Can you overdose on weed or marijuana? Learn about the risks of using too much of the drug and whether a marijuana overdose is possible. Synthetic cannabinoids have caused a large number of emergency presentations to hospitals for adverse cardiovascular events including numerous deaths, particularly for the more potent analogs acting on the CB<sub>1</sub> receptor. While smoked cannabis use is often associated with significant change … Car Crash Deaths Involving Cannabis on the Rise Between 2000 and 2018, the percentage of car crash deaths in the United States involving cannabis have doubled—and the percentage of deaths
Can You Overdose on Marijuana?
The Answer Isn’t Entirely Clear, But Using Weed Has Risks
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.
Verywell Mind articles are reviewed by board-certified physicians and mental healthcare professionals. Medical Reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more.
Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital.
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Though marijuana overdose is rare, it is possible to take too much of the drug and experience adverse reactions that require hospitalization. However, the effects of a marijuana overdose are usually less detrimental than the effects of overdosing on other commonly misused drugs, such as opioids.
Risks of Marijuana Overdose
The potential risks of using too much marijuana include:
- Anxiety or panic attacks
- Heart arrhythmia (irregular heartbeat)
- Nausea or vomiting
- Paranoia or psychosis
Learn more about the negative health effects linked with overdosing on marijuana.
Marijuana (also often called weed or cannabis) doesn’t come with a clear definition of overdose. Doctors aren’t entirely sure how much tetrahydrocannabinol (THC) it takes to overdose. THC is the ingredient in marijuana most likely to induce the high that some people are seeking.
THC is the psychoactive ingredient found in marijuana. When someone experiences a marijuana overdose, it is technically a THC overdose. THC causes symptoms like anxiety, paranoia, psychosis, and in some cases, hallucinations.
A toxic level of THC, or an amount that causes severe effects, is generally considered 7.5mg or more.
Risk of Death
Some wonder if marijuana overdose can cause death. There have been a few isolated case reports where marijuana has been implicated in a death.
However, a clear causal relationship has not been established. Medical professionals aren’t sure whether those cases had other contributing factors (like pre-existing cardiac conditions).
Other Adverse Effects
Marijuana is a strange drug in that it contains a lot of active ingredients. Although scientists cite different numbers, in addition to THC, there are thought to be over 100 other cannabinoids in cannabis. Not all of these act the same way.
Get too much THC and you may have a psychoactive reaction that is not unlike that of a stimulant. Cannabidiol (CBD) is associated more with sedative effects.
The effects of marijuana use can vary widely. There have been cases of heart arrhythmias and sudden cardiac arrest while smoking weed. There are reports of both seizures and the reduction of seizures, which seems to be based on which type of cannabinoid and at what amounts are used.
Here are some examples of THC toxicity that have been published:
- Heart arrhythmias: Some doctors believe that heart disturbances are under-reported in marijuana use. Since smoking weed and taking other drugs often go together, it’s really hard to isolate the cause when the heart starts doing crazy things. Even drinking alcohol intensifies the effects, which means you can’t say for sure whether it was the pot or the booze that caused a problem.
- Psychosis or paranoia: There have been some reports of severe psychotic episodes with hallucinations and negative associations. In some cases, the psychosis can last significantly longer than the amount of time it should take to metabolize the THC.
- Uncontrollable vomiting: Although THC often has anti-nausea properties, it can rarely be associated with a syndrome of persistent vomiting. More often associated with chronic cannabis use, uncontrollable vomiting is sometimes relieved with a hot shower.
Even the method of consumption makes a difference. For example, a person may consume too much THC in edible form because it takes longer to see an effect. If one brownie doesn’t work, they take another. and maybe just one more. Suddenly, they have a serious reaction.
THC that is consumed in edible form is metabolized differently than when it’s inhaled. It takes longer to absorb THC in edibles, which can lead to to someone thinking they didn’t get enough.
Edibles are also much more prone to accidental overdoses. Smoking marijuana doesn’t usually happen accidentally. But with an edible, someone may consume a candy or brownie without realizing it contains THC.
Marijuana Overdose in Children
Kids are especially likely to accidentally consume an edible containing THC, since these often look like regular candy that kids might want to try. Edibles are often meant to be consumed in very small doses (like 1/4 of a gummy), but of course, kids aren’t aware of that; and their smaller body size also leaves them vulnerable to over-consuming.
Children presenting to the emergency department with accidental ingestion of marijuana becomes increasingly common in every state that legalizes marijuana for recreational use.
If you or your child are experiencing the signs of a marijuana overdose, call 911 or seek emergency medical treatment immediately.
Increased Concerns About Overdose
There are several reasons that medical and health experts have become concerned about the potential for marijuana overdose and adverse effects.
Increased Marijuana Use
Marijuana has been available for medicinal use since 1996 when California legalized it. Now, California, Alaska, Colorado, Maine, Massachusetts, Michigan, Nevada, Vermont, Washington, and Washington D.C. allow recreational use. In Oregon, the number of dispensaries doubled after recreational weed was legalized.
As the momentum of recreational pot builds across the country, many in the medical world report being a bit surprised by the marked increase in marijuana use in states where it has been legalized. All that new consumption has led to significant increases in marijuana-induced emergency department visits.
Increased THC Concentration
Just as modern farmers are able to get much bigger yields from crops like corn and beans, weed farmers today are much more successful than they were in the past. The levels of THC in marijuana are well above what they were before the current farmers were born.
The concentrations of THC increased from 3.4% in 1993 to 8.8% in 2008. Some folks say that just means you don’t have to roll the blunts as fat as you used to, but let’s face it: When you’re chasing the high, the bar just keeps getting higher.
How Long Does Weed Stay in Your System?
How long weed stays in your system mostly depends on how much of the drug you’ve used. If you chronically use marijuana, it can be detected in urine for 30 days or longer once you stop using it.
If you used marijuana once (and you don’t typically use it), it can be detected in urine for up to 72 hours.
How to Stop Feeling High
If you’ve used marijuana and you want to stop feeling the high, you’ll need to wait it out. But there are some things you can do in the meantime to self-soothe like relaxing, hydrating, eating, or walking.
There’s no instant cure for a marijuana high, but to calm down any anxiety or racing thoughts you might have, try deep breathing, watching a soothing video, or listening to calming music to distract yourself. You might even call a friend who can help keep you calm until the effects wear off.
Drinking plenty of water is always a good idea, especially to prevent dry mouth that marijuana often causes. Though eating isn’t proven to reduce a marijuana high, there is anecdotal evidence that carb-heavy and nutrient-dense foods make some people feel less high.
Some research supports using cannabidiol (CBD) to promote relaxation and reduce the psychoactive effects of THC. It’s recommended you check with a doctor before using any supplement or at least start with a low dosage of CBD until you know how it affects you.
Treatment for Weed Overdose
If you are hospitalized with marijuana intoxication, you may be kept overnight for 24-hour observation. You may also receive fluids intravenously (through an IV) if you’re showing signs of dehydration.
Depending on the severity of your symptoms, you may be administered a benzodiazepine to lessen anxiety or an antipsychotic to reduce psychosis.
If you’ve developed cannabinoid hyperemesis syndrome, a condition that leads to bouts of repeated vomiting in people who chronically use marijuana, a doctor can treat this with IV fluids, medication to reduce vomiting, and/or proton-pump inhibitors, which reduce stomach inflammation. It should take 24 to 48 hours to recover from cannabinoid hyperemesis syndrome as long as you stop using cannabis.
If your marijuana intoxication is linked with cannabis use disorder, a doctor may recommend that you attend an inpatient or outpatient rehabilitation program to address your condition. Rehabilitation programs often involve group therapy and educational sessions where you’ll learn how to use healthy coping mechanisms instead of turning to drugs or alcohol.
A Word From Verywell
Marijuana overdose is still a debated topic and there isn’t really a clear answer on how much pot is too much. Until there is, it’s important to be diligent if you choose to use and to keep yourself informed. Don’t accept the mantra that weed is natural and therefore, safe. What makes anything safe is an informed consumer and a critical mind.
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rod Brouhard, EMT-P
Rod Brouhard is an emergency medical technician paramedic (EMT-P), journalist, educator, and advocate for emergency medical service providers and patients.
Cannabis as a cause of death: A review
Synthetic cannabinoids have caused a large number of emergency presentations to hospitals for adverse cardiovascular events including numerous deaths, particularly for the more potent analogs acting on the CB1 receptor. While smoked cannabis use is often associated with significant changes in heart rate and cardiac output, amongst other physiological changes, it has been rarely considered in the forensic literature as a significant contributory or causal factor in sudden unexpected death. A review of case reports of admissions to hospitals for cardiovascular events was undertaken together with a review of epidemiological studies, and case reports of sudden death attributed, at least in part, to use of this drug. These publications show that use of cannabis is not without its risks of occasional serious medical emergencies and sudden death, with reports of at least 35 persons presenting with significant cardiovascular emergencies who had recently smoked a cannabis preparation. At least 13 deaths from a cardiovascular mechanism have been reported from use of this drug which is very likely to be an under-estimate of the true incidence of its contribution to sudden death. In addition, many cases of stroke and vascular arteritis have also been reported with the latter often involving a limb amputation. While it is a drug with widespread usage among the community with relatively few deaths when faced with a circumstance of very recent use (within a few hours), a positive blood concentration of THC and a possible cardiac-related or cerebrovascular cause of death this drug should be considered, at least, a contributory cause of death in cases of sudden or unexpected death.
Keywords: Arrhythmias; Cardiovascular disease; Forensic; Heart disease; Myocardial infarction; Stroke.
Copyright © 2019 Elsevier B.V. All rights reserved.
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Car Crash Deaths Involving Cannabis on the Rise
Between 2000 and 2018, the percentage of car crash deaths in the United States involving cannabis have doubled—and the percentage of deaths involving both cannabis and alcohol have more than doubled, according to a new study by a School of Public Health researcher.
Researchers from the School of Public Health, the School of Medicine, Boston Medical Center, and University of Victoria found that people who died in crashes involving cannabis had 50 percent greater odds of also having alcohol in their system.
Published in the American Journal of Public Health, these findings suggest that as states have loosened cannabis policies, cannabis and alcohol have increasingly been used together when driving.
Although the proportion of crash deaths involving alcohol has remained relatively constant over the last two decades, the proportion of crash deaths involving other substances, particularly cannabis, has increased, and little attention has been given to the connection between alcohol and cannabis use. Some have proposed that liberalizing cannabis policies could lead to a reduction in alcohol use, as individuals might substitute cannabis for alcohol. However, this study suggests the opposite—that cannabis and alcohol are increasingly being used together when it comes to impaired driving, and that cannabis increases the likelihood of alcohol use in crash deaths.
“There has been progress in reducing deaths from alcohol-impaired driving, but our study suggests that cannabis involvement might be undercutting these public health efforts,” says study senior author Timothy Naimi, adjunct professor at the Schools of Public Health and Medicine, and director of the Canadian Institute of Substance Use Research in Victoria, Canada. Currently, almost 40 percent of crash deaths in the US involve alcohol, and 30 percent of deaths involve alcohol above the legal limit for driving.
For the study, which was funded by the National Institute on Alcohol Abuse and Alcoholism, researchers analyzed 19 years of data from the Fatality Analysis Reporting System, a national database of fatal crashes on public roads. The percent of crash deaths involving cannabis more than doubled from 9 percent in 2000 to 21.5 percent in 2018, and the percent of deaths involving cannabis and alcohol also more than doubled from 4.8 percent to 10.3 percent. Cannabis was a risk factor for alcohol co-involvement, even at levels below the legal limit.
These results also show that cannabis-involved car crashes are more likely to involve the deaths of passengers as well as individuals younger than 35, compared to crash deaths not involving cannabis. A series of analyses were conducted to account for drug testing rates and alcohol policies, and the results remained consistent.
“Our testing methods for cannabis remain suboptimal and individuals can test positive for cannabis weeks after they have consumed it,” says study lead author Marlene Lira, an epidemiologist at BMC. “However, we can say that fatalities from crashes involving cannabis are more likely to have also involved alcohol, even if we don’t know the exact level of cannabis.” Most cannabis tests do not distinguish between any past use and acute intoxication, and implementing standardized thresholds is challenging due to tolerance from regular use.
”The bottom line is that we have a lot of work to do to reduce deaths and harms from impaired driving from alcohol, cannabis, and other substances,” says Lira.
In 2018, National Highway Traffic Safety Administration (NHTSA) began workgroups to mitigate the harms of drug-impaired driving in the midst of the overdose epidemic and cannabis legalization. NHTSA also commissioned the National Academies of Sciences, Engineering and Medicine to study alcohol-impaired driving whose report included the recommendation to reduce the legal alcohol limit to 0.05 percent, among other interventions. This study underscores that now, more than ever, these efforts are still needed.