CANNABIS PAINKILLER IS APPROVED

Canada has become the first country in the world to approve the sale of a
cannabis-based prescription painkiller.

Cannabis sativa L. has won approval from Health Canada regulators for
treatment of a severe form of pain common among sufferers of multiple
sclerosis, but it may also find favour with those with nerve pain related to
conditions ranging from shingles to cancer.

The drug, marketed in Canada by Bayer HealthCare under the brand name
Sativex, is sprayed under the tongue or inside the cheek.

While it contains the active ingredients that give pot smokers their buzz,
including delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), users
will not get stoned.

"These people are not feeling intoxicated by the drug, partly because the
type of cannabinoids that have been isolated and purified work more
specifically at the targeted pain receptors," said Dr. Virginia Devonshire,
a neurologist at the University of British Columbia.

Patients who will be prescribed the drug will also be suffering from
neuropathic pain, which is excruciating and can be provoked by movement,
touch or temperature.

"It's like being plugged into an electric socket all the time," said Steve
Walsh of Milton, Ont., who has endured neuropathic pain in his hand for five
years since being diagnosed with MS.

He said that, at times, simple things like holding money in his hands "can
be too much to take." None of the numerous painkillers he has tried to date
provided any real relief, he said.

"There's a huge community of people with MS who are looking forward to
this," Mr. Walsh said. "Personally, I would be tickled pink if it helped
with the pain so I could do things like pick up my grandchild without
suffering."

Sativex should be on the market in Canada before summer. The price of the
drug has not yet been established.

While a number of drugs use synthesized forms of cannabis, this is the first
to actually use marijuana extracts. The British drug company that developed
Sativex, GW Pharmaceuticals, has been harvesting 40,000 pot plants in a
secret location to produce the drug.

Dr. Allan Gordon, a neurologist and director of the Wasser Pain Management
Centre at Mount Sinai Hospital in Toronto, said that while the drug is
getting a lot of attention because it is derived from cannabis, the real
story is that there is an "urgent need for additional treatment options in
the field of neuropathic pain and MS."

It is estimated that more than half of the 50,000 Canadians who have
multiple sclerosis suffer from chronic neuropathic pain, which is often
described as freezing or burning sensations in the extremities. The
condition has long puzzled researchers because it tends to be experienced in
areas of the body that appear uninjured. It is also notoriously difficult to
treat.

Many people with MS treat the pain by smoking marijuana, which is where
scientists got the idea for developing a prescription drug derived from
cannabis.

The problem with smoking marijuana is that the dose is hard to regulate and
it can be difficult to get the drug legally. Mr. Walsh said that he tried
smoking pot once to treat his pain, but he didn't like the experience. "I
prefer to have something that's much more controlled and scientific," he
said. "And, as an ex-smoker, I really don't want to get into the smoking
habit again."

Sativex provides 2.7 milligrams of THC and 2.5 mg of CBD in a standardized
dose with each spray.

Dr. Gordon said the spray is better than a pill because it "allows for
flexible dosing and puts the patient in control of their pain. This is
important since pain severity varies between different patients and even in
the same patient at different times."

In clinical trials, Sativex provided more pain relief than a sugar pill, but
its efficacy was not compared directly to other painkillers. In the clinical
trials, side effects of the drug -- which included nausea, fatigue,
dizziness and reactions at the site where it was sprayed -- were deemed to
be mild.

Multiple sclerosis is a bedevilling disease of the brain, spinal cord and
optic nerves that can affect muscle control, strength, balance, vision and
sensation. For reasons that are unclear, the body's immune system
malfunctions and starts attacking myelin, the protein coating that surrounds
and protects nerve fibres.