VIRUS TO CURB COCAINE CRAVINGS

Scientists have engineered a virus which may help addicts battle cocaine
addiction.

Researchers have already developed proteins that can reduce the effect
of cocaine - but it has proved difficult to slip them past the body's
defences.

The new approach uses a virus to bypass these defences, and produce
the proteins where they have most effect.

The work, by the US Scripps Research Institute, is published in
Proceedings of the National Academy of Sciences.

The researchers injected the virus - known as a phage - into rats'
noses twice a day for three days. On the fourth day, the rats received
a shot of cocaine.

The cocaine appeared to have less effect on the animals who received
the virus injections than on those who did not.

They showed less signs of behaviour typically associated with exposure
to cocaine, such as sniffing and raising themselves on to their hind
legs.

The researchers believe their work provides evidence that the virus
can successfully penetrate the defences protecting the rats' nervous
system, and begin to produce proteins to counter cocaine where they
will have the maximum effect.

The proteins are designed to either to bind to cocaine to block its
effect, or to change its chemical makeup, reducing its mind-altering
ability.

No Side Effects

The study also suggested that the phage could be repeatedly injected
without any apparent side effects.

Writing in the journal, the researchers say: "We have shown a
promising strategy in the continuing effort to find effective
treatments for cocaine addiction.

"Whereas previous protein-based treatments have relied on peripheral
drug-protein interactions, our approach delivers the therapeutic
protein agent directly into the central nervous system, the site of
drug action."

A spokesperson for the charity DrugScope said: "Recent developments in
the addiction treatment field are very interesting, but we have to be
realistic about how much they can achieve when used in isolation.

"Dependent drug users often have experienced a range of social and
psychological problems which contribute to their addiction, and these
factors must also be addressed if rehabilitation is to be successful.

"If not, the user may simply move onto other drugs to help them cope
with these underlying problems."