Last week, NICE finally published the long-awaited guidance on Cannabis-based medicinal products. (www.nice.org.uk/guidance/NG144). This has been extensively reported on in the mainstream media and whilst it is a step in the right direction for the use of Sativex® for patients with spasticity associated with MS (and a reversal on the initial draft guidance), it won’t allow all patients to receive medicinal cannabis straight away.
Currently, there are only two medicinal cannabis products that are licensed Sativex® (used in spasticity in patients with MS) and Epydiolex® (which is used for some epilepsies). For MS patients, the NICE guidance recommends that Sativex® is offered as a 4-week trial to treat moderate to severe spasticity in adults with MS if other treatments have failed, and GW Pharma (manufacturer of Sativex) offer their trial-for-response for patients. Patients need to show a reduction of spasticity related symptoms of at least 20% at the 4-week point to be able to continue on treatment. After the four week period, NHS trusts or the local GP (via CCGs) will need to continue to fund the treatment.
Medicinal cannabis products go through extensive research (trials) to gain a license to be able to be prescribed and this is unlike some of the readily available CBD oils (available from pharmacies and health food shops). The CBD oils which are available to be purchased without a prescription do not have the same regulations regarding manufacturer and the potency and purity may vary between batches and products.
Over 120 naturally occurring cannabinoids have been found in the cannabis plant including the psychoactive THC (tetrahydrocannabinol) and the non-psychoactive CBD (cannabidiol). Sativex® is known to have a THC:CBD ratio of 1:1 and the CBD oils available have a range of ratios. It is not fully known which cannabinoid has the main effect on spasticity and it is likely that both THC and CBD have a beneficial effect.
By acting on the liver, both THC and CBD are known to affect the functioning of certain liver enzymes which means that medicinal cannabis products can interact with other commonly used medication (examples include warfarin, modafinil, opioid analgesics (eg morphine)) and cause their efficacy to be enhanced or diminished. If you are taking CBD oil and are unsure of how this is interacting with your other medication, please let your pharmacist, nurse specialist or doctor know so that any interactions can be managed appropriately (which may include additional blood tests to check your liver function).
It is important to realise that the publication from NICE was guidance which unlike a technology appraisal, means there is no compulsion for any NHS Trust to offer Sativex® and no additional funds are available to the local economy or commissioners to offer this product. The guidance is only guidance and for your local hospital trust to be able to offer the treatment it will need to be presented to the local formulary committees, who will work with the local health economy to see how this medication can be funded and offered locally.
If you think you will benefit from Sativex for spasticity discuss with your MS team who will advise you of local pathways and timescales. At present, the timescale is likely to be months and not weeks.
Barts-MS Neuroscience Pharmacist