BUPRENORPHINE is a tongue twister. Never mind.

This opiate blocker, which federal authorities are introducing in 14 cities, including Baltimore, offers unusual promise in helping stabilize heroin users' lives and getting them started on the path to recovery. Moreover, for the first time, primary care physicians will be able to address abusers' detoxification and withdrawal needs during regular office visits.

Buprenorphine is no miracle cure, nor is it suitable for all heroin users. Yet its arrival is a blessing, because it presents a new treatment option for heroin addicts wanting to break the habit.

Unlike methadone, the most commonly used opiate blocker, and the newer LAAM, buprenorphine does not require enrollment in a clinical program. After a physician prescribes buprenorphine, it can be taken like a high blood pressure pill or allergy medication. This means addicts won't have to wait for scarce treatment slots and stand in line every day outside a methadone clinic. But buprenorphine is more expensive than methadone.

Of Baltimore's estimated 55,000 drug addicts, roughly 36,000 use heroin, Dr. Peter Beilenson, the city's health commissioner, estimates.

Under federal guidelines, physicians prescribing buprenorphine must have special training. That is going on. Baltimore Substance Abuse Systems Inc., which supervises treatment for the uninsured, plans to have 25 physicians certified for buprenorphine by the end of this year. The goal is to double that number next year. When that happens, BSAS hopes to divert 1,500 of its stable clients to buprenorphine. Since many of those clients have jobs, they should be able to contribute to treatment costs.

The introduction of buprenorphine represents a milestone in drug treatment in this country. For the first time, an opiate blocker has been approved as a prescription drug. And though that doesn't guarantee success, it diminishes the stigmatization of addiction and adds a long-awaited - and welcome - new weapon to the arsenal of treatment.