Pubdate: Tue,  4 Jul 2000
Source: Reuters
Copyright: 2000 Reuters Limited.
Author: Patricia Reaney

SCIENTISTS MAY USE CANNABIS TO DEVISE NEW DRUGS

LONDON,  British scientists are closer than ever to
developing drugs based on cannabis that will take away pain -- but
also take away the ``high.''

Researchers from Imperial College in London have separated
cannabinoids, the active components of the popular recreational drug,
and shown that they act on both the brain and spinal cord.

The findings will allow scientists to develop cannabinoid-based drugs
designed to target the spinal cord to relieve pain, but bypass the
brain to prevent the often euphoric high associated with using cannabis.

``We have achieved a really important step in terms of divorcing the
psychoactive side effects of cannabis from their pain-relieving
effects,'' Dr Andrew Rice told Reuters.

``What we've done is to identify the fact that there are receptors for
the cannabinoids in the pain areas of the spinal cord,'' he said.

In their research, scientists used receptors for cannabinoids on the
spinal cord, particularly the areas concerned with pain processing.

By delivering drugs directly to the spinal cord to relieve pain they
bypass the brain so there are no psychoactive effects.

New drugs based on cannabis are still years away but the findings,
published in the journal Molecular and Cellular Neuroscience, are an
important first step.

BETTER THAN MORPHINE FOR A CERTAIN TYPE OF PAIN

Rice and his colleagues said cannabinoid-based drugs would be more
effective than opioid analgesics, such as morphine, for pain caused by
spinal cord injuries and nerve damage.

``When you injure a nerve you lose the opioid receptors in the spinal
cord. That is why morphine does not work well in those situations,''
said Rice.

``What we have shown in this paper is that when you injure the nerve
the cannabinoid receptors stay,'' he said.

The British researchers followed a similar course to the development
of morphine-like drugs in the 1970s. The epidural drug delivery
system, commonly used to relieve the pain of childbirth and for
chronic and cancer pain, was developed after scientists discovered its
receptors on the spinal cord.
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