London’s first medical cannabis clinic to offer the drug to children will open this week.

The Sapphire Medical Clinic in Harley Street announced it can prescribe medicinal cannabis for “all conditions acknowledged to benefit from it”.

Patients can be prescribed medicinal cannabis by specialist doctors in the UK as of November 2018.

Sapphire pain specialist Dr Michael Platt told the Evening Standard they were conscious of controversy around cannabis products with THC, but there is anecdotal evidence it has had a “strong positive impact on the children concerned”.

He said: “As part of our portfolio of services we are prepared to offer evaluative consultations to families with children affected by intractable epilepsy for consideration of cannabis-based products for medicinal use.

“Our paediatric neurology service will offer consultations to the families of the children… with an open mind but would reserve the right not to prescribe medicinal cannabis containing THC.”

UK medical experts now have the option to legally issue prescriptions for cannabis-based medicines if they think it could help their patient.

The UK law change came soon after the highly publicised case of severely epileptic teenager Billy Caldwell.

The boy fell ill when the UK Home Office confiscated cannabis oil he had been prescribed abroad.

His mother said his condition improved thanks to cannabis oil treatments.

Therapeutic value

Before the ruling, almost all cannabis-based medicinal products were judged to have no therapeutic value.

GPs cannot make the decision to prescribe these unlicensed medicines – only specialist doctors in fields like neurology or paediatrics.

They must make decisions on prescribing cannabis-based products for medicinal use on a case-by-case basis, and only when the patient has a special clinical need that is not met by licensed products.

The new law will not limit the types of conditions that can be considered for treatment and doctors will no longer need to seek approval from an expert panel for patients to access the medicines.

Researchers have found that medical marijuana is effective for pain control and conditions like multiple sclerosis, Parkinson’s disease, fibromyalgia, endometriosis, and interstitial cystitis.