Risky Business
Last July, researchers from the CDC reported that increases in prescriptions for opioid analgesics paralleled and may have contributed to an annual 18% increase in unintentional drug-poisoning deaths from 1990 to 2002.
From 1999 to 2002, the number of death certificates listing methadone poisoning rose by 213%, according to Dr. Leonard Jduring this period, while sales through narcotics treatment programs rose only 43% (Pharmacoepidemiol. Drug Saf. 2006;15:618–27).
'We are getting this very complicated sleep-disordered breathing, which used not to be in our lexicon.' DR. BECK
Methadone Prescribing on the Rise
Not without irony, Dr. Webster said physicians turned to methadone for treatment of pain in part because they believed it was safer than other opioids and less likely to bring regulatory sanctions. When OxyContin abuse became a public policy issue, they saw methadone as a drug with little street value or abuse potential.
“Physicians think it is safe because it has been used for addiction so many years,” he said.
Health insurers also appear to have played a role. Methadone is the cheapest opioid by far. One estimate puts the monthly cost to pharmacists as $8 for an oral dose of 5 mg taken three times a day, based on wholesale prices. In comparison, chronic pain therapy with generic sustained-release morphine would cost $101.50; MS Contin, $113.50; OxyContin, $176.50; and Duragesic, $154 (Am. Fam. Physician 2005; 71:1353–8).
Confronted with such steep price differences, some health plans reportedly have made methadone their drug of choice when an opioid is prescribed for pain. In many cases, Dr. Beck said, that is why methadone is being prescribed to older pain patients with comorbidities and other medications that can interact with methadone.
“It is really irresponsible of insurers and HMOs, of anyone who sets up a formulary that [designates] the most dangerous in its entire category as the first-line agent to be used. I think that is unconscionable,” she said.
Formularies also are responsible for an increase in methadone prescribing by primary care physicians who are not familiar with its unique characteristics, according to Dr. Howard A. Heit, a chronic pain specialist certified in addiction medicine who practices in Fairfax, Va. “Are we forcing doctors to use a medication that they don't have the knowledge to use, which could be fraught with major complications, which will cost more in the long run?” he asked during an interview.
Dr. Heit served on a U.S. Substance Abuse and Mental Services Administration panel that reported in 2004 on nationwide increases in methadone-related deaths. The panel cited as a likely factor a fivefold increase from 1998 to 2002 in the volume of methadone distributed through pharmacies. The risk of apnea was not considered because it was not an issue at that time, he said.