Cannabis and Your Heart

WHAT WE KNOW?
  • About 10% of cannabis users will become addicted; the likelihood of addiction to cannabis is higher for those who began using as a teenager.1

  • Use by adolescents is particularly problematic given cannabis' effect on brain development and mental health in this population...heavy use by teenagers is particularly worrisome and there is evidence that cannabis plays a role in potentiating nicotine addiction in this group.2

  • Heart rate and blood pressure are increased following cannabis consumption, forcing your heart to work harder.3

  • If cannabis is smoked, the capacity of blood to transport oxygen throughout the body, including to the heart, is reduced. The result is strain on the heart and a reduced ability to handle increased demands.4

  • The effects of long-term cannabis smoking on health remain unclear.5

  • Cannabis may interact with other medications. Cannabis users should speak to their pharmacist or other health care provider about potential interactions.

  • The long-standing illegal status of cannabis has made it a lower priority for health researchers and posed a hurdle to conducting studies. What we do know about the drug’s effects on health is not a lot. However, following legalization, we anticipate increased interest and evidence from the research community.

 
WHAT IS THE HEART INSTITUTE DOING/WHAT ARE WE TELLING PATIENTS?
  • Smoking cannabis is not a good idea for someone with ischemic heart disease.5

  • For individuals that do use cannabis, it is recommended they not smoke it – rather consider vaping it, or using oil or edible options.

  • If someone doesn’t use cannabis, there’s no reason to start now.

  • If someone would like help in stopping their cannabis, a list of local resources/cannabis cessation programs should be available and provided.

  • Edible products should be kept away from children and pets.

 

TOBACCO CESSATION AND CANNABIS?
  • Tobacco-use is most often consumed daily, multiple times per day. Cannabis is typically consumed differently and less frequently than tobacco. Therefore, the harms and consequences of short- and long-term use may be different.

  • Cannabis-use need not prevent a tobacco smoker from making a tobacco cessation attempt.

  • We should be asking patients being treated for tobacco dependence about their cannabis use; patterns of cannabis use may play a role in one’s ability to quit tobacco and/or stay quit (e.g., daily use versus infrequent recreational/social use). 

  • Cannabis-use may trigger tobacco smoking, just as can other substances (e.g., alcohol), and may undermine cessation efforts for those trying to quit or reduce tobacco.

  • Whether or not someone is a cannabis user, the same principles should be applied when treating their tobacco use (e.g., dosing of nicotine replacement therapy should be based on number of cigarettes per day).

 

REFRENCES
  1. Canadian Centre on Substance Use and Addiction. Canadian Drug Summary: Cannabis 2018. Available from: http://www.ccdus.ca/ResourceLibrary/CCSA-Canadian-Drug-SummaryCannabis-2018-en.pdf.

  2. Hurd YL, Michaelides M, Miller ML, Jutras-Aswad D. Trajectory of adolescent cannabis use on addiction vulnerability. Neuropharmacology. 2014;76 Pt B:416-24.

  3. American Medical Association. Report of the Council on Science and Public Health: Use of Cannabis for Medical Purposes. 2009.  Contract No.: CSAPH Report 3-I-09.

  4. Goyal H, Awad HH, Ghali JK. Role of cannabis in cardiovascular disorders. J Thorac Dis. 2017;9(7):2079-92.

  5. Volkow ND, Baler RD, Compton WM, Weiss SRB. Adverse Health Effects of Marijuana Use. The New England journal of medicine. 2014;370(23):2219-27.

 

MEDIA RELEASE AND INTERVIEWS
  1. University of Ottawa Heart Institute - June 2018 The Beat Issue 
  2. 1310 News Interview with Dr. Andrew Pipe - The Rick Gibbons Show-Hour 2, October 17, 2018
  3. CBC All in a Day Interview with Dr. Andrew Pipe - October 17, 2018