EXPERIMENTAL DRUG MAY HELP PCP ADDICTS

NEW YORK, Aug 25 (Reuters Health) -- A monoclonal antibody that blocks the
effect of PCP, or phencyclidine, may one day be useful as a treatment for
recovering addicts, according to results of a new study in rats.

PCP, also known as "angel dust," causes hallucinations and psychotic and
violent behavior. A 1997 survey conducted by the National Institute of Drug
Abuse suggested that 2% of US high school seniors had used the drug in the
previous 30 days.

The monoclonal antibody, an immune system molecule that is produced in mice
and binds to PCP, appears to reduce the effects of the drug when given to
animals, according to a report presented Monday at the American Chemical
Society meeting in New Orleans.

A single injection of the antibody appeared to blunt the effect of the drug
for up to 2 weeks, said lead study author Dr. S. Michael Owens in an
interview with Reuters Health.

"In terms of humans, that would be equivalent to a month or two after
administration," said Owens, a professor of pharmacology and toxicology at
the University of Arkansas for Medical Sciences in Little Rock.

"It's very long lasting," Owens said. The antibody, by binding to PCP, "acts
like a sponge in the bloodstream" to keep the drug from going into the
brain, he said.

More research is needed before it is clear whether or not such an antibody
would be safe and effective in humans. Antibodies developed in mice may be
recognized and destroyed by the human immune system as foreign, although
such molecules can be "humanized" or mouse protein replaced by human protein
to help prevent the destruction of the antibody.

"We envision this as the first step in eventual human use," Owens said. An
injection of the antibody might help blunt the effect of the drug while a
person is struggling to overcome addiction, however, it is not a "cure," he
said.

"We would never envision this as something that cures drug abuse. It would
have to be used in conjunction with a treatment plan," he said. "They would
enter a treatment program, they would be in counseling, but if there was
something in their life that makes them go back to the drug, they wouldn't
get any effect."

"We don't think this medication would work unless they want to cure
themselves," Owens said.