Pain Specialists Warn of Overdose Danger If Methadone Is Preferred for Pain
Two-thirds of states include methadone on preferred drug lists for Medicaid patients
Two-thirds of states prefer methadone above other opioid medications to treat chronic pain, particularly in low-income residents — a practice that pain experts say adds unnecessary risk.
Physician leaders at the American Academy of Pain Medicine (AAPM) have released a position paper to warn all states and private insurers that methadone should not be considered a drug of first choice for chronic pain and should be prescribed only by health-care professionals experienced in its use or who have received special training.
“The poor are more likely to be prescribed methadone because it is inexpensive,” said AAPM President Lynn Webster, MD. “With increasing regulation and legislation to curb overdose deaths, it is ironic that public health-care programs may be in part responsible for introducing harm through coverage directives.”
In crafting the position paper, AAPM physicians pointed to evidence that methadone — the medication long associated with addiction treatment — contributes disproportionately to opioid-related poisoning deaths when prescribed for pain. Methadone represents only about 2% of opioid prescriptions, but is associated with one-third of deaths, as reported by the Centers for Disease Control and Prevention (CDC).
States’ preferred drug lists (PDLs) are designed to deliver clinically appropriate medications in a cost-effective fashion for publicly funded health plans, specifically Medicaid. If a drug does not appear on a state’s PDL, an extra step — such as prior authorization by the state agency or certification by the prescribing physician — typically is needed before dispensing through the program can occur.
The AAPM analysis shows that 33 states designate some formulation of methadone as a preferred analgesic; two (West Virginia and Nevada) designate it as non-preferred; and 13 do not mention methadone. Two states (South Dakota and North Dakota) have not published current PDLs.
Methadone is less expensive compared with other opioids prescribed for pain, but its frequent appearance on formularies as a drug of first choice may prove costly in other ways, the AAPM says. A Pulitzer Prize-winning investigation by the Seattle Times showed that after designating methadone as “preferred,” Washington state saw the number of deaths linked to methadone double, mainly in lower-income areas.
The use of methadone as an analgesic has increased. By 2009, methadone-related deaths had risen six-fold over the previous decade; during that same year, nearly 4 million methadone prescriptions were written for pain. Webster said that prescriber certification specific to methadone should be considered, given the medication’s unique pharmacologic profile among pain medicines.
“Methadone is effective for many pain conditions. However, it is eliminated from the body at a slower rate than many other medications,” Webster said. “Its long, variable half-life averages around 48 hours but can be up to 100 hours.”
In addition, Webster said, methadone can interact with other drugs the patient may be taking. Some doctors prescribe methadone as if it were like other pain medications, he said, and some patients defy their doctors’ orders and take extra pills when in pain or mix methadone with unauthorized central-nervous system depressants, such as alcohol and anti-anxiety medications.
“Doctors need clear guidelines on how to prescribe methadone,” Webster concluded. “And patients need to follow medical instructions to the letter.”
Source: AAPM; March 6, 2014.