Inquest reaches decision over Sativex

An inquest at Sheffield Medico Legal Centre, UK, into the death of 69-year-old Rene Anderson six months after she took part in a three-week Sativex trial, has reached a decision over her death.

Christopher Dorries, the coroner at the inquest, told the court that: 'Mrs Anderson died on 3 March 2004 in the Northern General Hospital as a consequence of prolonged immobility following an illness for which she had been admitted on 28 October 2003. On the balance of probabilities, an idiosyncratic reaction to a trial drug (either alone or in combination with other medications) was at least a significant contributory factor to the initiation of this illness.'

The term idiosyncratic reaction was defined by the Coroner as 'unusual, unexpected and individual', and consequently GW Pharmaceuticals, the producer of Sativex, believes it has 'no wider relevance for patients or for the medicine'.

'Mrs Anderson's immobility was unresolved despite over four months of hospital care and complicated by a wide range of other drugs,' stated GW following the verdict. The company reported the other medications to have included tramadol, haloperidol, nitrazepam, simvastin, citalopram, losartan, frusemide, atenolol and doxazosin, a number of which specifically name 'confusion' as a side-effect, and Dorries did raise the possibility of 'serotonin syndrome', in which the interaction of drugs leads to an excess of serotonin in the brain, before saying that he 'found little reason to believe that this syndrome alone has brought about Mrs Anderson's death'.

GW went on to add: 'While the case is very sad by its nature, GW does not believe it raises any new or additional safety concerns about Sativex. During October 2003, Mrs Anderson developed confusion and other intoxication effects and stopped taking Sativex. At the end of October 2003, a full four months before her death, a urine test confirmed that there was no presence of cannabinoids in her body.'

However, such evidence is no guarantee of Sativex's innocence, as Dorries stated: 'There is no known science upon which a clear finding could be made of a connection between the trial drug and the continuation of the illness beyond the point at which the compounds had passed from the body'

Anderson, who received 42 doses of Sativex - which equates to 'less than four days' worth for a typical patient' according to GW - to ease pain and numbness of the limbs, had a 25-year history of diabetes mellitus and suffered from resistant hypertension, clinically significant depression and hyperlipidaemia. According to Dorries, she died from a combination of 'acute renal failure, acute tubular necrosis, ARDS following resolving pneumonia due to immoblility arising from "toxic brain syndrome" [defined by Dorries as meaning that the 'initial drug reaction, whether in combination or singly, must have been a significant contributory factor in at least the initiation of the illness'], and diabetes mellitus'.

GW is licensed by the UK Home Office to undertake 'a pharmaceutical r&d programme to develop cannabis-based prescription medicines'. Currently in Phase III trials for the treatment of spasticity and neuropathic pain in Multiple Sclerosis, peripheral and general neuropathic pain and cancer pain, Sativex contains the active cannabinoid components delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Administered through a spray pump under the tongue or on the inside of the cheek, it gained its first approval as a prescription medicine in Canada in April 2005. It is marketed by Bayer in the UK and Almirall Prodesfarma in the rest of Europe.

Shares in GW, despite falling as low as 100p, ended 16 December at 107.5p, marking a 14.5p (or 12%) drop.

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