More and more terminal patients and their families are calling upon cannabis to provide some symptom relief, and understandably so. Cannabis has been used for centuries to treat a broad assortment of symptoms and diseases. Over 100 known cannabinoids have been identified, each appearing to exert different effects. Most Americans are fairly familiar with the two main cannabinoids, tetrahydrocannabinol (THC) and cannabidiol (CBD). The psychoactive THC is the cannabinoid responsible for the “high” associated with marijuana and the majority of its negative effects. On the other hand, CBD, found in both marijuana and hemp, has non-rewarding effects and does not cause dependence.
Properties of CBD are believed to include anticonvulsant, muscle relaxant, anxiolytic, antioxidant, and anti-inflammatory effects. Thus, it may provide benefit in treatment of pain, anxiety, depression, insomnia, neurological disorders, epilepsy, inflammation, and cancer and is believed to produce an overall calming effect on the central nervous system.
With the wide variety of CBD products available in the United States, it is helpful for hospice nurses to have a general understanding of the variations between products, their expected adverse effects, and whether patients are using products appropriately. Understanding the following can provide hospice staff with a more comprehensive understanding of the important differences among the plethora of CBD products on the market and how best to advise patients to ensure appropriate use:
- CBD is derived from hemp, the variety of cannabis plant containing less than 0.3% THC content (by dry weight).
- Cannabinoids exert their effects in the human body via the endocannabinoid system naturally occurring in the body, with the most widely understood cannabnioid (CB) receptors being CB1 and CB2.
- CB1: mainly in the brain, central and peripheral nervous system, and tissues
- CB2: mainly in immune cells and peripheral tissues
- Three varieties of CBD products to understand include:
- Full spectrum hemp products: contain not only CBD but also other cannabinoids and terpenes, including up to 0.3% THC
- Broad spectrum CBD products: contain CBD, other cannabinoids, and terpenes, but all THC has been removed.
- CBD isolate products: contain only CBD (no THC, terpenes, or other cannabinoids)
- Terpenes are chemicals that determine how things smell and are the source of the aroma of cannabis. Over 120 terpenes have been found in cannabis, and the differences in terpene content among full spectrum and broad spectrum CBD products result in variations in taste/smell between products.
- Terpenes may contribute to the entourage effects of full spectrum hemp and broad spectrum CBD products, with the entourage effect being the interaction between terpenes, CBD, and other cannabinoids to potentially magnify their action on the body.
- Linalool is the terpene most responsible for the recognizable “marijuana smell” with its spicy and floral notes. It has strong sedative and relaxing effects.
- CBD has the potential for clinically significant interactions with prescription medications.
- Metabolized by CYP3A4 and CYP2C19
- Increases levels of medications metabolized by CYP2C19, including but not limited to:
- Citalopram, clobazam, diazepam, escitalopram, omeprazole, pantoprazole, and sertraline
- Use of CBD with valproate increases the risk of liver enzyme elevations
- CBD may elevate INR in patients on warfarin
- Some limitations to use of CBD in the hospice setting include:
- Lack of applicable clinical trials
- Lack of standardized products
- Only one FDA-approved CBD product: Epidiolex® for treatment of Lennox-Gastaut syndrome and Dravet syndrome
- Not enough evidence for prescribers to recommend CBD as an evidence-based option (therefore it would not be a hospice-covered product)
- May be cost-prohibitive for patient/family
- If patients choose to utilize CBD, encourage them to select a brand that has certification of product quality and potency of each batch produced, either providing publically posted lab results or providing them upon request
- Ideal routes of administration vary depending on symptom being treated
- For localized pain, a topical oil may provide the greatest likelihood of benefit
- For anxiety, oral, sublingual, or inhaled products may be most beneficial
- Understand that onset of action and duration of effects vary by route of administration
- Oral route:
- Onset: 30 minutes to 2 hours
- Duration of effect: up to 8 hours
- Low bioavailability due to extensive first pass metabolism
- Difficult to dose
- Sublingual route:
- Onset: 5 to 20 minutes
- Duration of effect: about 4 to 6 hours
- Topical route:
- Onset: 15 to 45 minutes
- Duration of effect: up to 2 hours
- Apply to areas of localized pain and massage in
- Inhaled route:
- Onset: within 10 minutes
- Peak effect: within 30 minutes
- Duration of effect: up to 2 hours
- Easier to dose than oral administration as effects are immediate
- Educate patients on potential adverse effects, including dry mouth, low blood pressure, light headedness, and drowsiness. Monitor patient appropriately after the addition of or change in CBD dosing.
- Due to the significant variation in CBD products available, encourage patients to continue using the same brand and variety of CBD product for consistency in effects.
- When patient/family chooses to initiate CBD products, recommend the following approach:
- Start at the lowest “recommended” total daily dosage (25 mg/day being a common starting point for oral products)
- Split this dose between 2-3 doses throughout the day
- Stay at the same dose for at least 3 days, evaluating response
- Adjust the dose until best dose is found, using the same product for consistency in effects
- Oral route:
References:
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