VACCINATION AGAINST EFFECTS OF COCAINE, PCP MAY BE POSSIBLE

(New Orleans) -- Designer antibodies might be used someday to immunize
people against cocaine and other drugs to block the rush that users
crave.

If these vaccines fulfill their promise, they could revolutionize
emergency treatment for the use of PCP and amphetamines. And though
they will not cure addiction, they also could help people who want to
kick the habit, researchers say.

"Our goal would be to protect against the sudden unexpected urge to
use, so that if the patient used it, he wouldn't get the effects,"
said Dr. Michael Owen, a pharmacologist at the University of Arkansas
for Medical Sciences who hopes to begin tests this year on a
PCP-overdose treatment.

All of the illegal drugs have molecules so tiny that they sneak
unnoticed through the body's immune system. To create antibodies,
researchers must hook the molecule to a protein big enough to set off
the immune system's alarms.

The drug-plus-protein can be injected directly, to prompt the body to
make its own antibodies. Or scientists can create the antibodies by
working with laboratory animals and inject the antibodies into patients.

Either way, the antibody grabs the drug in the bloodstream before it
gets to the brain.

At least, that is how it has worked in animals so far.

Antibodies could be used to treat an overdose or block a drug's
effects for a longer period, perhaps a month or more.

Both PCP and methamphetamine last for days in the body, unlike
cocaine, which is metabolized in 20 minutes or so.

PCP intoxication can be fatal, and both it and amphetamine psychosis
can leave permanent mental scars, said Frank Vocci, head of
medications development for the National Institute on Drug Abuse and
Alcoholism.

The ability to bind the drugs to antibodies could be a major leap
forward in treating them, he said.

Cocaine addiction is a much bigger and trickier problem. More than two
million people need treatment. About 900,000 a year start treatment,
but at least three-quarters go back to the drug, Vocci said.

"Maybe if we had something to help them out for the initial period, it
might boost the efficacy and keep them in longer," he said.

Scientists involved in the research discussed their work Monday at a
meeting of American Chemical Association in New Orleans.