Canada approves marijuana-based pain spray

Health Canada has approved Sativex® (Cannabis sativa L. extract) a new drug developed as adjunctive treatment for the symptomatic relief of neuropathic pain in adults with multiple sclerosis (MS). Canada becomes the first country in the world to approve Sativex, a novel prescription pharmaceutical product derived from components of the cannabis plant shown to have therapeutic properties. Sativex is administered via a spray into the mouth.

Health Canada has approved Sativex with conditions, under the Notice of Compliance with Conditions (NOC/c) policy. This authorization reflects the promising nature of the clinical evidence which will be confirmed with further studies. Products approved under Health Canada’s NOC/c policy, have demonstrated promising benefit, are of high quality and possess an acceptable safety profile based on a benefit/risk assessment for the approved use.

“Effective pain control and management are extremely important in a disease like MS,” said Dr. Allan Gordon, Neurologist and Director of the Wasser Pain Management Centre, Mount Sinai Hospital, Toronto, Ontario. “The approval of Sativex in Canada reflects the urgent need for additional treatment options in the field of neuropathic pain in MS.”

Neuropathic pain
Pain is a common symptom of MS occurring in up to 86 per cent of people with MS. 1 Neuropathic or nerve pain can occur spontaneously or can be provoked by touch, temperature or movement. It is estimated that 50 per cent of people with MS suffer from chronic neuropathic pain. 2,3,4 The most common descriptions of neuropathic pain are of freezing, cold or burning sensations usually of the limbs and most often of the lower extremities.5 Many individuals with neuropathic pain respond inadequately to current treatment options.6,7

“It’s hard to explain to someone who has never felt this type of pain. It’s like being plugged into an electric socket all the time,” said Steve Walsh, who suffers from MS and has lived with neuropathic pain for five years. “At times, putting on clothes or anything touching me can be too much to take,” he added.

Data demonstrates efficacy
While there is no complete cure for MS or neuropathic pain, a double-blind placebo controlled parallel group study demonstrated that Sativex provided significantly greater pain relief than placebo. Sativex also significantly reduced pain-related sleep disturbance.

Principal components
A product resulting from the pioneering research efforts of UK-based GW Pharmaceuticals plc and marketed in Canada by Bayer HealthCare, Pharmaceuticals Division, Sativex is the first product indicated in Canada as adjunctive treatment for the symptomatic relief of neuropathic pain in MS.

Its principal active cannabinoid components are delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). The ratio of THC to CBD in Sativex is 2.7 mg : 2.5 mg per spray, ensuring a standardized dose is delivered each time it is used.

“The approval of Sativex is good news for the Canadian MS community. People living with MS and neuropathic pain need new options to address their pain. Sativex will likely be welcomed by the many people with MS, whose quality of life has been further compromised with neuropathic pain,” said Dr. William J. McIlroy, National Medical Advisor, MS Society of Canada.

How Sativex works
Sativex is administered through a spray pump under the tongue or on the inside of the cheek, providing reliable, self-administered pain relief. The spray formulation allows for more flexible dosing than an oral tablet, well suited to the variable nature of neuropathic pain experienced by people with MS.

“Because Sativex is designed for self-administration, this allows for flexible dosing and puts the patient in control of their pain,” said Dr. Gordon. “This is very important since pain severity varies between different patients and even in the same patient at different times.”

Sativex and side-effects
In clinical trials, the most frequent side-effects included nausea, fatigue, dizziness and application site reactions. Side-effects were usually mild or moderate in severity and often resolved with down-titration or interruption of treatment.8

Sativex is expected to be available through Canadian pharmacies by late Spring 2005.

Multiple sclerosis (MS) in Canada
MS is a disease of the central nervous system and is the most common neurological disease affecting young adults in Canada. Approximately 50,000 Canadian men and women have the disease and each day approximately three more people are diagnosed. MS is most often diagnosed in people between the ages of 20 to 40 years of age.

Source : GW Pharmaceuticals