CBD oil: what is it & how is it prescribed?

Over the last year, cannabis oil has received considerable media attention. CBD (or cannabidiol, Epidiolex) is a purified extract from the cannabis plant. Cannabis or marijuana is well-known in the UK as an illegal recreational drug. As a psychoactive substance, it may dangerously alter brain function.

Cannabis is composed of over 100 different chemicals. A large proportion, approximately 40% of these is CBD. The non-intoxicating marijuana extract has recently been credited in treating different medical problems such as anxiety or sleep problems. Leading neurologist Dr Dora Lozsadi explains whether CBD oil is good for severe epilepsy in children and the likeliness of its future in medicine...

Is CBD oil good for epilepsy?

Cannabis was used to treat epilepsy in ancient China and Sumer. We have an increasing number of reports on the benefit of CBD in rare and severe childhood epilepsies. The conditions Lennox-Gastaut and Dravet syndromes are often associated with learning difficulties and seizures that are unresponsive to other licensed antiepileptic drugs. As the number of patients treated is still low (several hundred) clinicians continue to focus on information collection and analysis. CBD may benefit around 50% of above children. Data on adult and other epilepsy types remain scarce.

How does CBD oil stop seizures?

CBD does not directly bind to human brain cannabinoid receptors. Its mode of action is not fully understood. It is thought to modulate sites of communication between neurons (synapses). It is likely to have multiple sites of action.

How is CBD oil prescribed?

CBD oil is not widely available in the UK, however there are now a number of different types on the market. Information on benefits and side effects is limited, this means we don't yet know whether CBD’s efficacy justifies potential risks posed. Only a few are aware of the high risk of side effects. Over 90% of patients report diarrhoea, somnolence and even convulsions. In 10% these are severe enough to discontinue treatment. Therefore, while further data are collected, only selected doctors, mostly neurologists and paediatricians, in some hospitals are able to offer a prescription for a trial period. Those eligible are expected to be mainly children.

Do you think CBD oil could be prescribed for other conditions in the future?

Numerous medications initially used in a condition were later found to be effective for a different disease. For example, carbenoxolone used to be prescribed for indigestion is now under assessment for epilepsy. CBS may also have additional benefits, at present amongst others Parkinson’s disease and pancreatic cancer are under assessment.