Medical Marijuana Use Linked To Abnormal Heart Rhythm, Study Finds

Medical marijuana use can lead to abnormal heart rhythm, a new study suggests. This new research has revealed that people taking cannabis for chronic pain have a slightly increased risk of arrhythmia, a condition where the heart beats too slowly, too quickly or irregularly.

In the past scientists had found a link between recreational cannabis use and cardiovascular disease, but there has been little research on medical use. The European Society of Cardiology researchers say their new study is important as a growing number of countries now permit medical cannabis as a treatment for chronic pain.

“Medical cannabis is now allowed as a treatment for chronic pain in 38 US states as well as several countries in Europe – such as Spain, Portugal, the Netherlands and the UK – and elsewhere around the world,” said Dr. Anders Holt from Copenhagen University Hospital.

“This means more and more doctors will find themselves prescribing cannabis, despite a lack of evidence on its side effects. I don’t think this research should make patients with chronic pain refrain from trying medical cannabis if other treatment has been inadequate,” said Dr. Holt.

“However, these results do suggest some improved monitoring may be advisable initially, especially in patients who are already at increased risk of cardiovascular disease.”

To get their results, published in the European Heart Journal, the team studied data from 5,391 Danish patients who had been prescribed cannabis for chronic pain.

This data was then compared with a group of 26,941 chronic pain patients who were not getting cannabis as a treatment.

They found that patients receiving medical cannabis had a 0.8 percent risk of being diagnosed with arrhythmia that required monitoring and possible treatment within 180 days of receiving cannabis. This risk was more than twice the risk for patients with chronic pain who were not taking cannabis.

Patients taking cannabis who were aged 60 and older and those already diagnosed with cancer or cardiometabolic disease, such as heart disease, stroke and diabetes, had the largest increases in their risk of arrhythmia.

Professor Robert Page from the University of Colorado said: “Therapeutically, these findings suggest that medical cannabis may not be a ‘one-size-fits-all’ therapeutic option for certain medical conditions and should be contextualized based on patient comorbidities and potential vulnerability to side effects.”

However, since this is an observational study, the authors have warned that there could be other important factors not reflected in the results. Dr. Holt concluded: “Despite our best efforts to make a balanced comparison, it can never be assumed that patients prescribed medical cannabis do not differ from patients not prescribed medical cannabis, and this could influence the results.

“We need much more research in this area. Before concluding anything, results from this study should be replicated in other countries and settings.

“It would also be interesting to understand if there are any links between long-term cannabis use and heart failure, stroke, or acute coronary syndrome.

“This would be an important area to clarify since chronic pain can persist for many years.”

Produced in association with SWNS Talker