In the realm of modern medicine, where innovation and exploration often meet cautious contemplation, the integration of medicinal cannabis has sparked both hope and scepticism. In this thought-provoking article, Dr Quintner delves into the intriguing domain of medicinal cannabis and its implications for the elderly, shedding light on the delicate equilibrium between potential benefits and lurking risks.
Evidence derived from many studies has now made it clear that overall, compared to placebo, medicinal cannabis products provide small to very small reductions in pain intensity, improved physical functioning, and better sleep quality for patients with chronic pain.
Because the Therapeutic Goods Administration does not register these products, information provided by product sponsors may not have been independently reviewed.
Although there are standards for minimum manufacturing quality requirements, no standards exist about their clinical effectiveness or risk of adverse events (side effects). Moreover, different cannabis products may have varied effects. They are not available on the Pharmaceutical Benefits Scheme, and their cost can be prohibitive.
However, we do know that there is no safe level of medicinal cannabis use, and no studies have evaluated long-term side effects and complications.
Risks in the elderly population
Those considered to be elderly have reached the chronological age of 65 years and older. This section of the Australian population is growing. “Pain” is the main reason given by those who have been prescribed medicinal cannabis.
The number of prescribed medications tends to increase with age. As well as the ever-present risk of potential drug-drug interactions, it is important to remember that the metabolism of all drugs is slower in the elderly. This means that the elderly are less likely to tolerate the side effects of cannabis.
Possible interactions can occur between cannabis and commonly prescribed medications such as warfarin (blood thinner), anti-inflammatory drugs, cholesterol-lowering agents, and pain relievers.
Alcohol and cannabis are both central nervous system depressants. When used together, risk-taking behaviours are more likely to occur, such as speeding on residential streets, aggressive driving, intentional red light running, and texting whilst driving. Cannabis can be detected in the urine for between 10 and 30 days (or longer).
Chronic diseases that are commoner in the elderly population include neurodegenerative diseases (e.g., Alzheimer’s, Parkinson’s), cardiovascular diseases, immune system disorders, and musculoskeletal disorders. Problems with memory, cognition, and balance may be worsened by cannabis, thus placing the elderly at increased risk of falls, serious injury and inadequate safety. Cannabis products can hinder the ability to carry out daily tasks, such as driving a car. They are known to affect depth perception, divided attention, and reaction time.
According to the American Heart Association, people who use cannabis may be at increased risk of sudden death, heart attack, arrhythmia, and stroke.
Finally, attempts to stop cannabis can be challenging. Symptoms of withdrawal include anxiety, irritability, loss of appetite, indigestion, sweating, chills and tremors, restless sleep and nightmares.
The risks of harm to the elderly are such that a decision to prescribe cannabis should not be taken lightly. Due to medicinal cannabis products being unsanctioned, along with limited information about their safety and efficacy, prescribers are strongly advised to obtain informed consent prior to the commencement of treatment and to ensure proper monitoring levels are in place.
MEDICINAL CANNABIS AND THE ELDERLY: THE RISKS OUTWEIGH THE BENEFITS
By John Quintner, Consultant Physician in Rheumatology and Pain Medicine (retired)
Fischer B, Lindner SR, Hall W. Cannabis use and public health: time for a comprehensive harm-to-others framework. Lancet 2022;7:e808-e809.
Wang L, Hong PJ, May C, et al. Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials. BMJ 2021;374: doi: 10.1136/bmj.n1034.
Wolfe D, Corace K, Butler C, et al. Impacts of medical and non-medical cannabis on the health of older adults: findings from a scoping review of the literature. PLoS ONE 2023;18(2):e0281826. doi: 10.1371/journal.pone.0281826.
Links for further information
Guidance for the use of medicinal cannabis in Australia: https://www.tga.gov.au/resources/resource/guidance/guidance-use-medicinal-cannabis-australia-overview
Cannabis-based products. Medicinal cannabis at a glance: https://www.health.wa.gov.au/Articles/A_E/Cannabis-based-products