The first three years of buprenorphine in the United States: experience to date and future directions.

Buprenorphine, primarily as the buprenorphine/naloxone combination, has been available in the United States for office and specialty treatment program-based care since 2003. The existing evidence, collected primarily from federal sources, indicates that access to this type of treatment has expanded, that more than 50% of the 12,000 physicians able to provide this care are not addiction specialists, that buprenorphine diversion is low, that physician scrutiny by federal agents is infrequent, and among those receiving treatment patient acceptance is high. Implementation has been slowed because of physician training and support needs, reimbursement, and limits on the number of patients each physician can treat. As a result there are geographic variations in access and unmet treatment needs. The United States Congress has moved twice to loosen numerical limitations, now allowing each physician to treat up to 100 patients. Future research and evaluation are needed to ensure that opioid-dependent patients receive optimal care with buprenorphine.