Since medical cannabis was legalised in the UK in November last year, not one NHS prescription has been written for it. In fact, at the time of writing, less than a dozen prescriptions – all in the private sector – have been handed out in total.

Patients who could potentially benefit from cannabis are being denied it for a number of reasons. Firstly, there is a widespread lack of relevant education among doctors. Most have not been trained in cannabis and don’t know how to prescribe, in what dose or format. We therefore urgently need an education programme; and it’s a pity the government didn’t put one in place to correspond with last year’s law change. The only existing such training programme in the UK currently is free to all online and delivered by the Academy of Medical Cannabis.

This is a good start but more proactivity is needed from the NHS and Whitehall in educating the UK’s doctor community.

Another barrier to access is the flawed nature of certain guidelines recently issued on cannabis. Both the Royal College of Physicians’ guidelines on pain, and the British Paediatric Neurology Association’s childhood epilepsy guidelines, are extremely restrictive. The former effectively state that cannabis medicine should not be prescribed for pain, despite evidence to the contrary. The latter, meanwhile, are similarly reluctant to recommend medical cannabis.

These are just guidelines, yet many doctors are worryingly treating them as mandatory. More balanced guidelines have been published recently by the UK Medical Cannabis Clinicians Society and can be found online at ukmccs.org.

Also preventing doctors from prescribing is the fact that cannabis is an unlicensed medicine. This means that the doctor has to take total responsibility for anything that may go wrong with it – unlike licensed medicines which are the responsibility of their manufacturer. It is understandable that some doctors, especially those with limited experience in the earlier stages of their careers, may be a little reluctant to take on this responsibility.

Furthermore, some doctors feel there is there is not enough evidence for medical cannabis, which, frankly, I believe is rubbish. Efficacy for pain, epilepsy, spasticity and nausea and vomiting after chemotherapy is well evidenced. Admittedly, there is less evidence for certain other conditions – such as Parkinson’s, autism and Crohn’s – but when you’ve exhausted all other options then cannabis should at least be considered because it is so safe.

Another argument is that the long-term safety of cannabis medicine is not kown. This is nonsense; cannabis has been around as a medicine for at least 2000 years and is now used by over three million Britons every day. If there was a nasty side effect we would know by now. More randomised controlled trials would theoretically help to change the current UK situation.

However, cannabis medicine comes in so many different strains and patients often use trial and error to find the right one for their condition. We therefore need a different way to review its efficacy based on the real-world experience of tens of thousands of patients – rather than a large-scale study of one particular strain versus a placebo.

One final challenge that is preventing medical cannabis access is the lack of supply in the UK, which in turn is pushing the price of prescriptions up.

Currently, every prescription has to be imported individually, with various shipping fees attached to them.Getting more supply into the country, and making the process less bureaucratic, would bring the cost down and speed up prescriptions considerably.

Professor Mike Barnes led the first legal prescription of medical cannabis in the UK last year, for then-six-year-old Alfie Dingley, who has severe epilepsy.