Cannabis use is not harmless, and overdose is possible. Cannabis may cause anxiety, paranoia, delusions or hallucinations, rapid heart rate, increased blood pressure, and severe nausea or vomiting. Some forms of cannabis use have a greater potential for poisoning due to the varying effects they can have on the body compared to smoking cannabis. Edibles and drinks infused with cannabis often contain unknown amounts of tetrahydrocannabinol (THC), can produce delayed effects, or have intoxicating effects that take longer than expected (CDC, 2021).
Those who experience potential cannabis poisoning or other poisoning should seek help by calling the 24/7 National Poison Control Hotline or by visiting their website at poison.org. Both options provide free, expert, and confidential guidance in a poison emergency. Calls will be routed to the local Poison Center, and will be managed by a Poison Specialist (registered nurse or pharmacist) who will determine the severity of your case and provide recommendations.
From 2016-2022, there was a total of 110,532 cases that mentioned cannabis as an exposure in Poison Control Center calls. The annual number of cannabis-related calls increased from 7,503 cases in 2016 to 27,766 cases in 2022.
From 2016-2022, there were 68,426 cases in which cannabis was reported as the single source of exposure and that did not involve any other substance. The number of single exposure cannabis cases reported increased from 2,951 (39.3%) cases in 2016 to 19,972 (71.9%) cases in 2022 (Figure 1).
Cannabis accounted for 0.5% of all single exposure cases in humans that were reported to the National Poison Control Center.
Dried cannabis plants were the most common type of cannabis exposure mentioned in Poison Control cases in 2016 to 2020, but were surpassed by cannabis edibles in 2021. Poison Control cases mentioning edibles continued to rise by 53% the following year (Figure 2).
Consumption of edibles carries a greater risk of poisoning than smoked cannabis. Ingested cannabis produces a delayed effect, which can lead some people to consume more before starting to feel the effects. The effects can last longer than expected, depending on the amount ingested, the last food eaten, and medications or alcohol used at the same time. The effects can also be unpredictable since the concentration of tetrahydrocannabinol (THC) is very difficult to measure and is often unknown in edible products (CDC).
In 2022, cannabis edibles were mostly (89.6%) reported alone as a single exposure, followed by cannabidiol (CBD, 84.5%), vapes (78.6%), and cannabis concentrates such as oils and tinctures (76.5%). Poison Control cases involving cannabis dried plants as the single exposure (46.8%) were less common (Figure 3), and often tended to also involve other substances.
Among Poison Control cases that reported a single cannabis exposure, those involving edibles have increased substantially in recent years, surpassing dried plants in 2019 to become the most common cannabis exposure type. Reports of cannabis edibles single exposures grew from 19 cases in 2016 to 10,512 in 2022 (Figure 4).
Annually, about half of the Poison Control cases relating to cannabis edibles were among children aged under 13 years, with the yearly percent increasing from 47% in 2017 to 60% in 2022 (Figure 5).
From 2016-2022, the number of calls mentioning cannabis edibles exposure immensely increased for all ages, particularly for young children aged 5 and under, increasing from 7 cases in 2016 to 4,301 cases in 2022.
Cannabis edibles are more likely to be mistaken by children and adults as regular food and candy, leading to accidental consumption (CDC, 2020).
In 2022, over a quarter (27.3%) of single cannabis exposure cases resulted in moderate or major health outcomes (Figure 6).
In 2016-2022, there were a total of 45,172 cases treated in a health care facility for cannabis when it was the only exposure. Single cannabis exposure cases who received treatment at health care facilities increased 549% from 2,081 in 2016 to 13,500 in 2022 (Figure 7).
In California, following the legalization of recreational use of cannabis in 2016, the number of calls made to the Poison Control Center hotline for help on cannabis exposure had increased 155% from 2016 to 2022. In 2022, there was an annual total of 2,169 calls made for cannabis exposure (Figure 8). In 2021, cannabis exposures accounted for 3.7% of all drug-related calls (N=3,099) in LAC (NDEWS).
A growing number of cannabis-related calls to the California Poison Control Center have involved unintentional exposures to cannabis. From 2016-2022, calls for unintentional exposure increased 329% from 296 to 1,271. Calls for unintentional exposures surpassed intentional exposures in 2020, and accounted for 59% of cannabis-related calls by 2022 (Figure 9).
Similar to the national trend, cannabis edibles have been the exposure type most frequently mentioned in calls to the California Poison Control Center, surpassing call mentions for dried plants in 2019.
The total number of calls mentioning cannabis edibles increased considerably from 4 in 2016 to 1,175 in 2022. In 2022, 54% of calls to California Poison Control Center mentioned cannabis edibles (Figure 10).
Adults aged 20 and older accounted for the largest proportion of calls for cannabis-related exposures in 2016-2020. However, cannabis-related calls among children aged 5 and under had been increasing over this time, and surpassed those of adults in 2021 and 2022 (Figure 11).
In 2016-2022, while cannabis-related calls were usually for intentional exposure among youth aged 6-19 (58%) and adults aged 20+ (57%), nearly all (99.5%) calls made for children aged 5 and under were for unintentional exposure of cannabis.
Cannabis edibles have increasingly become the most common type of cannabis exposure reported to California Poison Control Center. From 2016-2022, cannabis-related calls increased 445% among children aged 5 and under, and increased 150% in those aged 6-19. In 2022, children aged 5 and under accounted for 43% (n=502) of all cannabis-edible exposure calls (Figure 12).
From 2016 to 2022, cannabis-related Poison Control calls increased by 176% for females (395 to 1,090) and by 135% for males (454 to 1,067).
In 2022, for the first time, there were more cannabis-related calls for females than males (Figure 13).
American Association of Poison control Centers National Poison Data System (NPDS). 2016-2022 Annual Report of the National Poison Data System©. https://www.poisoncenters.org/annual-reports.
California Department of Public Health (CDPH), Substance and Addiction Prevention Branch. Cannabis Poison Control System Calls Dashboard [online]. 2023. Accessed Aug 21, 2024. https://www.cdph.ca.gov/Programs/CCDPHP/sapb/cannabis/Pages/Cannabis-Poison-Control-System-Calls-Dashboard.aspx
National Drug Early Warning System (2022). National Drug Early Warning System (NDEWS) Summary Report for 2021: Results from Sentinel Site Surveillance (NDEWS-2022-AR0001). https://ndews.org.