NHS England has “approved” two cannabis-based drugs for epilepsy and multiple sclerosis (MS).
Health officials recommend doctors prescribe Epidyolex for children with Lennox Gastaut or Dravet syndrome, severe forms of epilepsy that can cause multiple seizures a day.
The oral solution contains the cannabis-compound cannabidiol (CBD), which has been shown to reduce the number of seizures by up to 40% in some young patients.
And the mouth spray Sativex is being recommended for muscle stiffness and spasms in MS sufferers.
Unlike Epidyolex, Sativex contains the psychoactive compound tetrahydrocannabinol (THC), which makes drug users “high”.
Epidyolex’s recommendation comes after the National Institute for Health and Clinical Excellence (Nice), which provides guidance on drug use for the NHS, said the medication was cost effective.
It was officially approved in Europe in September, however, Nice questioned whether it was good value for money.
Epidyolex costs between £5,000 ($6,340) and £10,000 ($12,685) per patient per year.
Its manufacturer GW Pharmaceuticals has reportedly agreed a lower price with the NHS.
Epilepsy affects around one in every 200 children in the UK, Epilepsy Society statistics show.
Of these, between one and five in every 100 have Lennox-Gastaut syndrome, according to Epilepsy Action.
Dravet syndrome affects around one in every 19,000 people in the UK, Dravet Syndrome UK statistics show.
Each country within the UK makes its own decision on drug approval, the BBC reported.
Nice guidance should apply in Wales and Northern Ireland, while Scotland could follow suit next year, it added.
Dr Sushil Beri, clinical lead at Sapphire Medical Clinics - which offers medical cannabis - said: “These Nice recommendations are another sign medical cannabis is rapidly maturing as a field of medicine.
“Dravet Syndrome and Lennox Gastaut Syndrome are some of the most challenging childhood epilepsies.
“This new drug at least offers some hope for these children and their families, and an option for clinicians to consider.”
Sativex has been available in Wales on the NHS since 2014, making it the first cannabis-based drug to be licensed in the UK following clinical trials.
Also manufactured by GW Pharma, it costs around £2,000 ($2,530) per patient per year.
Regulators in England initially said it was not cost effective, however, they have since reversed their stance.
The approval decision means Sativex can only be prescribed for spasticity, not pain.
Sativex should also be available in Northern Ireland, the BBC reported.
Some experts have hailed the recommendations “great news”.
Professor Helen Cross, from Great Ormond Street Hospital - who led UK trials of Epidyolex - told the BBC: “Dravet and Lennox Gastaut syndromes are both complex difficult epilepsies with limited effective treatment options and this gives patients another option.”
However, some parents of epilepsy patients are disappointed the NHS has not approved drugs with THC.
“It is particularly devastating there is no positive recommendation that the NHS should allow prescribing of whole-plant medical cannabis containing both CBD and THC in appropriate cases of intractable childhood epilepsy,” Millie Hinton, from the campaign End Our Pain, said.
“It is this kind of whole-plant extract that has been shown to be life-transforming for a significant number of children.
“A number of the families we represent met senior Nice representatives in person only a few weeks ago.
“They explained first-hand they were paying thousands of pounds every month for private prescriptions of whole-plant extract medical cannabis and their children were showing dramatic reductions in seizure rates and equally dramatic improvements in quality of life.”
And some argue young patients with other forms of epilepsy are still missing out.
“These guidelines only recommend [Epidyolex’s] prescription for these two specific syndromes, which account for about 20% of the total population of severe childhood epilepsies and there are stringent conditions to the prescription,” Dr Beri said.
“So there is a continuing and urgent need to develop more evidence as to how medical cannabis could help across a range of other severe drug-resistant childhood epileptic conditions”.
Nice argues more research is required before cannabis-based drugs can be used for other forms of epilepsy.
End Our Pain added the “restrictive” guidelines force parents to “consider illegal sources”.
This comes after some families sourced THC-based drugs from abroad, bringing them back into the UK illegally.
Cannabis-based drugs were legalised in November last year, allowing specialist neurologists to prescribe the medication.
Reports suggest few prescriptions were doled out due to the treatments not being tested under rigorous controlled trial conditions.
Muddled prescribing guidelines and issues over funding were also blamed.
When it comes to Sativex, the MS Society is disappointed not to have a cannabis-based drug to treat pain.
“We’ve been campaigning for access to Sativex for years and it’s brilliant Nice has finally listened,” Genevieve Edwards, director of external affairs, said.
“These guidelines are an important first step, but don’t go far enough.
“No cannabis-based treatments have been recommended to treat pain, a common symptom of MS.”
Nice claims a lack of evidence means THC cannot yet be prescribed for chronic pain.
Research shows 10,000 MS patients could get pain relief from cannabis-based drugs when other treatments have failed, Ms Edwards added.