Medical marijuana in children

DR ZAFIR W LATCHAN

MEDICAL MARIJUANA is a smoking hot topic of our times (pun intended). It is on the lips and minds of many individuals in TT and across the globe. There are several countries that have legalised marijuana including Canada, Germany, Israel, Netherlands and several states in the US. Some nations have legalised both recreational and medical usage while others have opted to only legalise the medical use of marijuana. In the UK, for example, it is legal for only certain medical conditions with strict conditions.

There has been a lot of hype surrounding its use in children, especially in cases of epilepsy, as can be seen by the “success stories” shared by parents online. Recently, I was privileged to attend a research conference organised by the TT Medical Association in conjunction with the Paediatric Society of TT, and it was not a surprise that one of the presentations focused on medical marijuana in children. Today, I share briefly some information that exists on this topic.

I must preface this discussion with the fact that marijuana is still illegal in TT, both for recreational and medical use, and the purpose of this article is not to agitate for or against its legalisation, but to look at what are the conditions in which it is being used in children.

The world is a small village and with the ease of communication and transportation it is possible that this treatment will be sought by parents, in places where it is legal to access. Therefore, physicians should be aware of what is the current climate of this drug in the paediatric world.

The way how marijuana works is not completely understood. We know about certain receptors in the central nervous system that are affected by marijuana, but its full mechanism of action is not known. The marijuana plant can produce up to 144 chemicals. However, there are two primary components of marijuana which are widely studied in the literature. These are: tetrahydrocannabinol (THC) and cannabidiol (CBD).

THC is considered to have the euphoric and psychotropic (mind-altering) effect while the CBD component does not cause such feelings of being “high.” The CBD component is the one that is being focused on in children.

Because of our limited evidence of marijuana usage in paediatrics, CBD usage is highly restricted at the moment. The current indications for medical marijuana in children are for severe intractable seizures (seizures that do not respond to any treatment) or as an adjunctive therapy in patients with drug resistant epilepsy (DRE).

According to the International League Against Epilepsy, DRE refers to failure of adequate trials of two tolerated, appropriately chosen and used anti-epileptic drug schedules to achieve seizure freedom.

The two main conditions in which epidiolex (which is a highly purified CBD component) is studied, and FDA approved as of June 2018, in children over the age of two years are:

1. Dravet Syndrome

2. Lennox Gastaut Syndrome

It is important to note that these conditions are very rare (between one in 20,000 to one in 40,000 for Dravet Syndrome). These patients can suffer from dozens of different seizure types and are usually unresponsive to typical first-line anti-epileptic therapy. They need constant supervision due to seizure risk and can have intellectual delays. As a result, it is understandable why a parent would seek any form of treatment available that they think will help reduce their child’s seizures and improve their quality of life.

At the same time, it must be borne in mind that CBD is not the panacea for DRE. The current evidence estimates that the number of people needed to be treated with CBD for one person to achieve a 50 per cent reduction in seizures is eight. Put another way, for every eight children who meet the criteria to receive CBD and are treated with CBD, only one will achieve more than 50 per cent reduction in seizures.

Additionally, parents and caregivers must not feel that CBD is their only option in these “hard-to-treat” epilepsy syndromes. There are other treatments such as: ketogenic diets, epilepsy brain surgery and vagal nerve stimulation. In fact, the British Paediatric Neurology Association (BPNA) issued a statement in October 2018 recommending CBD to be used only as a last resort, after other modalities have been exhausted. The BPNA stated:

“Prescription of a non-licensed cannabis-based product for medicinal use should be used as a treatment of last resort for children who meet the following three criteria:

“1. Have an epilepsy that has proven intractable to treatment with conventional licensed anti-epileptic drugs given at therapeutic doses.

“2. Have not responded to the ketogenic diet or for whom the diet is inappropriate.

“3. Are not candidates for epilepsy surgery.”

Having looked at its uses, we should also examine its harms. Medical marijuana is not without risks. There are side-effects and drug interactions. Some of the documented side-effects of CBD in the studies done on children with Dravet Syndrome include: somnolence (36%), diarrhoea (31%), decreased appetite (28%), fatigue (20%), vomiting (15%), fever (15%), lethargy (13%), upper respiratory tract infection (11%), convulsion (11%), elevated liver aminotransferase enzymes (20%), and status epilepticus (4.9%).

Additionally, CBD can interact negatively with other drugs such as valproate and clobazam. Another negativity that should be considered is the rise in marijuana toxicity and addiction in children living in places that have legalised recreational and medical marijuana.

While we know that chronic recreational use of THC can affect the developing adolescent brain, we await long-term studies on the effects of chronic medical usage of CBD. At the present moment, CBD has its potential uses specifically in children with Dravet and Lennox Gastaut Syndrome. At the same time, CBD is not the panacea for these children. It has side-effects and there are alternatives to be explored.

Medical marijuana and its use in children is certainly something that will not go away. In the next 20 years I reckon we would have more evidence to make an informed decision. As for now, it is our job as physicians, parents and paediatricians to follow the developments and keep up to date, as the use of it will likely progress as the evidence base becomes stronger.

Dr Zafir W Latchan is a paediatrician at Marabella Paediatric Services

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Medical marijuana, which comes in a variety of forms, and its use in children is certainly something that will not go away.