New-onset arrhythmia risk higher in patients prescribed cannabis for chronic pain

8th September 2022

The risk of a new-onset arrhythmia appears higher among patients prescribed cannabis for chronic pain compared to those not using the drug

Patients prescribed medicinal cannabis products for the management of chronic pain are at a higher risk of a new-onset arrhythmia according to the findings of a retrospective study by researchers from Gentofte University Hospital, Denmark.

Cannabis is a generic term used to denote the several psychoactive preparations of the plant Cannabis sativa and according to the World Health Organisation, around 147 million people, 2.5% of the world population, consume cannabis every year.

There are recognised medical benefits from using cannabis and in 2018, the Danish government began a medical cannabis pilot program and by 2021, it was estimated that medical cannabis was used by approximately 1,500 patients on a quarterly basis.

Nevertheless, cannabis use is associated with adverse cardiovascular effects, including tachycardia and an elevation of blood pressure, effects that were first noticed in the early 1970’s.

Moreover, in a 2020 systematic review, the authors concluded that use of cannabis was associated with an increased risk of new-onset cardiac dysrhythmia, which, though rate, may be life-threatening.

In the current study, which was presented at the 2022 European Cardiology Society Congress, the Danish researchers sought to get a better understanding of the cardiovascular side effects of medical cannabis and in particular, arrhythmias in those using cannabis for pain relief.

There are currently only three cannabis products available for prescription in Denmark, dronabinol, cannabinoid, and cannabidiol, which can be inhaled, eaten, or sprayed in the mouth.

The researchers looked at patients prescribed these three drugs for chronic pain, between 2018 and 2021 and propensity-matched them, based on age, sex and pain diagnosis, on a 1:5 basis, with chronic pain patients not prescribed cannabis.

Both cannabis users and controls were followed for 180 days and their risks of new-onset cardiovascular conditions were compared.

New-onset arrhythmia and cannabis use

A total of 1.6 million patients with a median age of 60 (63% women) were included in the analysis. Cannabis use was reported for cancer (17.8%), arthritis (17.1%), back pain (14.9%), neurological diseases (9.8%), headaches (4.4%), complicated fractures (3%) and other diagnoses (mainly unspecified pain), 33.1%.

The absolute risk of new-onset arrhythmia was 0.86% among medical cannabis users compared with 0.49% in non-users (relative risk = 1.74). The risks of new-onset acute coronary syndrome and heart failure was no different between cannabis users and control and were similar for each chronic pain condition and each type of medical cannabis.

Lead author for the study, Dr Nouhravesh said: ‘The absolute risk difference was modest and it should be noted that a higher proportion of those in the cannabis group were taking other pain medications, namely non-steroidal anti-inflammatory drugs, opioids and anti-epileptics, and we cannot rule out that this might explain the greater likelihood of arrhythmias.’

She added: ‘This study indicates that there may be a previously unreported risk of arrhythmias following medical cannabis use. Even though the absolute risk difference is small, both patients and physicians should have as much information as possible when weighing up the pros and cons of any treatment.’

Citation
Cardiovascular risk following cannabinoid treatment for patients with chronic pain

Cannabis use not associated with higher incidence of respiratory-related hospital visits

4th July 2022

Cannabis use does not seem to be associated with more respiratory-related emergency department visits compared non-users of the drug

Cannabis use is not associated with more respiratory-related visits to an emergency department in comparison to those who do not use the drug although it is associated with a greater proportion of overall emergency department visits.

This was the main conclusion of a propensity-matched study by a group of researchers from Ontario, Canada.

Cannabis (or marijuana) is the most commonly used addictive drug after tobacco and alcohol. The use of cannabis is associated with respiratory problems such as chronic bronchitis symptoms and large airway inflammation and in fact, heavy use may lead to airflow obstruction.

Despite this evidence of adverse respiratory effects, a 2018 systematic review concluded that there was low-strength evidence that smoking cannabis was associated with cough, sputum production, and wheezing and that there was insufficient evidence of an association between use of the drug and obstructive lung disease.

Nevertheless, one study has suggested that daily cannabis smoking, even in the absence of tobacco, is associated with an elevated risk of health care use for various health problems.

With some uncertainty over the respiratory effects of cannabis, in the present study, the Canadian team wanted to examine the magnitude of the association between the use of cannabis and adverse respiratory-related emergency department visits.

They conducted a retrospective analysis linking health survey and health administrative data for residents of Ontario. Individuals who self-reported any use of cannabis (the exposed group) within the past year were matched 1:3 (to increase the sample size) with control individuals, which were those who self-reported no use of the drug.

The primary outcome for the study was a respiratory-related emergency department visit or hospitalisation which included both upper and lower respiratory tract infections, respiratory failure, asthma or COPD as the reason for presentation at the hospital. As a secondary outcome, the team assessed all-cause emergency department visits.

Cannabis use and respiratory-related hospital visits

A total of 35,114 individuals were included in the analysis, of whom, 6,425 with a mean age of 32.2 years (38.8% female) were self-reported cannabis users. Overall, 42.5% of those using the drug did so less than once a month with a much smaller proportion (10.5%) reporting daily use.

The odds of a respiratory-related emergency department visit or hospitalisation was not significantly different between the exposed and control group (odds ratio, OR = 0.91, 95% CI 0.77 – 1.09, p = 0.32). Despite this, there was a greater odds of all-cause emergency department visits among those who used cannabis (OR = 1.22, 95% CI 1.13 – 1.31, p < 0.0001).

The most frequent reason for the emergency visits among those using cannabis was for acute trauma (15.1%) although interestingly, this was followed by respiratory problems (14.2%).

The authors concluded that while there were no differences in the proportion of respiratory-related hospital visits between the two groups, all-cause hospital visits were significantly higher among those who. self-reported cannabis use.

They added that based on these findings, recreational use of the drug should be discouraged.

Citation
Vozoris NT et al. Cannabis use and risks of respiratory and all-cause morbidity and mortality: a population-based, data-linkage, cohort study BMJ Open Respir Res 2022

Cannabis used for symptom relief in nearly half of women with breast cancer

25th October 2021

Cannabis use for the relief of symptoms in women with breast cancer was reported by 42% those in a US survey of an online health group.

An anonymous survey of cannabis (CB) use found that 42% of women with breast cancer were using it for the relief of symptoms, according research conducted by the online support group, Breastcancer.org, Pennsylvania, US. The use of medicinal CB among those with cancer is not new and has previously been reported by nearly a quarter of respondents with a range of different cancer and mostly for pain relief. In addition, other work has found that 1 in 5 patients of those with cancer admitted to taking CB during chemotherapy. Although in the US, federal law states that the possession of cannabis is illegal, except within approved research settings, as of May 2021, 36 states and four territories allow for the medical use of cannabis products and in many cases, this can be for cancer.

For the present study, the researchers developed their survey and posted it online and members of Breastcancer.org were invited to participate through messaging boards, social media and email newsletters. The survey collected demographic data as well as breast cancer variables e.g., type, stage and treatment status, together with information on their use of cannabis such as timing of use in relation to therapy, e.g., before, during or after treatment, products used, sources and perceptions of the safety of cannabis.

Findings

A total of 612 completed surveys were available for analysis from women with a mean age of 57 years. A total of 64% of respondents reported being very or extremely interested in the medicinal use of cannabis, with the most common source of information being websites (67%) and family and friends (56%). However, only 39% had discussed the use of CB with their physician.

Overall, 42% (257/612) reported having used cannabis although only 23% (58) mentioned that this was specifically for medical purposes, with the remainder using it both medically and for recreational purposes. Among the 257 respondents using cannabis, 79% had used it alongside conventional treatment and 54% reported using it after the completion of therapy. The most common reasons for taking cannabis were for the relief of pain (78%), insomnia (70%),  anxiety (57%), stress (50%) and nausea/vomiting (46%). Moreover, 75% of those using CB believed that it was extremely or very helpful, at relieving their symptoms. Of more concern, was that 57% of those using cannabis stated that this was because they found no other way of treating their symptoms and how 49% stated that they were using CB in the belief that it could treat their cancer.

Interestingly, 78% of respondents somewhat or strongly agreed, that cannabis should be viewed similarly to other plant-based medicines with 71% stating that the benefits of cannabis outweighed its risks.

Commenting on their findings, the researchers noted how the use of CB during therapy was a concern, given the limited data available on interactions. In addition, they suggested that medical providers should discuss the risks and benefits of using CB in those with cancer.

Citation

Weiss MC et al. A Coala-T-Cannabis Survey Study of Breast Cancer Patients’ Use of Cannabis Before, During, and After Treatment. Cancer 2021