Cannabis is “one of the most widely used and controversial substances worldwide.”1 Although it is federally prohibited in the United States, 30 states and the District of Columbia have legalized some form of medical marijuana, and 8 states and DC have also legalized recreational marijuana for adults.2 According to the National Institute on Drug Abuse (NIDA), cannabis use in the United States has increased dramatically in the last decade from 14.5 million people (5.8% of people > 12 years of age) to 19.8 million (about 7.5%) in 2013.3

Marijuana use by older adults is also rising. A study by the National Survey of Drug Use and Health (NSDUH) found that from 2002-2014 the proportion of adults aged 50 to 64 who reported cannabis use in the past year more than tripled from 2.9% to 9.0%.4 Among adults age 65 or older, there was more than a ten-fold increase (from 0.2% to 2.1%).5  Data from a Substance Abuse and Mental Health Services Administration (SAMSHA) report reveal that as many as 132,000 older US adults use marijuana on a given day.6 Another study suggested that cannabis use among adults age 50 and above increased by 250% from 2006 to 2013.7

Compared with nonmedical use only, medical use has been found to be directly associated with older age, older marijuana initiation age, disability, Medicaid status, stroke diagnosis, poor self-rated health, anxiety disorder, daily or near daily marijuana use, residing in a medical marijuana legalization state, and perceived state legalization of medical marijuana.8 Interestingly, it was inversely associated with heavy alcohol use and nonmedical use of prescription stimulants and analgesics.8

“There are many reasons for the current increase in cannabis use among older adults,” said Walter Prozialeck, PhD, Professor of Pharmacology, Department of Pharmacology, Chicago College of Osteopathic Medicine, Midwestern University, Glendale, Illinois. “The needs of older adults are complex and it is important for clinicians to know what their patients are using,” he told MPR.

“Safer” Pain Relief

According to Dr Prozialeck, one of the most common reasons that older adults turn to marijuana is for pain relief, and as an alternative to opioids. “The need for more effective pain relief is important in today’s prescribing climate, in which prescribers are cutting back on opioid prescriptions in general, and particularly for older adults. Older people were one of the populations in which opioids were most widely used and now, since advanced age and sleep apnea are known to increase overdose problems, doctors are reluctant to prescribe –but older adults are a population with an increasing number of underlying pain conditions that they want relief from.” 

Dr Prozialeck noted that, while some older adults of the “aging hippie generation” might have used marijuana before during the 1960s and 1970s, a fair number are new users.

Thorsten Rudroff, PhD, assistant professor Department of Health & Human Physiology, University of Iowa, Iowa City, agreed, noting that many people age 50 and above first started using medical marijuana, primarily for pain relief.

Data on 138 older adult cannabis users presented at the 2018 annual meeting of the American Geriatric Society showed that most were able to partially or fully curb their use of prescription analgesic by using medical marijuana and 91% of respondents would recommend it to others.9 Another study found that Medicare Part D prescriptions filled for all opioids decreased in states with medical marijuana laws.10 A study of Medicaid prescription data concluded that medical marijuana laws and adult-use marijuana laws were associated with lower opioid prescribing rates.11

Sleep and Other Benefits

Older adults use marijuana for a variety of reasons beyond pain, including insomnia and anxiety.12

“I have a lifelong insomnia problem, due to early childhood trauma,” said Paige E, LCSW, a 75-year-old therapist who asked that her name not be used for this article. “I have tried the full array of psychotropic medications as well as sleeping medications, all of which were either ineffective or which gave me terrible side effects. Once my psychiatrist prescribed medical marijuana, my sleep improved and I’m less anxious. We were both surprised at how effective it turned out to be.” 

Additional reasons seniors turn to cannabis include glaucoma and chemotherapy side effects such as nausea (when relevant).12

Challenges of Cannabis Use in Older Adults

Two out of three older Americans have multiple chronic health conditions that generally require multiple prescription medications, increasing the risk of adverse drug effects, which can further endanger their health.13

“There’s a variety of competing medical issues in older individuals, as they start to have more physical problems and take an ever-increasing number of medications to manage those,” Dr Prozialeck observed. “Unfortunately, little is known about how various medications — both OTC and prescription drugs — interact with marijuana.” 

Some research suggests that marijuana may interact with several agents that are commonly prescribed to older adults via alteration of the liver’s cytochrome P450 enzyme system. Additionally, marijuana used together with other CNS depressants might have an additive sedative effect.14

Older people are more sensitive to many medications, as a result of age-related changes in body chemistry and brain function and cannabis is no exception, Dr Prozialeck noted. “There are no guidelines, no prescribing recommendations, virtually no research to guide practitioners or pharmacists in safe prescribing and drug-drug interactions in older adults.”

However, certain potential adverse effects of cannabis are known and should be on the radar of clinicians. “We know that prolonged use of cannabis can impair cognition,15 and cognitive impairment is already a concern in the elderly in many domains, including driving,” he warned. “Although some research16,17 suggests that cannabis can be helpful with symptoms of dementia such as agitation, cannabis has also been associated with psychotic disorders15 which is another concern in the elderly, particularly those with dementia.” 

Know Your Cannabinoids

Cannabis combines Δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in an approximately 1:1 ratio. The THC is the agent with psychoactive properties, while CBD affects anxiety and pain.“Cannabidiol is the more active pain reliever and doesn’t produce a ‘high,’ and there are many strains of medical marijuana that are bred to produce high cannabidiol and low THC,” said Dr Prozialeck.

With regard to obtaining the product, most states have a required procedure. “In Illinois where I live, the physician must submit a form to the Illinois Department of Public Health certifying that a patient has one of about 40 conditions that qualify them for the use of medical marijuana. When the department has reviewed the form and completed a background check, the patient receives a card allowing the use of medical marijuana, which can then be taken to a dispensary,” he explained.

Dr Rudroff noted that in Iowa, there are only 5 dispensaries that offer medical marijuana. The cardholder receives the name of these dispensaries. “I prefer this because the product can be dispensed in a more controlled way—in contrast to other states such as Colorado, where it has gotten out of hand, is less controlled, and there are dispensaries everywhere,” he said, adding that “a good dispensary should be able to let the patient know the ratio of THC to CBD.”

Delivery Routes

Recreational marijuana has several delivery routes, including inhalation (via cigarette, cigar, or herbal vaporizer) and consumption in the form of “edibles.” In states where recreational cannabis is legal, dispensaries sell a variety of cannabis-infused food items (eg, beverages, candies, cookies, honey sticks, butter, brownies, and cooking oils) Some package labels list the total milligrams of THC and CBD.1 Cannabis oils have also become popular and can be taken orally or used topically.1 Peters and Chien1 offer a thorough review of these delivery routes. Medical marijuana is available as an oil, pill, vaporized liquid and nasal spray, as dried leaves and buds, and as the plant itself.14

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Tips for Clinicians

Both experts offer tips to clinicians seeking to recommend medical marijuana to their patients.

Work closely with a prescriber

“Not all clinicians are prescribers, so if you are considering recommending medical marijuana to a patient, you need to work closely with a reliable and experienced physician who can prescribe and sign the person’s medical card,” Dr Rudroff said.

Be nonjudgmental

“Most older adults seeking to use medical marijuana are not ‘stoners,’ are not stereotypical members of the ‘stoner culture’ and are not seeking to get high,” Dr Prozialeck emphasized. He noted that most “are people from all walks of life and ages who simply need extra help with pain, insomnia, or other age-related conditions.”

Proactively ask about marijuana use

“Nonjudgmentally ask patients if they use recreational marijuana or if they use non-prescribed medical marijuana—what type they use and where they obtain it,” Dr Prozialeck advised. It might be helpful for the patient to bring specific information about what they are using so that the clinician can see the THC vs CBD content, he added.

Monitor patients closely

“Continue to be aware of the products patients are using, the other medications they are taking, and any adverse effects they might be having,” Dr Prozialeck suggested.

Advocate for more research

“There is a dearth of research regarding the effects of marijuana and clinicians should be advocates for more research and education in medical schools and CME activities regarding this important topic,” he concluded.

References

1.    Peters J, Chien J. Contemporary Routes of Cannabis Consumption: A Primer for Clinicians. J Am Osteopath Assoc. 2018 Feb 1;118(2):67-70.

2.    Governing the States and Localities. State marijuana laws in 2018 map. Available at: http://www.governing.com/gov-data/safety-justice/state-marijuana-laws-map-medical-recreational.html. Accessed: October 7, 2018.

3.    National Institutes of Health. National Institute on Drug Abuse (NIDA). Nationwide Trends. Available at: https://www.drugabuse.gov/publications/drugfacts/nationwide-trends. Accessed: October 7, 2018.

4.    University of Washington. Alcohol and Drug Abuse Institute. Marijuana use by older adults. Available at: http://learnaboutmarijuanawa.org/factsheets/olderadults.htm. Accessed: October 7, 2018.

5.    Substance Abuse and Mental Health Services Administration (SAMSHA). Results from the 2016 National Survey on Drug Use and Health. Available at: https://www.samhsa.gov/data/sites/default/files/NSDUH-DetTabs-2016/NSDUH-DetTabs-2016.pdf. Accessed: October 23, 2018.

6.    Substance Abuse and Mental Health Services Administration (SAMSHA). The CBHSQ Report. A day in the life of older adults: substance abuse facts. Available at: https://www.samhsa.gov/data/report/day-life-older-adults-substance-use-facts. Accessed: October 7, 2018.

7.    Han BH, Sherman S, Mauro PM, Martins SS, Rotenberg J, Palamar JJ. Demographic trends among older cannabis users in the United States, 2006–13. Addiction. 2017;112(3):516-525.

8.    Compton WM, Han B, Hughes A, Jones CM, Blanco C. Use of Marijuana for Medical Purposes Among Adults in the United States. JAMA. 2017 Jan 10;317(2):209-211. doi: 10.1001/jama.2016.18900.

9.    Agornyo P, et al. Older adults’ use of medical marijuana for chronic pain: A multi-site community-based survey. Presented at: American Geriatrics Society Annual Meeting; May 3-5, 2018; Orlando, Florida.

10. Bradford AC, Bradford D, Abraham AJ. Association Between US State Medical Cannabis Laws and Opioid Prescribing in the Medicare Part D Population. JAMA Intern Med. April 2018.

11. Wen H, Hockenberry JM. Association of Medical and Adult-Use Marijuana Laws With Opioid Prescribing for Medicaid Enrollees. JAMA Intern Med. 2018 May 1;178(5):673-679.

12. National Council for Aging Care (NCAC). The complete guide to medical marijuana for seniors. Available at: http://www.aging.com/the-complete-guide-to-medical-marijuana-for-seniors/. Accessed: October 20, 2018.

13. Centers for Disease Control and Prevention (CDC). The State of Aging and Health in America, 2013. Available at: https://www.cdc.gov/aging/pdf/state-aging-health-in-america-2013.pdf. Accessed: October 19, 2018.

14. Mayo Clinic. Marijuana. Available at: http://www.mayoclinic.org/drugs-supplements/marijuana/interactions/hrb-20059701. Accessed: October 23, 2018.

15. Shrivastava A, Johnston M, Tsuang M. Cannabis use and cognitive dysfunction. Indian J Psychiatry. 2011;53(3):187-91.

16. Lim K, See YM, Lee J. A Systematic Review of the Effectiveness of Medical Cannabis for Psychiatric, Movement and Neurodegenerative Disorders. Clin Psychopharmacol Neurosci. 2017 Nov 30;15(4):301-312.

17. Suryadevara U, Bruijnzeel DM, Nuthi M, Jagnarine DA, Tandon R, Bruijnzeel AW. Pros and Cons of Medical Cannabis use by People with Chronic Brain Disorders. Curr Neuropharmacol. 2017;15(6):800-814.