A CANNABIS-BASED medicine has been approved for routine use on NHS Scotland for the first time, in a breakthrough for children with rare forms of epilepsy.

Epidyolex has been approved by the Scottish Medicines Consortium (SMC) to treat Dravet syndrome and Lennox Gastaut syndrome.

The a cannabidiol medicine will be available in combination with clobazam - an existing anticonvulsant - to patients aged two and older.

Clinical trials have shown that the combined therapy could cut the frequency of seizures by as much as two thirds.

It has been recommended for patients in England and Wales since November, with funding subsequently fast-tracked so that it could be provided to patients there from January this year.

The SMC decision brings Scotland into line with the rest of the UK, and also marks the first time that a cannabis-based medicine is being routinely paid for on NHS Scotland.

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Until now, a small number of patients were able to access the medication only through clinical trials or on compassionate grounds following case-by-case applications.

Professor Sameer Zuberi, consultant paediatric neurologist at the Royal Hospital for Children in Glasgow and and Glasgow University academic, said he had received “significant interest” from parents who had exhausted other treatment options.

He said: “This decision is significant for children, and also adults, who suffer the effects of these two severe and difficult to treat epilepsies.

“Having received significant interest from patients and their families for additional treatment options over the past few years, I am glad it will soon be available on the NHS for eligible patients in Scotland.”

Dravet syndrome is a rare and severe form of epilepsy which begins in early childhood. It is characterised by frequent and prolonged seizures and is highly resistant to existing epilepsy medicines.

Around two or three in every 500 children with epilepsy are estimated to have this form of the condition.

Lennox Gastaut syndrome usually emerges between the ages of three and five. Most children with Lennox-Gastaut have intellectual disability or learning problems even before seizures begin, but these problems may worsen over time - especially if seizures are very frequent or severe.

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Most commonly, sufferers experience 'tonic' seizures where muscles stiffen uncontrollably.

It is more often diagnosed in boys than girls, and accounts for less than five per cent of all childhood epilepsy cases.

While doctors have used cannabis derivatives to treat epilepsy since the late 19th century, researchers still do not fully understand why cannabidiol (CBD) works.

Epidiolex contains CBD but not THC - the cannabis compound which causes mind-altering effects.

It was approved through the patient and clinician engagement (PACE) process, which is used by the SMC for medicines to treat end-of-life and very rare conditions.

It is the first treatment of its type approved for routine use on NHS Scotland since the UK Government changed the law in 2018 to allow cannabis-based medicines to be prescribed.

Mark MacGregor, chair of the SMC, said: “We know from the powerful testimony given by patients and clinicians in our PACE meetings that our decisions on cannabidiol for both Lennox-Gastaut syndrome and Dravet syndrome will be welcomed, and hopefully provide some relief for patients and their families.”

The most commonly reported adverse reactions were drowsiness, decreased appetite, diarrhoea, fever, fatigue and vomiting.

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Louise Cousins, director of external affairs at the charity Epilepsy Action, said new treatment options for severe epilepsies "do not come very often”.

However, Ms Cousins said there was “still more work to do”.

She said: “Much-needed clinical trials and alternative access routes should be prioritised so that those people with epilepsy who could benefit from cannabis-based medicines can access them safely on the NHS.”

Chris Tovey, chief operating officer for manufacturer GW, said the outcome "is proof that cannabis-based medicines can successfully go through extensive randomised placebo-controlled trials and a rigorous SMC evaluation process to reach those patients in need.”