't take a rocket scientist to know we might have a problem."

She urged the state to create a list of factors that would caution against prescribing methadone in particular instances — for example, if a patient is taking another drug that doesn't mix well with the painkiller. "We should say, 'you can use it if,' rather than, 'you must use it unless,' " Pflug said.

A spokeswoman for the department of Labor & Industries said Wednesday that Franklin would not be available for an interview with The Times.

At the committee meeting, Sen. Mike Carrell, R-Lakewood, said two graphics distributed to the lawmakers — one showing methadone with the longest half-life, the other linking it to the most deaths — raised the question: "How could we end up pushing methadone?"

"Maybe we need some horse sense here rather than expertise on how well some of these things work," Carrell said.

Afterward, several committee members told The Times the Legislature will push to get more information about methadone and its risks.

"Across the political spectrum, I think everybody on that committee was concerned," Carrell said.

Michael J. Berens: 206-464-2288 or mberens@seattletimes.com; Ken Armstrong: 206-464-3730 or karmstrong@seattletimes.com. Database reporter Justin Mayo contributed to this report.