08/08/2007 00:00:00
Canada: Cannabis-based spray painkiller approved for cancer patients
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Health Canada has approved a new cannabis-based painkiller to help
alleviate the suffering of cancer patients.
The drug, sold under the brand name Sativex, is administered by spraying
it into the mouth. It is intended to be used by cancer patients
suffering from neuropathic or nerve pain, which is excruciating and
difficult to control.
"It's an adjunctive treatment, an add-on. You take it in addition to
opioids (such as morphine)," Allan Gordon, director of the Wasser Pain
Management Centre at Mount Sinai Hospital in Toronto, said in an interview.
"It will be helpful as another way to reduce pain," he said.
Dr. Gordon said that 60 to 90 per cent of people with advanced cancer
experience significant pain and there are far too few pain-relief
options available to them.
He estimated there are at least 100,000 Canadians with cancer who are
dealing with severe pain at any time.
"There's an unmet need there and finally we're seeing some attention
being paid to the problem," he said.
While Sativex contains the active ingredients that give pot smokers
their buzz, including delta-9-tetrahydrocannabinol (THC) and cannabidiol
(CBD), users are unlikely to get stoned. When people are in severe pain,
the drug provides relief rather than pleasure, much like opium and
heroin used medicinally.
Each spray delivers a fixed dose of 2.7 milligrams of THC and 2.5 mg of
CBD. Patients can control the number of doses, but it is recommended
they not exceed 14 sprays daily.
"We have to reference this drug as a pain-management therapy. It's not a
recreational vehicle," Dr. Gordon said.
He also noted it's an expensive and inefficient way to get high compared
with smoking marijuana or hashish.
Sativex, by U.K.-based GW Pharmaceuticals, is marketed in Canada by
Bayer Inc.
The drug costs roughly $125 per vial (prices vary by province and do not
include dispensing fees). Each vial contains 51 sprays. The average
daily dose is five sprays, which translates into an average cost of
about $12.25 a day. The prescription drug is covered by most private
insurance plans, but not yet by any provincial drug plans.
In 2005, Canada became the first country in the world to approve the
sale of a prescription painkiller derived from cannabis. Sativex was
initially allowed on the market for the treatment of severe pain
associated with multiple sclerosis.
It belongs to a class of drugs known as cannabinoids. A report issued
yesterday said the sale of cannabinoids has soared by 45 per cent
worldwide in the past year, to $709-million (U.S.)
In addition to Sativex, the class of drugs includes Rimonabant, a
high-profile anti-obesity drug from Sanofi-Aventis, along with Marinol
and Cesamet, drugs used to treat nausea and vomiting in cancer patients
undergoing chemotherapy.
Scientists are excited by the prospect of this class of drugs because
there are about 10 times as many cannabinoid receptors in the brain as
opioid receptors, meaning the drugs should be more effective at blocking
pain.
Cannabis-based drugs also appear to have fewer side effects than those
derived from opium. Some users of Sativex complain that the spray leaves
an odd taste and can cause minor gastrointestinal problems. Drugs such
as codeine and morphine, on the other hand, can cause severe
constipation and drowsiness. Many physicians also hesitate to prescribe
opioids because they are highly addictive.
An estimated 159,000 Canadians will be diagnosed with cancer this year,
and 72,700 will die of cancer in 2007, according to the Canadian Cancer
Society.
http://www.theglobeandmail.com/
Source:
http://www.ukcia.org/news/shownewsarticle.php?articleid=12781
Author:
Globe and Mail via UKCIA
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