Induction dose of propofol in patients using cannabis

Eur J Anaesthesiol. 2009 Mar;26(3):192-5. doi: 10.1097/EJA.0b013e328319be59.


Background and objective: An estimated 150 million people worldwide use cannabis. The effect of cannabis on anaesthetic requirements in humans does not appear to have been studied.

Methods: In this prospective, randomized, single-blinded study, 30 male patients using cannabis more than once per week (group C) and 30 nonusers (group NC), aged 18-50 years, were induced with propofol 1.5, 2, 2.5, 3 or 3.5 mg kg. Additional doses were given when required. The primary outcome was the 50% effective dose of propofol and successful induction was determined by loss of consciousness with a bispectral index value of less than 60 and satisfactory insertion of a laryngeal mask. Propofol requirements to achieve these outcomes were recorded.

Results: The dose required to achieve the target bispectral index value was not significantly higher in group C, but group C required a significantly higher propofol dose to achieve laryngeal mask insertion (314.0 +/- 109.3 vs. 263.2 +/- 69.5 mg, P < 0.04). The estimated effective propofol induction dose in 50-95% of patients did not significantly differ between groups.

Conclusion: We conclude that cannabis use increases the propofol dose required for satisfactory clinical induction when inserting a laryngeal mask.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cannabis / chemistry*
  • Depression / drug therapy
  • Dose-Response Relationship, Drug
  • Humans
  • Male
  • Middle Aged
  • Propofol / pharmacology*
  • Propofol / therapeutic use
  • Treatment Outcome


  • Propofol