Navigating Cannabis Use in Health Care Settings | ASHP Midyear

As more patients turn to cannabis for help managing a variety of symptoms, pharmacists and other health care providers must be prepared to navigate issues from cannabis-drug interactions to institutional policies, according to presenters at the American Society of Health-System Pharmacists 2024 Midyear Clinical Meeting and Exhibition.¹

Navigating cannabis use requires more than just an understanding of the endocannabinoid system. | Image credit: Tsareva.pro - stock.adobe.com

In April 2024, the Drug Enforcement Administration (DEA) made news when a proposal was announced that would move marijuana from Schedule I to Schedule III of the Controlled Substances Act. That change has not yet happened, rendering marijuana illegal at the federal level—despite what state-level regulations suggestion.

“As of May 2022, 38 states, the District of Columbia, Puerto Rico, Guam, and the US Virgin Islands have comprehensive laws and policies allowing for medical use of marijuana,” said Amanda Grady, PharmD, BCPS, DPLA, drug information clinical coordinator at the University of Kansas Health System in Kansas City, Missouri. Nine additional states, Grady added, allow limited use of medical cannabis, with only Kansas, Nebraska, and American Samoa in any extent.

The patchwork nature of state policies and regulations can create challenges for health care providers, with a variety of regulatory bodies, boards, and commission offering different levels of oversight.

“Every state does this differently, and it exposes users to risk,” Grady said. “If we don’t have a federal standard, then there aren’t streamlined ways to make sure that things are safe, efficacious, and reviewed appropriately.

This constantly changing landscape “puts the onus on health care institutions” to provide appropriate, effective care for patients who use cannabis—whether that use is medical or recreational in nature.

Clinical Considerations

In addition to tetrahydrocannabinol (THC) and cannabidiol (CBD)—two cannabinoids most patients are likely already familiar with—there are over 200 compounds in the cannabis plant, explained Ryan Hannan, PharmD, MBA, RPh, BCPS, clinical pharmacist at the Mayo Clinic in Minnesota. “One of the central themes is that the research is vast, [but] not very deep, as far as the benefits or risks associated with using cannabis products.”

READ MORE: The Nuances of Marijuana’s Potential Rescheduling

Along with THC and CBD, other potentially therapeutic cannabinoids include cannabinol (CBN), cannabigerol (CBG), cannbichromene (CBC), and tetrahydrocannabivarin (THCV). Each of these cannabinoids works on CB1 or CB2 endocannabinoid receptors, and each has a different potentially therapeutic effect.

The endocannabinoid system “is distributed in just about all the tissues in the human body,” Hannan explained. CB1 receptors are primarily concentrated in the central nervous system, with some receptors in the peripheral nervous system, reproductive glands, and inhibitor GABAergic and excitatory glutamatergic neurons. CB2 is primarily found in the immune system, in hematopoietic cells, and throughout the periphery, and both receptors can be found in cardiac, ophthalmic, and digestive tissues. The different locations of these endocannabinoid receptors explain the different effects—a “head high” or a “body high”—that cannabis users may talk about experiencing.

Anxiety, insomnia, and pain are the top 3 non-FDA approved indications for therapeutic cannabis use, but the list of conditions where patients may turn to therapeutic cannabis use is vast. However, the FDA has not yet approved a marketing application for the use of marijuana for the treatment of any condition: only 1 cannabis-derived drug (cannabidiol [Epidiolex]) and 3 marijuana-related drugs (dronabinol [Marinol], nabilone [Cesamet], and nabiximol [Sativex]) are available by prescription.

Anxiety

When it comes to anxiety, “CBD is the cannabinoid most associated with benefit, or perceived benefit, in practice,” Hannan said. What’s more, the dosing at which a patient experiences anxiolytic effects is “highly variable, ranging from 25 mg per dose all the way to up 800 mg per dose.” Epidiolex, the only FDA-approved prescription CBD, is supplied as a 100 mg/mL concentration in a 60 mL vial. “Someone using that 800 mg dose, even once a day, would need 4 bottles of the FDA-approved CVD in order to make it through the month,” said Hannan. “There is some concern about the cost being prohibitive.”

Insomnia

Hannan described the evidence around cannabis use for insomnia as “fairly sparse, but emerging.” Compounds that include multiple cannabinoids “can have unpredictable and sometimes even conflicting effects,” Hannan noted, explaining that THC has been linked with a reduction in REM sleep, while CBD can be either arousing or sedating, depending on the dose. Tachyphylaxis is also common: “Patients who are using these products on a regular basis—similar to what we would expect with patients using anticholinergic agents…will regularly experience a need to keep increasing those doses over time.”

A randomized, placebo-controlled, double-blind, proof-of-concept clinical trial is evaluating the safety and efficacy of ETC120, an oral oil solution containing 10 mg THC and 200 mg CBD in adults diagnosed with chronic insomnia. The study, CANSLEEP (ANZCTRN12619000714189), is ongoing and results have not yet been published.²

Pain

Patients who use cannabis for its analgesic effects have reported a reduction in the need to use opioids and analgesics with other mechanisms, said Hannan. “Neuropathic pain, in the available research, is the most promising for patients using cannabis for perceived medical benefits.”

“However, it is worth noting that although there are some reductions in opioid useage, there is no statistically significant reduction in opioid-related deaths in patients who are also using cannabinoids,” Hannan added.

Understanding Adverse Effects

Whether using medically or recreationally, patients who use cannabis can experience a wide range of adverse effects—ranging from nausea and vomiting to malaise and infection—and there are several important drug-drug interactions to consider. “[THC and CBD] both are highly protein-bound and fat-soluble drugs,” Hannan explained, “so it is worth noting that patients who use these products on a chronic basis can have some unpredictable kinetics.”

Both THC and CBD have numerous drug interactions, including with opioids; THC in particular can lead to an increased tolerance of opioids. “This comes into play when patients aren’t able to continue THC use when they’re in the hospital,” said Hannan, adding that these patients may have higher opioid needs compared with patients “who are not using exogenous cannabinoid products.”

Institutional Considerations

When considering cannabis use in health care settings, Hannah recommends a stepwise approach. Providers should start by considering the regulatory environment within their state. “Some hospitals have developed policies either specifically for cannabis products or have incorporated them into other policies, [such as] patient-supplied substances, herbal products, or controlled substance use.” It’s also important to know whether patients are using cannabis recreationally or for a medical indication, “either self-prescribed or through a state-approved medical cannabis program.”

Next, providers should consider the clinical implications of either starting or stopping cannabis use in an inpatient setting, “keeping in mind any comorbid diagnoses, chronic conditions, and the adverse effects that a patient may experience either with drug interactions from continuation or precipitating withdrawal, if usage was stopped.”

The final consideration is logistics, but Hannan concedes this “can be one of the trickiest steps to navigate.” Not only does product availability vary widely, but hospital pharmacies may not be able to secure a patient’s specific product. “Some states have very strict guidelines as far as who can obtain these products on behalf of the patient,” Hannan said. As a federally controlled substance, security should be considered, including logging and inventory, storage, and labeling, and documentation challenges in the electronic health record may be present.

“Billing could probably be a session [by itself],” Hannan said, noting that billing implications includes not only the administration of products, but “if any payer contracts prohibit usage of federally regulated or federally prohibited products.”

Ultimately, determining the role that cannabinoids may play in a patient’s treatment plan requires more than just an understanding of the endocannabinoid system. Pharmacists and other health care providers must understand current literature, regulations, and logistics, and engage in shared decision-making, to ensure patients are receiving appropriate care.

Follow along with our coverage of the 2024 ASHP Midyear Clinical Meeting and Exhibition here.

References

1. Grady A, Hannan R. High Maintenance: Joint decision making for cannabis in the healthcare setting. Presented at: American Society of Health System Pharmacists 2024 Midyear Clinical Meeting and Exhibition; December 8-12, 2024; New Orleans, LA.

2. Suarev A, Grunstein RR, Marshall NS, et al. Cannabidiol (CBD) and Δ⁹-tetrahydrocannabinol (THC) for chronic insomnia disorder (‘CANSLEEP’ trial): protocol for a randomised, placebo-controlled, double-blinded, proof-of-concept trial. BMJ Open. 202;10(5)e034421. doi:10.1136/bmjopen-2019-034421