SINGLE INJECTION PROMISING FOR HEROIN ADDICTION

NEW YORK (Reuters Health) - A single dose of an experimental drug holds
promise for the treatment of heroin addiction, according to the results of
a small study.

The findings suggest that a new, long-lasting formulation of the drug
buprenorphine is safe and seems to prevent withdrawal symptoms for 6 weeks.
What's more, the long-lasting form of the drug, known as a "depot"
formulation, seems to block the effect of other opioid drugs, the class of
drugs that includes heroin and morphine.

"I believe the depot medication offers promise as a way to make effective
treatment more accessible to opioid-addicted patients without the need to
worry that the treatment medication itself might be misused or abused," Dr.
George E. Bigelow of Johns Hopkins University School of Medicine in
Baltimore told Reuters Health.

Lead author Bigelow said he was impressed with the drug's effectiveness in
providing long-lasting relief from symptoms of withdrawal that usually
occur when people stop taking heroin and other similar drugs.

The Johns Hopkins researcher said that more research is needed to confirm
the results of this small trial and to identify the best use of this new
formulation of buprenorphine.

Methadone, a synthetic opioid that blocks the effect of heroin and reduces
cravings for the drug, has been used for decades to treat heroin addiction.
For methadone to work, though, it must be taken every day, and patients are
usually required to make frequent visits to a methadone clinic to receive
the medication.

Buprenorphine, too, blocks the pleasure of heroin and reduces an addict's
cravings. In a tablet form, the drug is normally taken once a day.

Now, Bigelow and his colleagues report that a single injection of a
long-lasting version of buprenorphine is safe and seems effective, at least
in a small study.

The study included five people who had used heroin for an average of more
than 6 years. After receiving a single injection of the long-lasting
buprenorphine, participants were monitored for signs of withdrawal for the
next 6 weeks.

The new formulation was safe, with no major side effects reported.

Even though the study was designed to test the drug's safety, not its
effectiveness, it seemed to work in helping addicts' get off heroin,
Bigelow and his colleagues report in the January issue of the journal Drug
and Alcohol Dependence.

When participants received inpatient care after 4 weeks of depot
buprenorphine, none needed other medications to combat withdrawal symptoms.
In fact, participants did not experience clinically significant withdrawal
symptoms after receiving the buprenorphine injection.

At the end of the 6-week study, urine tests showed that all of the patients
had abstained from opioid drugs like heroin with the exception of one
person who reported using a prescription opioid drug for dental pain. Two
patients reported cocaine use.

The drug also seemed to block most of the effect of another opioid
medication that was given to the participants.

Although other forms of buprenorphine are available in the U.S., Bigelow
noted that the slow-release formulation is still experimental and has not
been approved by the Food and Drug Administration (FDA).

"Gathering sufficient data and experience for FDA approval is likely to
take a good while yet," he said.

The study was funded by the National Institute on Drug Abuse. Biotek Inc.,
which makes the experimental buprenorphine formulation, provided the study
medication. Two of the study's authors work for Biotek.

SOURCE: Drug and Alcohol Dependence, January 2004.