Updated on December 15, 2017.
Medical content reviewed by Dr. Joseph Rosado, MD, M.B.A, Chief Medical Officer
One of the struggles the states have with legalizing marijuana for medical purposes is regulating its use to protect public safety. The reason the FDA classified marijuana as a Schedule I drug is because there was evidence that marijuana posed a serious risk to public health. Scientific research since then has proven marijuana provides more benefits than risk, but regulations are still catching up.
While using marijuana does not pose a risk to the user, if that user drives a car, it could present a danger to passengers in that car, other vehicles on the road and the driver himself. Unlike alcohol, impairment due to cannabis cannot easily be measured with blood content, so it’s difficult to create and monitor legal limits.
Medical marijuana offers many benefits to users, who can now enjoy those benefits legally. There’s no risk of overdosing from marijuana, but it can impair your motor skills and judgement. It’s important to be aware of the risks you face as a medical marijuana user and take the necessary precautions.
Side Effects of Medical Marijuana
Although the benefits far outweigh the risks, cannabis products do produce some unwanted effects. Like any drug, effects vary from person to person, and your reaction to one strain of marijuana can also vary from others.
These are some general potential short-term side effects of marijuana use you should be aware of:
Loss of coordination or balance
Slower reaction times
Inaccurate sensory perceptions
Decrease in short-term memory
You might not consider these side effects serious for your situation. Depending on what symptoms you’re treating with cannabis and what your daily activities include, these effects could even go unnoticed. However, you should be aware of these potential side effects in case they do have an impact on your daily life.
Duration of Impairment by Marijuana Usage
Common sense tells you not to smoke marijuana while driving down the road. In addition to drawing attention to what could be considered illegal possession, you’re putting yourself in a dangerous situation. The distraction of lighting up and maintaining your smoking joint could be enough to cause an accident.
While smoking a joint, you’re feeling the maximum benefits of the cannabis, but your senses are also maximally impaired. The question remains, how long after smoking until it’s safe to drive your car? Cannabis can remain in your system for up to 30 days in a concentration strong enough to be detected by a urine test. Traces of marijuana might be found in your blood up to seven days after you smoke it, and it can be discovered with a hair test almost 90 days later.
Studies show the effects of marijuana on your motor skills and judgement can last up to six hours. There are many variables to consider in this calculation. People react to marijuana differently based on their overall health and experience using the drug. The method of administration also determines how long the effects last.
If cannabis is inhaled, either by smoking or vaporizing, its effects can usually be felt for up to three hours. When marijuana is ingested in an edible product or capsule, it takes a little longer to kick in because it passes through the digestive system. The result, however, is a longer-lasting effect. Ingested cannabis can give you up to six hours of relief.
To stay safe, you need to consider these factors when using marijuana products. Based on the type of product you use and your overall experience of feeling its effects, you can estimate how long your judgement might be impaired after taking your medical marijuana.
Restricted Activities Under the Influence of Cannabis
Even though you’re taking marijuana for medical purposes, it can still cause you harm if you allow yourself to be in unsafe situations while you are under the influence.
These are some of the activities you should avoid while your judgement and motor skills are impaired by marijuana:
Driving a motor vehicle. Decreased reaction times can make you a dangerous driver. Even a slight sense of euphoria may cause you to take unnecessary risks while driving that can result in an accident and injuries to yourself and others.
Operating heavy equipment. Even more dangerous than driving a car, operating heavy equipment while under the influence of marijuana can be deadly. In addition to slower reactions, your sensory perception can be distorted. Without an accurate sense of depth perception, you can’t operate heavy equipment safely.
Working around machinery. If your job involves any type of machinery, it’s not safe to work under the influence of marijuana — even if you don’t operate that machinery. Distorted sensory perception could cause you to injure yourself on the job.
Carrying a firearm. Working in law enforcement or another field that requires you to carry a gun is not a good idea while you’re under the influence of marijuana. In addition to impaired judgement that would obviously impact your job performance, marijuana can affect your mood. Being around firearms while you’re under the influence of any substance is not safe.
Supervising children. Good judgement and keen motor skills are essential when supervising children. When you’re under the influence of marijuana you can’t safely work with children. You might not pose a direct threat to them, but if you fall asleep or lose track of time and forget to feed the baby, for example, there could be negative consequences. Be sure there’s another adult supervising the kids while you use medical cannabis.
Swimming. Relaxing on the beach might not seem like a dangerous activity, but when you’re under the influence of marijuana, swimming is not a good idea. Marijuana impairs your judgement and causes you to take risks. You could swim out too far or get tired while swimming to an island that didn’t look that far away.
The best way to stay safe while you are taking medical cannabis is to plan. Based on your doctor’s recommendations, create a schedule for dosing that fits with your daily activities. If you work in an environment where being high could be dangerous, figure out how to schedule your marijuana treatments around your work or plan to take some time off.
Never drive while you’re under the influence of marijuana. Plan to take your medicine at home when you can remain home, with supervision if necessary, until the effects wear off. Having a routine will help you avoid making poor decisions.