Sun | Jan 17, 2021

Ounce of Prevention | Cannabis - A most versatile medicinal plant

Published:Monday | November 6, 2017 | 12:00 AM

Plants have been the predominant source of medicines throughout much of human history, and this remains true in many non-industrialised societies. Cannabis is one of the most versatile of medicinal plants. It has led scientist to discover a powerful and unique regulatory system in the body called the endocannabinoid system (ECS).

Without getting too technical, consider this: The ECS is extremely active throughout the entire body, especially the nervous system and the immune system, and it produces its own cannabis-like substances called endocannabinoids. Yes, your body creates its own forms of ganja, and virtually all of your cells are influenced by them.

Scientists have identified over 100 active compounds in the natural ganja plant called phytocannabinoids. Delta-9 Tetrahydrocannabinol (THC) is the best known of these, followed by Cannabinodiol (CBD). They mimic the activity of the body's own endocannabinoids.

While it seems that most of the psychoactive or mind-altering properties and some of the medicinal usage comes from THC, it is also clear that CBD has several important medical usages. There are many interactions between these chemicals, and scientists are now able to prepare medicines with cannabis that have powerful medicinal benefits without creating a'high'. This, in essence, is what medicinal cannabis is.

Though still beset with numerous regulatory restrictions, cannabis is currently used as a therapeutic agent in many countries and has been documented by various medical and government bodies worldwide to have the following general effects:

- Increased feeling of well-being

- Heightened sociability

- Muscle relaxation

- Analgesic effect

- Appetite stimulation

- Antiemetic effect

- Anticonvulsant effect

- Decreases intraocular pressure.




Several expert bodies have sought to evaluate the available scientific evidence for the use of medical cannabis.

One such recent review in 2016 at the request of the Parliamentary Group for Drug Policy Reform in the United Kingdom reported the following:

- Good evidence for cannabis products or 'natural cannabis' in the management of chronic pain, including neuropathic pain, spasticity, nausea and vomiting, particularly after chemotherapy, and in the management of anxiety.

- Moderate evidence in sleep disorders, appetite stimulation after cancer chemotherapy, fibromyalgia; PTSD, and symptoms of Parkinson's disease.

- Limited evidence and more research required in conditions such as cancer control, epilepsy, neurological conditions, glaucoma, and mental illnesses.

It was noted that much more research needs to be done. On the other hand, there is a larger body of case reports and anecdotal evidence of therapeutic benefits from cannabis in those and other conditions like migraine, chronic fatigue syndrome, irritable bowel syndrome, and endometriosis.




Here in Jamaica, the Ministry of Health, along with the Medical Association of Jamaica, has been training and registering doctors to prescribe and treat patients with cannabis products. Anyone interested in using medicinal cannabis should consult a doctor who has been so trained and registered.

When medicinal cannabis treatment is being considered for a patient, it is essential that an accurate and thorough assessment be done by the medical practitioner.

This should include:

- Presenting symptoms, past medical history, psychological and psychiatric history, and family history of mental illness.

- Social history: family support for the use of medicinal cannabis; family responsibilities such as caring for young children; work issues; especially where it involves driving or operating machinery; risk of falls in older patients.

A physical examination and investigations and a review of the use of any other medication is also advised.


Medical products


A variety of cannabis-based products have been developed for both topical and internal use here in Jamaica and abroad. Dr Henry Lowe and his team at Medicanja must be congratulated for the fine research they have done to bring to the Jamaican public an impressive array of cannabis products for medicinal use. These can be applied to the skin as alcohol-based rubs, creams, sprays or oils, or ingested as sublingual or oro-mucosal sprays.

Cannabis can also be introduced via the lungs by vaporisers, steam inhalations or by smoking. All medical authorities have strongly advised that medicinal cannabis should not be administered by smoking.

Inhaling cannabis leads to a very rapid onset of effect (within minutes), with a peak effect after 30 minutes. The duration of effect extends for two to four hours. Smoking is not recommended as a delivery system for medicinal cannabis.

Ingesting cannabis results in a slower onset of effect over 30 minutes.

The effects are more progressive and prolonged eight hours or more. There is also need for special care to be exercised in the use of cannabis in the young as the developing brain is particularly sensitive to the cannabinoids.


Adverse effects


Starting at the lowest possible dose and increasing slowly over days to weeks until a satisfactory result is reached will minimise the risk of side effects. The maxim is "start low and go slow".

The possible side effects of cannabis are usually dose related and include: disorientation, dizziness, poor coordination, agitation, anxiety, rapid heart rate, dry mouth, sleepiness, low blood pressure, euphoria, hallucinations, and rarely, psychosis (usually among predisposed individuals).

- You may email Dr Vendryes at or listen to An Ounce of Prevention on POWER106FM on Fridays at 9:00p.m. Visit for details on his books and articles.