Office-based Tx of opioid addiction now feasible. (Buprenorphine Approved).

Approval of the partial opioid agonist buprenorphine for treating opiate dependence has paved the way for office-based treatment of opioid addiction and expanded access to treatment for hundreds of thousands of heroin addicts nationwide.

Two sublingual formulations have been approved. Buprenorphine, to be marketed as Subutex, is given during the first few days of treatment under supervision. A combination of buprenorphine and naloxone, to be marketed as Suboxone, is given during the maintenance phase. Naloxone is added to deter abuse; if tablets are ground up and used intravenously, the naloxone component, which is not well absorbed sublingually, precipitates withdrawal symptoms.

Buprenorphine is the first narcotic drug for treating opiate dependence that can be prescribed in an office setting. The other three approved agents are methadone and LAAM (L-alpha-acetylmethadol)--schedule II drugs that can be dispensed only in special treatment programs-and the opioid antagonist naltrexone.

Subutex and Suboxone are schedule III drugs. Under the Drug Abuse Treatment Act of 2000, these can be prescribed in office settings by physicians who are specially trained and meet certain requirements. Medications to treat opiate dependence that are less tightly controlled than schedule II drugs can be prescribed in office settings, with various measures to deter drug abuse and illegal diversion.

"It is hoped that with this new law and the availability of these new drugs, treatment will become available to many more patients," said Dr. Cynthia McCormick, director of the Food and Drug Administration's division of anesthetic, critical care, and addiction drug products, Rockville, Md. About 70% of the nearly 1 million U.S. opiate addicts lack access to treatment because of too few treatment programs or slots in existing methadone programs.

The availability of buprenorphine is not expected to replace methadone therapy.

Buprenorphine is considered less likely to cause psychological or physical dependence than schedule II drugs. Buprenorphine is not a cure for addiction, but is for symptomatic treatment. It was developed for use in the context of addiction therapy that includes psychotherapy, she noted. The risk of respiratory depression with high doses or overdoses is less than with other opioids, but fatal cases of respiratory depression have been reported in France where it has been available for several years, especially when combined with alcohol or other CNS-depressant drugs.