Misplaced concerns about cost and safety may be leading many state Medicaid programs to mistakenly restrict the use of buprenorphine for the treatment of opioid addiction, despite the drug's approval by the Food and Drug Administration for that purpose in 2002.

Most Medicaid programs limit buprenorphine use by requiring prior authorization to fill prescriptions, limiting treatment duration, or imposing other requirements, such as drug screening before prescription can be reauthorized.

A group of Massachusetts researchers recently sought to determine whether such restrictions are justified. "The evidence does not support rationing buprenorphine to save money or ensure safety," wrote Robin Clark, Ph.D., a senior director with the Center for Health Policy and Research and an associate professor of family medicine and community health and quantitative health sciences at the University of Massachusetts Medical School, and his colleagues in the August Health Affairs.

The researchers came to that conclusion after they compared spending, the use of services related to drug-use relapses, and mortality for 33,923 Massachusetts Medicaid beneficiaries receiving either buprenorphine, methadone, drug-free treatment, or no treatment during the period 2003 to 2007.

They found that buprenorphine offered several attractive features as an opioid-dependence treatment. For example, buprenorphine can be prescribed by a physician and taken at home without the stigma and daily demands of acquiring methadone injections, which must by law be administered at an approved clinic. "Enrollment patterns suggest that buprenorphine has expanded treatment access," they said.

Despite concerns about safety, mortality rates were similar for buprenorphine and methadone. In contrast, mortality rates were 75 percent higher among those receiving drug-free treatment, and more than twice as high among those receiving no treatment, compared with those receiving buprenorphine. Buprenorphine carries a lower risk of overdose than the stronger opioid methadone and is formulated with naloxone to prevent the practice of crushing and injecting the drug to achieve a greater opioid effect.

"Buprenorphine is also more tightly bound to the opioid receptor than other opioids and therefore may protect patients by blocking out other drugs," said Clark and colleagues.

But the idea among some health officials that buprenorphine is more costly than methadone turns out to be mistaken: "After adjustments for confounding factors, total health care spending for patients using buprenorphine treatment were slightly lower than for methadone, despite more frequent relapse events for buprenorphine. Longer and more expensive hospital stays among methadone patients accounted for the largest portion of the difference," the researchers pointed out.

They expressed their concern that significant reductions in buprenorphine use could have the unintended effect of increasing costs and reducing the overall use of opioid substitution therapy, perhaps even contributing to "higher mortality among Medicaid beneficiaries with opioid addiction."

"This analysis shows the importance of considering a broad range of costs and outcomes when attempting to implement targeted cost reductions," they said. "Failing to consider the impact of medications or other expensive treatments on total health care spending and outcomes could have the unintended effect of increasing costs and placing patients at greater risk."

Funding for this study was provided by the Robert Wood Johnson Foundation's Substance Abuse Policy Research Program.

An abstract of "The Evidence Doesn't Justify Steps by State Medicaid Programs to Restrict Opioid Addiction Treatment With Buprenorphine" is posted at <http://content.healthaffairs.org/content/30/8/1425.abstract#xref-corresp-1-1>.