Are marijuana and seniors a bad combination?
Geriatrician Jennifer Watt opened the elderly man’s file. She was doing a follow up appointment with him after he’d come to an emergency room with delirium, a type of confusion that’s common in the elderly, and been admitted to the hospital. The notes said the issue had resolved itself, and it wasn’t clear what set it off. “There are lots of different risk factors for delirium, and he had things that would put him at risk,” she explains. But the trigger was unclear – until they started discussing his drug use.
He’d been looking for pain relief, and sought out some marijuana himself. “He began taking it, and got confused,” she says. “He was very honest with me when I asked. It was just that no one had asked before.”
Gabriella Gobbi, a professor of psychiatry at McGill University and psychiatrist at McGill University Health Centre, says she’s also seen several elderly patients with delirium caused by cannabis use.
We often hear about the potentially negative health effects of marijuana on young people, especially on developing adolescent brains. But some doctors, like Watt and Gobbi, believe we need more research on its effects on the elderly. They are concerned that we don’t know enough about its potential side effects, including confusion and an increased risk of falling.
Many seniors use cannabis for medicinal reasons, including pain and insomnia. Medical marijuana has been legal in Canada since 2001 – some dispensaries even offer seniors’ discounts. And its use is on the rise, with almost 130,000 Canadians registered to purchase it as of 2016, up from 7,900 in 2014. General use may also rise as the federal government moves to legalize marijuana by July 2018.
The elderly are significantly less likely to use marijuana than the regular population. But as cannabis becomes more generally accepted and aging Boomers hit retirement, more seniors may use it in the future. The U.S., which has legalized marijuana in eight states, has seen a rise in cannabis use in people over 50: in 2006/07, three percent of people in that age bracket said they’d used marijuana in the past year; in 2012/13, that number rose to five percent.
“I t’s use has become a very important issue,” says Gobbi. “More regulated research must be done in the elderly, to understand how cannabis can be used in this vulnerable population without side effects.”
The health effects of cannabis
There has been quite a bit of research into the health effects of marijuana in general, with more than 60 systematic reviews on the subject. Some studies have found it can help with treating nausea and vomiting from chemotherapy, reducing spasticity from multiple sclerosis, helping with Tourette’s syndrome, and reducing sleep disorders, though the evidence tends to be mid- to low-quality and vulnerable to bias. Cannabis is also often used for pain reduction, but the evidence around that is mixed.
There are some negatives: marijuana may increase the risk of testicular cancer and some mental health problems and it’s not safe during pregnancy. There have also been studies that suggest cannabis might be associated with problems like depression, anxiety, bladder cancer, bone loss or brain changes, among others, but the evidence around all of this is still inconclusive.
Elderly people may have distinct risks: A 2014 review on marijuana and older people pointed out that drowsiness and dizziness were two known side effects of marijuana that could contribute to falling in older people. It also pointed to an increased risk of arrhythmia.
Other studies have shown that marijuana might trigger a stroke in people with coronary artery disease. Marijuana’s cognitive effects could have a larger impact on older people who are already struggling cognitively. And cannabis can cause side effects when mixed with other medications, such as increasing the risk of bleeding, lowering blood pressure, and affecting blood sugar levels.
It’s difficult to research marijuana in the U.S., where it’s classified, federally, as a Schedule 1 narcotic. It’s much easier to do studies on it in Canada, but it still hasn’t gone through the same rigorous process as a regular pharmaceutical drug would have. “ Cannabis took this strange pathway,” says Gobbi. “I think that cannabis should go through clinical phases, as all drugs do, which would include testing on the elderly population.”
Effects on the elderly
The vast majority of cannabis research is done for the population in general and either doesn’t include the elderly at all or doesn’t report on them separately. A 2014 editorial in the Journal of the American Geriatrics Society made the argument that we need more research on the elderly and pot, as they’re likely to have adverse effects that are specific to them.
Mona Sidhu, a geriatrician who works out of Hamilton Health Sciences, knows this issue well. She routinely prescribes marijuana for seniors, mostly for pain management in people without cancer. “I fell into this,” she says. “I was asked to see patients that would be potential candidates for cannabis use, and having very little background knowledge, I didn’t know the potential.
“I learned from some other physicians, and after trying it on some seniors, and seeing how their fentanyl and morphine use started to reduce, I started prescribing it more.” She says it has helped many of her patients manage their pain, sleep better, and reduce anxiety.
She does start seniors on a lower dose than she uses for other people, she says, in the same way as she would modify the dose of a pharmaceutical drug. She also recommends seniors use a vaporizer or oral dose. She’s swayed by her personal experience, and by the anecdotal research out there supporting it. “Even though the high quality data is not out there, we should not ignore the anecdotal evidence that supports the use of marijuana,” she says.
Brian Kaskie, a researcher at the University of Iowa and the author of a 2016 paper that looked at the trends around marijuana usage in seniors, agrees. His paper pointed out that more older adults are using cannabis, and many of them are using it for medicinal reasons, and in place of prescription medications. While he acknowledges that may lead to some side effects, like falls, he’s excited about the possibility it brings, too. Many of these issues, like pain, “aren’t as relevant to people under 50,” he says. “The potential here is compelling.”
Fiona Clement, director of the Health Technology Assessment Unit at the University of Calgary and co-author of a review of the evidence around cannabis, looks at it differently. “If we held marijuana to the same standards as the other drugs we allow on the market, I don’t think it would meet the bar [for effectiveness as a treatment],” she says.
And everyone agrees that the evidence around all of this is still hazy. As Watt says, “At the end of the day, when it comes to knowing the potential benefits and harms and having that conversation with patients, right now we’re quite hindered by the lack of evidence.”
Medical Cannabis for Older Patients—Treatment Protocol and Initial Results
Older adults may benefit from cannabis treatment for various symptoms such as chronic pain, sleep difficulties, and others, that are not adequately controlled with evidence-based therapies. However, currently, there is a dearth of evidence about the efficacy and safety of cannabis treatment for these patients. This article aims to present a pragmatic treatment protocol for medical cannabis in older adults. We followed consecutive patients above 65 years of age prospectively who were treated with medical cannabis from April 2017 to October 2018. The outcomes included treatment adherence, global assessment of efficacy and adverse events after six months of treatment. During the study period, 184 patients began cannabis treatment, 63.6% were female, and the mean age was 81.2 ± 7.5 years (median age-82). After six months of treatment, 58.1% were still using cannabis. Of these patients, 33.6% reported adverse events, the most common of which were dizziness (12.1%) and sleepiness and fatigue (11.2%). Of the respondents, 84.8% reported some degree of improvement in their general condition. Special caution is warranted in older adults due to polypharmacy, pharmacokinetic changes, nervous system impairment, and increased cardiovascular risk. Medical cannabis should still be considered carefully and individually for each patient after a risk-benefit analysis and followed by frequent monitoring for efficacy and adverse events.
The recent interest and use of medical cannabis (MC) are growing substantially in many countries. The regulations on its use vary among countries, affecting medical practice and experience . Current public opinion is that cannabis has the therapeutic potential to treat and cure a long list of diseases, but there is a large gap between that opinion and the current evidence in the medical literature . Another common opinion is that MC is mainly used by young adults. However, the use of MC by older adults is increasing , and studies show variable prevalence, ranging from approximately 7% to more than one-third, depending on the country [4,5]. Recreational use of cannabis by older adults is also increasing substantially, especially in the United States .
Relief of suffering and promotion of functional status and quality of life are major goals of geriatric medicine. Chronic pain, Parkinson’s disease, depression, sleeping disorders, and malnutrition are all common among older adults [7,8,9,10,11,12]. Current medical treatments of these syndromes can have serious adverse events, frequently endangering patients’ health. For example, some non-steroidal anti-inflammatory drugs (NSAIDs) are associated with gastrointestinal bleeding, renal impairment, and cardiovascular adverse events . Sedative hypnotics can cause psychomotor impairment, dizziness, confusion, increased risk of falls, next-day somnolence, impairment of driving skills, orthostatic hypotension, and blood electrolyte impairment . Opioid treatment causes constipation, nausea, vomiting, drowsiness, delirium, sedation, anticholinergic effects, falls, and respiratory depression, which is the most serious potential adverse effect . Beyond individual factors, current concerns about opioid-related deaths have greatly influenced our thinking about pain management and medication treatment .
1.1. Efficacy and Indications for Medical Cannabis in Older Adults
The geriatric population may benefit from cannabis treatment for a variety of symptoms, such as chronic pain, sleep difficulties, tremor, spasticity, agitation, nausea, vomiting, and reduced appetite. Cannabis may also be useful in palliative care. However, currently, there is a dearth of evidence about the efficacy of cannabis in older adults for any of these symptoms. This has been emphasized in several reviews [16,17,18] and in large reports such as the report of the National Academies of Sciences in the United States  and the Information for Health Care Professionals in Canada .
1.2. Chronic Pain
Chronic pain is one of the most common indications for prescribing MC. The report by the National Academies of Sciences concludes that cannabis is effective for the treatment of chronic pain in adults . Despite this conclusion and a large number of studies, including randomized controlled trials, the efficacy for cannabis as a chronic pain medication remains in dispute . Pain relief is very often cited as a reason for MC use among older individuals. For example, 89.7% of the older patients in the Colorado MC registry listed pain as their primary or secondary condition . All the large studies that evaluated cannabis for pain have included older adults in the inclusion criteria, but their number was small, or they were not analyzed separately for safety and efficacy [21,22].
1.3. Parkinson’s Disease
Parkinson’s disease (PD) is a common neurodegenerative disease found mostly among older adults, which is caused by dopaminergic neuron loss. It is mainly characterized by motor symptoms that include bradykinesia in combination with resting tremor or rigidity . PD also has a distinct prodromal stage identified by non-motor symptoms, such as olfactory dysfunction, constipation, urinary dysfunction, depression, anxiety, and pain . Two small-scaled randomized controlled trials failed to demonstrate the efficacy of cannabis in treating the motor symptoms of PD [25,26]. However, cannabis might improve quality of life in PD and relieve other non-motor symptoms .
1.4. Sleep Difficulties
Approximately 50% of people above age 65 complain about sleeping difficulties, and there is an increase in sleep disturbances in old age . Care must be taken not to mistake geriatric sleep complaints for physiological aging, as these complaints are mainly attributable to medical, psychiatric and health-related burdens . It should be noted that sleep disturbances are among the most frequent complaints of cannabis withdrawal, and are a major cause for continued use after attempts to quit . Both pharmacological and non-pharmacological treatments are used to address sleep disorders among older individuals . A meta-analysis evaluating the therapeutic effect of cannabis on sleeping disturbances has not reached a decisive conclusion. The effects of cannabis on the sleep–wake cycle are also unclear , though some research suggests that cannabis might aid in sleep disorders due to its anxiolytic effect .
1.5. Nausea and Vomiting
A Cochrane review concluded that “Cannabis-based medications may be useful for treating refractory chemotherapy-induced nausea and vomiting” . A more recent review states that there is low-quality evidence that cannabinoids prevent nausea and vomiting as compared to other agents or a placebo . The only study that addressed this issue in older adults was in 1982, and it found no difference between tetrahydrocannabinol (THC) and prochlorperazine in reducing nausea and vomiting .
1.6. Post-Traumatic Stress Disorder (PTSD)
The efficacy of cannabis treatment for PTSD in older individuals was not evaluated thus far in any study. Several studies evaluated the efficacy of cannabis treatment for PTSD in younger adults, but these studies also failed to demonstrate a clear effect of MC treatment for these patients .
Dementia is a prevalent condition in older adults causing cognitive decline . Small studies that used Dronabinol, oral synthetic Δ 9 -THC, or an extract of THC from plants, showed it improved neuropsychiatric symptoms, agitation, nocturnal motor activity, sleep duration, and meals consumption in dementia patients, while only a few serious adverse events were observed [37,38,39].
However, a study conducted with Namisol, an oral tablet containing ≥98% natural ∆ 9 -THC, showed it did not reduce neuropsychiatric symptoms, agitation, activities of daily living, or improved quality of life in dementia patients .
1.8. Palliative Treatment
A recent systematic review and meta-analysis were unable to make any recommendation about the use of cannabis in palliative care after evaluating studies that included mainly younger adults and a small number of older adults .
2. Special Considerations and Precautions
2.1. Pharmacokinetics, Pharmacodynamics, and Drug Interactions
It is well known that aging is associated with substantial changes in pharmacokinetics and pharmacodynamics. For instance, hepatic drug clearance, as well as renal elimination, are both decreased in older adults. Furthermore, aging is associated with increased body fat and decreased lean body mass , which increases the volume of distribution for lipophilic drugs, such as cannabis. Two small studies evaluated the pharmacokinetics and pharmacodynamics of older adults who received an oral drug containing pure THC. These phase I and phase II trials included 12 healthy older adults and 10 older adults with dementia, respectively, and found smaller pharmacodynamic effects of THC in both groups, although the pharmacokinetic data showed substantial inter-individual variation [43,44]. Interaction between cannabis products and other drugs is also largely unknown, as the current evidence from human studies is sparse . Concomitant administration of cannabis with other drugs that influence the hepatic CYP family enzymes may greatly alter the metabolism of the cannabinoids . This issue is especially important in the geriatric population, where polypharmacy is common .
2.2. Nervous System Impairment
The common adverse effects experienced by patients due to cannabis use include dizziness, euphoria, drowsiness, confusion, and disorientation . These effects are particularly important in the geriatric population, which may have conditions such as dementia, frequent falls, mobility problems, hearing, or vision impairments . The long-term effect of adult cannabis use on cognition is unclear. Two systematic reviews showed evidence that long-term use of cannabis is associated with negative effects on some cognitive functions, but evidence of enduring negative effects was weak [49,50].
2.3. Cardiovascular Risks
The effects of cannabis on cardiovascular diseases are not yet well established. In recent years, however, there has been an increasing number of case series and reports concerning young, healthy recreational cannabis users who suffer from arrhythmias, myocardial infarction, and even sudden cardiac death . Direct causality has not been proven, but the implication is that care must be taken concerning older adults since they have more cardiovascular comorbidities and risk factors.
The acute cardiovascular effects of cannabis, based on studies performed on younger individuals, include an increase in sympathetic activity that causes an increase in heart rate, cardiac output, and myocardial oxygen demand. Tolerance of the effects of cannabis on heart rate develops rather quickly in young people .
This article aims to present a novel medical cannabis treatment protocol in older adults and the initial results from its use. The protocol will be presented in the Discussion segment of the manuscript.
3.1. Patients and Methods
Israeli medical cannabis regulations include a number of indications and recommendations for its use . We have adopted the general recommendations to suit the physiological and pathophysiological needs of the elderly. In 2017, NiaMedic established a specialized geriatric clinic to provide MC therapy within a comprehensive geriatric platform. We have followed 184 consecutive patients above 65 years of age prospectively who were treated with MC from April 2017 to October 2018. The patients were followed for at least six months since treatment initiation. The inclusion criteria were age of 65 years and above and any of the following indications for cannabis treatment: chronic cancer pain and non-cancer pain, Parkinson’s disease, sleep disorders, anorexia, post-traumatic stress disorder, spasticity, and palliative treatment. The exclusion criteria were severe cardiovascular diseases, such as heart failure or a recent major myocardial infarction, liver failure, psychotic comorbidities, and those with a history of addictions. The follow-up evaluation includes detailed questioning regarding adverse events, adherence to treatment, and its efficacy.
3.2. The Treatment Protocol
As previously mentioned, the regulations of cannabis and its products vary by country, which affects the clinical experience of physicians. In Israel, cannabis can be prescribed for the following conditions: nausea and vomiting due to chemotherapy treatment, cancer-associated pain; Crohn’s disease, ulcerative colitis; neuropathic pain; AIDS patients with Cachexia; multiple sclerosis, Parkinson’s disease, Tourette syndrome, epilepsy (both adult and pediatric population); palliative treatment; post-traumatic stress disorder . The initially approved dosing is 20 grams of cannabis compound per month (0.6 grams per day), with a cannabis product that contains the lowest concentration of active ingredients, but without limitation to the ratio of the different cannabinoids. The only cannabinoid-based medicine that is approved at the time of this manuscript preparation is Nabiximols, and its use is infrequent. Thus, we provide here our approach that is based on the available literature, data analysis, and our clinical experience with treating older adults with herbal cannabis, which includes the cohort above and previously published data . We offer many recommendations consistent with Minerbi et al. and MacCallum et al. [17,54].
Our study collected all the relevant clinical data as a part of the routine medical practice. Thus, Soroka University Medical Center institutional review board (IRB) Committee approved the protocol and waived the request for informed consent (confirmation number 0036-18-SOR). All clinical investigations were conducted according to the principles expressed in the Declaration of Helsinki.
We present here initial data from a cohort of patients who initiated MC therapy between April 2017 and October 2018. Most of our patients, 83.2% (n = 153) were 75 years of age or older, and 63.6% (n = 117) were females. The demographic characteristics, the comorbidities of the patients, and the indications for cannabis treatment are detailed in Table 1 . When we evaluated the patients after six months of MC treatment, we found that 58.1% were still using cannabis, 8.1% discontinued the treatment, 10.9% were lost to follow-up, and 17.9% did not complete six months of treatment by the time of the analysis. Of the 122 patients eligible to respond, 91.8% (n = 112) globally assessed the effect of cannabis on their general condition, with 84.8% of them reporting some degree of improvement ( Figure 1 ). Of the patients who were still treated with cannabis, 33.6% reported adverse events, the most common of which were dizziness (12.1%), sleepiness and fatigue (11.2%), dry mouth (5.6%), and psychoactive sensation (5.6%). Since well-established and evaluated protocols for treatment of older adults with cannabis do not exist, we have developed our own approach based on close follow-up of effects, adverse events, and slow titration.