What is marijuana?

Marijuana refers to the dried components of the cannabis plant – hemp flower, leaves or seeds. The cannabis plant contains more than 100 compounds (or cannabinoids). Some compounds like tetrahydrocannabinol (THC) are “impairing” meaning they could cause a “high”, whereas others such as cannabidiol (CBD), are not mind-altering.

Marijuana can be used in a number of ways. The most common ones are:

· Smoked in cigarettes (joints) or pipes (bongs)

· Vaped in e-cigarettes

· As edibles when mixed into foods or drinks, usually desserts or alcohol

· Dabbed, via inhaling oil concentrates.

Does marijuana affect everyone the same way?

No, as that depends on:

· Amount and frequency of marijuana use

· Previous experience with marijuana or other drugs

· Use of marijuana with other substances (eg alcohol or other drugs), which could increase the risk of a harmful effect

· Mode of use. For example edibles can have a high THC concentration causing unpredictable effects, overdose or poisoning

· Biology (genes)

· Gender (women may experience more dizziness than men).

What are the effects of marijuana on the heart?

Increased heart rate: THC can cause an increase in heart rate or tachycardia. It can last for several hours and can place additional stress on the heart, especially in people who already have coronary disease or heart failure.

Decreased blood pressure: Marijuana can cause a decrease in blood pressure, which can lead to dizziness, and in some cases fainting, especially when getting up from a sitting or a lying position. This effect can be especially pronounced in older individuals or those on blood pressure medications.

Irregular heartbeats: On occasion, marijuana use has been associated with the development of erratic heart rhythm or arrhythmia. Arrhythmias can increase the risk of sudden cardiac death, especially in people with pre-existing heart conditions.

Cardiac ischemia: Marijuana use can restrict the blow flow across the coronary vessels, increasing the risk of heart attack, especially in “newbies” to the drug.

What are the effects of marijuana on the brain?

Short-term effects: Within 24 hours of use, marijuana can have an immediate impact on thinking, attention, memory, coordination, movement, and time perception.

In the long run:

· Marijuana can affect brain development, as studies suggest that marijuana use by mothers during pregnancy (the effect on the foetus) and by children before the age of 18 years could be linked to problems with attention, memory, problem-solving skills, and behaviour.

· Compared with teens who do not use marijuana, teens who use marijuana are more likely to quit high school or not get a college degree.

· Studies have found strong associations between second-hand marijuana smoking (eg a parent, relative, or caretaker) and the child having detectable levels of THC.

· In adults, marijuana has been associated with lack of concentration, memory deficit, and long-term mental decline.

· Some studies have suggested that marijuana use may increase the risk of stroke, although more research is needed to confirm this link.

It is worth mentioning that most of the scientific studies linking marijuana to heart attacks and strokes are based on reports from people who smoked marijuana, as opposed to other ways of using it. Smoked marijuana delivers not only THC and other cannabinoids to the body, but a slew of other toxic substances present in tobacco smoke.

Is marijuana use legal?

In 2018, the US Congress passed a law that removed hemp from the federal Controlled Substances Act, effectively legalising CBD if it comes from hemp. However, a few states have not followed suit, so legality of marijuana differs across US states lines.

Is CBD a medicine?

Studies are still ongoing to further learn about how CBD affects the body. The US FDA agency approved Epidiolex, a medicine that contains purified CBD from cannabis plants, to help treat seizure disorders. The FDA has concluded that this drug, and only this one is safe. Other marketed uses of CBD are not FDA-approved.

What are synthetic cannabinoids?

Synthetic cannabinoids, also called spice, K2 … are man-made substances and, despite the name, are not marijuana or cannabinoid medicines. They are part of a group of unregulated, mind-altering drugs. Their effects are not fully understood and can cause dangerous and unpredictable health consequences, including severe chest pain and palpitations, brain swelling and seizures. They are often sprayed onto dried plant material that can then be smoked, or sold as liquids. They are illicit, not legalised for production or use.

Joseph Yammine is a consultant cardiologist at the Bermuda Hospitals Board. He is also the director of the outpatient multi-speciality clinics and director of the Cardiac Computed Tomography programme.

The information herein is not intended as medical advice nor as a substitute for professional medical opinion.