Tuesday July 4 7:43 AM ET
By Patricia Reaney
LONDON (Reuters) - 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 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