by Caislin Firth, PhD, MPH

Washington Poison Center (WPC) receives calls for help about people who used a substance and experienced negative reactions. An increase in poison center calls for cannabis consumption have been documented in legalized states since 2014.1 Given this increase and the diversification of legalized cannabis products, poison centers began collecting more information on the type of cannabis products that triggered these requests for help in 2017.

This factsheet describes the demographics and clinical severity of cases reported to WPC from 2017-2020, by cannabis product consumed and focused on people 13 years of age or older who intentionally consumed cannabis. This report does not cover unintentional, accidental use of cannabis by children under the age of 13, which has been analyzed elsewhere.2,3

Any person with a Washington state phone number who calls the national poison center hotline will be referred to WPC for consultation. Since 2017, WPC has received 739 calls for help because of intentional cannabis use; an average of 185 calls per year. The majority of calls report use of “cannabis” or “cannabis flower” (52% of all calls); 31% edibles, and 17% concentrates. Fifteen calls over the last 4 years were related to CBD products. The most common edibles were candy, drinks, and brownies, and the majority of concentrate products reported were oils and dabs.

Graph showing number of calls to WPC for plant, edible, concentrate (as described in text)
Figure 1. Intentional cannabis exposures over time by product types, Washington Poison Center, 2017-2020

Over time the number of calls for edibles has increased: by 2020 nearly the same number of calls were received for cannabis plant and edibles, an 83% increase from 2017 (Figure 1). The number of calls for concentrates increased 40% from 2017 to 2020 (from 19 to 26 cases), likely reflecting the rapid increase in cannabis concentrate sales in Washington state.4

One in every five calls involving cannabis (22%) were classified as a suspected suicide (161cases) and 98% of those calls involved at least one other substance besides cannabis. Not surprisingly, suspected suicide cases were more likely to result in moderate or major medical outcomes that required healthcare intervention (e.g., admitted to hospital or psychiatric facility) when compared to cases not involving suspected suicide.

The following analysis examines WPC cannabis cases involving voluntary use that was not classified as a suspected suicide attempt. Cannabis was the only substance consumed for roughly half of cases (49% or 281 cases)

Patterns in intentional cannabis exposure by product type and demographic groups

Gender

More poison center calls involving intentional cannabis use (2017-2020) were for males:

  • 69% of calls about using concentrates were for males
  • 62% of calls for cannabis flower were for males
  • 53% of calls for edibles were for males

Age

The age of cases ranged from 13 to 84 years old:

  • 1/3rd of calls were about underage cannabis use (<21 years old)
  • 1/2 of all calls were for cases under the age of 25
  • Calls for underage cases (13-20 years) were more likely to be for concentrates compared to older adults who could legally use cannabis (23% vs. 18% respectively)
  • Adults of legal age were more likely to call about edibles (44% of calls) compared to underage users (18%)
  • Edibles were the most common exposure for adults between 25-64 years old (Figure 2)
graph showing intentional cannabis exposures by age of patient and product type, with most calls to WPC coming from 13-17 year olds for use of the plant.
Figure 2. Intentional cannabis exposures by age of patient and product type, Washington Poison Center, 2017-2020

Who is more likely to experience moderate to major clinical effects

People who experienced moderate or major clinical effects likely needed medical intervention; 80% of calls with moderate or major clinical effects were made from health care facilities compared to 26% of calls with less severe effects.

Moderate or major cases were also more likely to involve at least one another substance that was not cannabis prior to calling poison center (58% compared to 42% among patients with less severe effects).

For those who were only exposed to cannabis, concentrate use contributed to more moderate or major clinical effects. When differences in age, gender, and year of exposure were accounted for, people who only used a concentrate product were nearly 3 times as likely to have moderate or major clinical effects when compared to those who only used cannabis flower. People who used edibles experienced moderate or major effects at a similar level as cases who used cannabis flower. In addition, age or gender were not risk factors for experiencing moderate or major effects.

Conclusions

Washington Poison Center logo with phone number 800-222-1222
  • WPC calls for intentional cannabis exposures have not increased over the past 4 years, but the number of calls for edibles has.
  • Edibles are a common exposure among middle age adults, but edible use was not associated with experiencing greater moderate or major clinical effects, which may require healthcare intervention.
  • Concentrate use did result in stronger clinical effects and their use is more common among males and underage users (13-20 years old).

This analysis of WPC data sheds light on which types of cannabis products and who may be more likely to experience more sever negative outcomes after their use. Work remains to understand how product dosing, packaging, and consumer behavior influence negative experiences and calls made to poison center.

References

  1. Shi Y, Liang D. The association between recreational cannabis commercialization and cannabis exposures reported to the US National Poison Data System. Addiction. 2020;115(10). doi:10.1111/add.15019
  2. Washington Poison Center. 2017 Annual Toxic Trend Report: Cannabis. Seattle, WA. https://www.wapc.org/wp-content/uploads/2017-Cannabis-TTRU.pdf
  3. Washington Poison Center. 2018 Annual Data Report: Cannabis. Seattle, WA. https://www.wapc.org/data/data-reports/cannabis-data-report/
  4. Firth CL, Davenport S, Smart R, Dilley JA. How high: Differences in the developments of cannabis markets in two legalized states. Int J Drug Policy. 2020;75:102611. doi:10.1016/j.drugpo.2019.102611

Citation: Firth C. Calls to Washington Poison Center for Intentional Exposure to Cannabis, 2017-2020. Seattle, WA: Addictions, Drug & Alcohol Institute (ADAI), University of Washington, February 2021.

Dr. Firth would like to acknowledge Katie Von Derau, RN, CPN, Managing Director of Washington Poison Center, for their insight and recommendation on how to interpret Poison Center data. Dr. Firth would like to thank Bia Carlini, PhD, MPH for providing input on the initial draft and review of the fact sheet. This report was produced with support from the Washington State Dedicated Marijuana Fund for research at the University of Washington.