Overdose And Accidental Ingestion

This page provides information related to accidental ingestion of marijuana by both humans and pets, with specific information on edibles. Since the body processes THC differently when it is eaten rather than inhaled, edibles present a higher risk for overdose.


Users often expect effects experienced with inhaled THC, BUT...

  • Onset of effects is delayed for edibles.
  • Effect of edibles is stronger than people realize.
  • Edibles create a longer high than expected.
  • THC with no CDB can cause extreme paranoia.
  • Edibles are attractive to naive users and tourists in states where recreational marijuana is legal.

The deaths of three people in Colorado have been tied to edible recreational marijuana overdose.

Drugged Driving

  • 2012 meta-analysis: acute cannabis consumption significantly increases the risk of motor vehicle accidents (odds ratio 1.92).
  • Study of airplane pilot performance showed impairment in all variables 24 hours after smoking one THC cigarette, although pilots reported no awareness of impaired performance.

Source: Asbridge M., Hayden J.A., Cartwright J.L. Acute cannabis consumption and motor collision risk: systemic review of observational studies and meta-analysis, February 9, 2012.

THC and Alcohol

  • Both are central nervous system depressants
  • Additive, possible synergistic effect
    • Additive: 1+1=2
    • Synergistic: 1+1=5
  • Very low levels of both can cause major impairments
    • 0.035 blood alcohol content + low doses of THC equal approximately 0.09 - 0.14 blood alcohol content level of impairment (Courtesy of Sarah Uhrfer, Chematox, Boulder, CO)