Chronic Insomnia and Excess Cannabis Ingestion in an Older Adult—A Clinical Report of Complex Geriatric Care
Department of Psychiatry, Faculty of Medicine Dalhousie University Halifax Nova Scotia Canada
Division of Geriatric Medicine, Faculty of Medicine Dalhousie University Halifax Nova Scotia Canada
* Correspondence:Maia von Maltzahn (maia.vonmaltzahn@dal.ca)
Abstract
Cannabis use in older adults may have a broad range of effects in older adults impacting Mind, Mobility, Medications, Multi‐complexity, and what Matters Most.
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1Patient Story
“Mary” (fictional name to protect patient identity) is an 89‐year‐old woman with a history of chronic insomnia, anxiety, depression, and type 2 diabetes who presented to the hospital by emergency medical services (EMS) with an altered level of consciousness. She was found acutely confused by her next of kin and homecare worker, and EMS was contacted.
Mary's next of kin highlighted several life stressors contributing to a mental health crisis with worsening insomnia approximately 72 h prior to EMS arrival. Mary was provided cannabis indica gummies (Tetrahydrocannabinol (THC) 2 mg/piece, cannabidiol (CBD) < 0.1 mg/piece) to relieve her symptoms, with some effect the previous night. However, when her homecare worker arrived after the second night of trialing the cannabis gummy, they discovered her apartment in disarray; Mary's blood sugars were uncharacteristically elevated (> 20 mmol/L). They noted the remaining gummies in the package were gone, suspecting that possibly 4–6 had been ingested over approximately one and a half days.
Mary's home medications included lorazepam 1 mg PO at bedtime, zopiclone 3.75–7.5 mg PO at bedtime, melatonin 3–6 mg PO at bedtime, sertraline 25 mg PO once daily, pregabalin 75 mg PO once daily, and an unknown over the counter (OTC) sleep supplement taken regularly at bedtime. On scene, EMS documented 2 remaining cannabis gummies from a pack of 8 with unknown ingestion time. Paramedics report documented that Mary was confused (Glasgow Coma Scale 14), hypertensive (191–207/90 mmHg), and endorsed suprapubic pain. The remainder of her review of systems was unremarkable.
In the emergency department (ED), she underwent a non‐contrast computed tomography (CT) scan of the brain to rule out a structural cause for confusion. Shortly after CT, Mary experienced a single generalized tonic–clonic seizure, which was aborted using IV benzodiazepines. Subsequent blood work revealed diabetic ketoacidosis and no evidence of acetaminophen, alcohol, or salicylate ingestion. Serial electrocardiograms indicated new ST segment elevation, T wave inversion, and Q waves in anterior leads compared to prior studies. Bedside point of care ultrasound found left ventricular ejection fraction 40%–45% with anteroseptal akinesia extending into apical segments. Mary was started on aspirin 81 mg once daily, clopidogrel 75 mg once daily, and fondaparinux 2.5 mg once daily for anterior myocardial infarction.
Once stabilized, Mary was admitted to internal medicine with a diagnosis of delirium, felt to be precipitated by unintended excess cannabis ingestion and associated sedation. Secondary diagnoses included cystitis, diabetic ketoacidosis, and myocardial infarction. She was interviewed when her delirium cleared. Mary reported consuming half of a cannabis gummy to alleviate insomnia, for which she felt “desperate” to find a solution. She experienced no immediate effect and later consumed an estimated 4 to 6 gummies in a single sitting. She recalled losing consciousness, saying “I was out for 17 hours.”
With supportive care, Mary's mental status returned to baseline. Insomnia was improved by the addition of trazadone 25 mg PO at bedtime. Deprescribing of zopiclone and lorazepam was discussed with Mary, and the OTC sleep supplement was discontinued in hospital. Melatonin was continued during the hospital stay. Once Mary was determined to be medically stable, she was transferred to a transitional care unit within the hospital for 1.5 weeks, where she received inpatient physiotherapy to rehabilitate in hospital and resumed independent mobility with a two‐wheeled walker. After a total duration of hospitalization of 3 weeks, she was discharged home with personal care supports in place.
2Main Teaching Points
The intersection of Mary's lifelong mental health struggles (anxiety, depression) and seemingly intractable insomnia appeared to lead to cannabis use out of desperation to improve her sleep. The multicomplexity of managing chronic insomnia, polypharmacy, and potential risks associated with cannabis use in older adults was a key factor in why Mary's story is an important experience to recognize.
As this case demonstrates, even products with individually low doses of cannabinoids can present with a substantial safety risk without appropriate counseling. In our jurisdiction (Nova Scotia, Canada), THC concentrations of the indica strain in edible format can reach as high as 10 mg/piece with Mary ingesting edibles with a relatively lower dose of 2 mg/piece. As there may still be stigma associated with its purchase and use in older adults, clinicians should non‐judgementally review cannabis use, along with prescriptions, OTC medications, and supplements with patients. This includes weighing the risks related to common geriatric syndromes, which may be affected by cannabis use including: (i) falls secondary to dizziness/unsteadiness/sedation/orthostasis (Mobility), (ii) disturbances in cognition and mental status (Mind), and (iii) polypharmacy (Medications), especially given increased risks with concurrent use of sedatives or hypnotics [1, 2]. Figure 1 briefly describes the systemic health effects of cannabis in older adults, including increased risk of falls and polypharmacy [3].
3Discussion
Older adults are increasing their use of cannabis‐containing products since recreational and medicinal legalization [1]. In the first year following legalization in Canada, the proportion of adults aged 65 years and older who reported using cannabis in the preceding 3 months increased from 4.1% to 5.9% [1]. In the United States the annual prevalence increased from 2.4% to 4.2% between 2015 and 2018 with an estimated 2.7 million past‐year users [2]. Compared to the period before cannabis was legalized, ED visits increased among older adults in Canada (15.4 vs. 5.8 per 100,000 person‐years; adjusted IRR (incidence rate ratios), 2.00; 95% CI, 1.29–3.10) [4]. In the context of chronic insomnia, there is an under‐appreciated risk of cannabis products outside of reported cases of poisoning [4].
The preferred formulation will vary by individual and indication; however, there is some evidence to suggest edibles are a popular method of use by older adults [5], as was the case with Mary. Oral forms of cannabis may take up to 2–4 h to reach peak plasma concentration and bioavailability may be increased in older individuals with reduced hepatic and renal clearance and increased volume of distribution [6]. Effects of cannabis edibles can last up to 12 h after ingestion [7] with a typical intoxicating dose of edibles containing 10–30 mg of THC. We note that our patient consumed an estimated 8–12 mg of THC in one sitting. Furthermore, our patient articulated that she did not experience immediate onset of effects. This highlights a crucially important area for counseling in older adults to ensure they are aware of the potential for the delayed onset of effects.
There also exists the risk of polypharmacy and potentiation of sedative effects of medications used for mental health conditions and insomnia. In our patient, there may have been an interaction between zopiclone and THC, as both are metabolized by CYP3A47 [8]. Lorazepam and pregabalin do not have any documented direct pharmacokinetic interactions with THC, although they likely added to its sedating effect [8].
In current medical society guidelines, risks and benefits of cannabis in the context of sleep are not discussed, especially regarding co‐ingestion with sedating medications for insomnia. Cross‐referencing the clinical guidelines for the pharmacological management of insomnia in older adults from the American Academy of Sleep Medicine (AASM) [9] with the Beers Criteria [10], only low‐dose doxepin shows some overlap (Table 1). Cannabis is not discussed, likely due to limited high‐quality research, although these guidelines provide alternatives to cannabis for older adults seeking pharmacological options to manage insomnia.
| American Academy of Sleep Medicine (2017) [9] | American Geriatrics Society Updated Beers Criteria (2023) [10] | |
|---|---|---|
| Antidepressants (ex. Trazodone, doxepin) | Doxepin 3 mg or 6 mg for sleep maintenance (weak recommendation) Trazodone 50 mg (not suggested) | Avoid antidepressants with strong anticholinergic activity. Low dose doxepin (≤ 6 mg) has safety profile comparable to placebo. |
| Antihistamines (ex. Diphenhydramine) | Diphenhydramine 50 mg (Not suggested) | Avoid. |
| Antipsychotics (ex. quetiapine) | N/A | Avoid except in FDA‐approved indications. |
| Benzodiazepines | Temazepam 15 mg for sleep onset and maintenance (weak recommendation) Triazolam 0.25 mg for sleep onset (weak recommendation, benefits approximately equal to harms) | Avoid. May be appropriate for seizure disorder, severe generalized anxiety disorder, REM sleep behavior disorder, ethanol withdrawal, benzodiazepine withdrawal |
| Melatonin | Not suggested (based on trials of 2 mg) | N/A |
| Orexin Receptor Antagonists | Suvorexant 15 mg for sleep maintenance (weak recommendation) | N/A |
| Ramelteon | Dose of 8 mg in adults with sleep‐onset insomnia (weak recommendation) | N/A |
| Z‐Drugs (ex. zolpidem) | Eszopiclone 2 mg for sleep onset and maintenance (weak recommendation) Zolpidem 10 mg for sleep onset and maintenance (weak recommendation) | Avoid. Similar side effects to benzodiazepines with minimal improvement in sleep latency or duration |
Ultimately, available evidence reflects an uncertain benefit‐to‐risk ratio of cannabis use in older adults. Its use may be associated with higher frequencies of mental health issues, substance use, and acute healthcare use [1]. To best support older adults, their clinicians, and to tailor public health messaging, further research with balanced assessment of benefits and harms around cannabis use in this population is needed. This includes more detailed guidance around use in patients with comorbid mental health conditions and insomnia.
Disclosure
The authors have nothing to report.
Conflicts of Interest
The authors declare no conflicts of interest.
Acknowledgments
The corresponding author confirms that all listed authors contributed significantly to the manuscript. The authors wish to acknowledge the use of the generative artificial intelligence platform, Napkin AI (https://www.napkin.ai/), for the development of Figure 1 in the manuscript. The authors wish to thank the patient who consented to having this case written for scholarly purposes.