Medicinal Cannabinoids explained

Discover the history of medicinal cannabis, what CBD and THC are and learn about the endocannabinoid system in our bodies.

An old Parke Davis Cannabis medicine. At one time the company listed 27 different medical cannabis products in its catalogue.

What is cannabis?

Cannabis is a plant widely used in history for purposes including fibre, food and medicine. The medical use of cannabis ceased worldwide in the early 20th century with the plant listed in the UN Single Convention on Narcotic Drugs for tight control. The rediscovery of the medical use of cannabis from the latter 20th century is now reflected in its increasing legal use in countries around the world.

The entire plant can be used for a variety of purposes but it is the flowers that contain the highest concentration of the plants chemically active compounds which are called cannabinoids (usually phyto-cannabinoids to distinguish them from the endo-cannabinoids we produce in our bodies).

You probably already know of at least one: delta-9 tetrahydrocannabinol or THC for short, which is best known for its euphoric and intoxicating effects. However the one getting most of the attention at the moment in New Zealand is Cannabidiol or CBD. There are hundreds of compounds in the cannabis plant and over 100 known cannabinoids. Then there are hundreds of compounds called terpenes and flavonoids which means that each chemovar (or strain) of cannabis has a distinct chemical profile.

What is medicinal cannabis?

Cannabis for medical use is not a new concept. Cannabis was first used by the Chinese around 6,000 years ago and was used as the first recorded anaesthetic. In fact the Chinese term for anaesthesia literally means “cannabis intoxication”. Cannabis was used as a western medicine too. In fact until single molecule pharmaceuticals came to the fore in the 1960s it was common for pharmaceutical companies to list cannabis medicines in their catalogues.

Modern use of cannabis as a medicine is still in its infancy since until recently its use was banned or severely restricted in most countries. This means that we still lack some of the data we would normally expect to have for a compound designed for use as a medicine. Despite this there are already many manufacturers of medical grade cannabis products.

Some manufacturers are already using what is called good manufacturing practices or GMP meaning that the products are produced to the same exacting standards as any other medicine. So far there are a few actual medicines available that are either synthetic compounds or extracts from the cannabis plant containing THC, CBD or a combination of both.

Doctors in New Zealand can prescribe CBD products and products containing THC. All products must either be approved medicines or assessed as meeting the minimum quality standard by the Medical Cannabis Scheme. It is possible for a doctor to import a product not meeting the standard for a specific patient if they believe the verified products don’t meet their patient’s needs.

CBD explained

Interest in medicinal cannabis is growing rapidly as more people become aware of the potential benefits of CBD, the non-intoxicating cannabinoid.

To the untrained eye, the chemical structure of CBD looks remarkably similar to that of THC but there is an important difference in how they act in our bodies. CBD is not intoxicating meaning it doesn’t alter our perception or consciousness. You can’t get high from CBD but nevertheless there are a number of interesting uses for the product that are being studied.

There are already medicines containing CBD indicated for multiple sclerosis and epilepsy (the latter not in New Zealand) and some evidence that it can be beneficial in treating the symptoms of chronic pain, multiple sclerosis, epilepsy and a host of other areas ranging from anxiety to weight loss.

The reason that CBD has so much potential in so many conditions is because we have a endocannabinoid system in our bodies designed to interact with cannabinoids that affect many areas of our health. More research is needed and many studies are underway.

THC explained

THC is the primary psychoactive component of cannabis.

Delta-9-tetrahydrocannabinol (THC) is probably the best known component of cannabis and possesses psychoactive effects. For this reason it remains a class B1 controlled drug in New Zealand. It is a component (along with CBD) in a product approved in New Zealand for the treatment of some symptoms of multiple sclerosis. In some countries there are synthetic versions of THC which are used as medicines for specific uses (e.g as an appetite stimulant in patients with AIDs or an anti-nausea treatment for people receiving chemotherapy).

There is the potential for further medical uses for THC but these are countered by some of the known undesirable effects associated with cannabis and THC in particular. These include:

Potential for Dependence
Impairment of short-term memory, motor coordination and altered judgement
Cognitive impairment
Risk of mental illness

Multiple Sclerosis NZ has commissioned a report which summarises some of these effects and some strategies to mitigate them.

Endocannabinoid system

The endocannabinoid system (ECS) is a signalling system with a network of receptors through our bodies and brains.

ECS overview

The discovery of the ECS is quite recent dating only from 1989. The fact we have an ECS system helps explain both why and how cannabinoids can have effects on our bodies and health.

The ECS contains a vast network of receptors called CB1 and CB2 throughout the brain, central nervous and immune system, which act like locks on the surface of cells waiting to be acted on by chemicals called endocannabinoids (endo meaning within the body).

We produce our own cannabinoids which act on the receptors as do the plant based or phyto-cannabinoids that are in medical cannabis. The ECS plays a major role in the regulation of many physiological processes.

Some of these include our responses to pain, sleep, inflammation and memory. The fact that the ECS plays a role in so many systems helps explain the wide range of potential uses that CBD is being researched in.

CBD and our ECS

Cannabinoids produce their effects by binding to CB1 or 2 receptors or partly blocking their activity. CB1 receptors are found mostly in the brain and central nervous system whilst CB2 receptors are found mainly in the organs.

THC appears to activate both CB1 and CB2 receptors whereas the action of CBD is more complex. CBD does not bind very strongly to either receptor and can work to block receptor activity instead.

CBD also appears to be able to modulate several other receptors and ion channels and can also act through a variety of receptor independent pathways that involve delaying re-uptake of neurotransmitters and enhancing or inhibiting the binding action of other receptors.

Now Discover the potential medical uses of Cannabinoids