Charlotte Foot, Health Correspondent
Although research institutes in Britain investigating cannabinoids are few and far between, this area of study is not limited to cancer.
Charlotte Foot spoke to two leading professors who specialise in the field of cannabinoids and multiple sclerosis to discover how these compounds can be beneficial for sufferers of the disease.
Each and everyday more than 100,000 people in the UK endure a condition that some scientists consider to be “worse than death”.
Multiple sclerosis, also known as MS, is a degenerative neurological disease that attacks the central nervous system. Each individual sufferer is affected differently and often experiences a range of symptoms including fatigue, muscular stiffness, pain and spasticity. The Orkney Islands in Scotland have the highest incidence of multiple sclerosis in the world, with one in every 170 women suffering from the condition.
Professor of Neuroimmunology David Baker, who specialises in the study of the disease, believes multiple sclerosis is “worse than death” due to the unpredictability and severity of its symptoms.
“People with MS are very desperate and often seek self-medication. They are willing to try almost any form of symptom relief,” explains Professor Baker, who is based at the Blizard Institute in London.
In the 1960s, multiple sclerosis sufferers who were using cannabis for recreational purposes found it alleviated their symptoms to some extent. Since, research has been conducted into the use of cannabinoids – chemical compounds found in the cannabis plant – which scientists thought were responsible for the improvement many MS patients observed.
“Cannabinoids are another piece of ammunition in the armoury that doctors can use to treat this very complex condition,” says Chair of Clinical Neuroscience Professor John Zajicek.
In 2001, the first large scale clinical trial was conducted investigating anecdotal evidence from sufferers that compounds in the cannabis plant primarily eased the most common of all the symptoms encountered in multiple sclerosis: muscle spasticity. The Cannabinoids and Multiple Sclerosis (CAMS) study was led by Professor Zajicek, who undertakes his research at Plymouth University’s Peninsula Schools of Medicine and Dentistry. The trial was funded by the Medical Research Council and involved 630 patients who were given either tetrahydrocannabinol (THC) – the primary psychoactive compound found in the cannabis plant – or a placebo drug. After 15 weeks, 60% of patients taking THC reported that the severity of their muscle spasticity and pain had improved.
Research has also been conducted into whether THC has the ability to slow down the progression of multiple sclerosis. In 2008, almost 500 patients suffering from progressive forms of the condition participated a considerably longer trial – the Cannabinoid Use in Progressive Inflammatory brain Disease (CUPID) study – for between three and three-and-a-half years. The trial, also led by Professor Zajicek, was partly successful and found that the speed of progression was reduced in one sub group of patients.
Studies into the use of cannabinoids to alleviate multiple sclerosis symptoms appears to be much more advanced than research into these compounds and other conditions – such as cancer – demonstrated by the size of clinical trials undertaken.
“I think the strongest evidence is for the ability of cannabinoids to relieve MS sufferers symptoms,” explains Professor Zajicek. “It’s been tested a lot more actively and we have a more extensive understanding of it. I have no doubt that these compounds help patients’ symptoms. In other areas, such as cancer, there is much less proof. I don’t feel the evidence for the anti-cancer effects of cannabinoids is very convincing.”
The progress of research into cannabinoids and multiple sclerosis was also highlighted three years ago in 2010, when a British
pharmaceutical company, GW Pharmaceuticals, licensed the first cannabinoid-based medicine in the world. Sativex, an oral mouth spray, was developed to alleviate spasticity caused by MS and is formed from a combination of THC and cannabidiol – a non-psychoactive compound. However, it is impossible to dissociate the psychoactive element of THC from its benefits for patients, which means the product has the possibility to cause psychoactive side effects.
“The problem with Sativex is there is a small window of opportunity between it having some effect and causing the patient to become psychoactive, which makes Sativex difficult to dose,” says Professor Baker, who has specialised in the study of cannabinoids and MS for 14 years.
Some would argue any medication that relieves the symptoms of a condition considered “worse than death” should be equally available to all of its sufferers. Yet doctors are only able to prescribe Sativex in very few areas of the country, because the majority of local Primary Care Trusts (PCT) across the UK have decided not to fund the drug due to its cost. This is referred to as ‘postcode prescribing’ and has created the perception that Sativex is an ‘exclusive’ or ‘selective’ treatment, despite it being designed to treat one of the most commons symptoms of MS. Depending on the dosage, if a patient uses two to four sprays of Sativex a day, it would cost between £1500 to £2000 a year, which Professor Zajicek argues is less expensive than some existing drugs that are used to treat the symptoms of MS.
He is not allowed to prescribe Sativex to multiple sclerosis sufferers where he works in Plymouth because the local PCT are not providing financial support for the drug.
“It’s very difficult for people who make rationing decisions in the NHS to really understand the benefits of these drugs on patients’ symptoms, “ argues Professor Zajicek. “It’s different for cancer patients where you can demonstrate that a drug is able to extend someone’s life. In multiple sclerosis, it’s very difficult to measure improvement in terms of fatigue and muscle stiffness. Those don’t count so much on the quality of life measure that is currently used.”
Professor Zajicek also believes wider issues concerning the decision process for the funding of new drugs and treatments needs to be addressed.
“The procedure used by the National Health Service to decide whether a drug is cost effective or not is not particularly good and it isn’t very well suited to treatments for more chronic conditions like multiple sclerosis.”
Professor Zajicek hopes that postcode prescribing will be overcome when the new NHS arrangements begin in April.
“As a society we need to decide whether we’re able to afford better treatments to improve the quality of peoples’ lives, which will require more funding to be spent on the NHS at a time when we’re being asked to reduce our budget.”[/two_third] [one_third_last]