In the December issue of Retail Pharmacy magazine, we continued the conversation around medicinal cannabis and the role of community pharmacists in this space, taking a specific look at cannabidiol (CBD) – its health benefits, the current regulations regarding its production and use, and what pharmacists need to know.
What is CBD?
Broadly speaking, two components make up the emerging area of healthcare referred to as medicinal cannabis: THC (or tetrahydrocannabinol), which is intoxicating, and CBD (or cannabidiol) which is not.
According to pharmacist Zeeta Bawa, research assistant and PhD candidate within the Lambert Initiative for Cannabinoid Therapeutics at the Brain and Mind Centre of the University of Sydney, these are “the two most well-studied active ingredients found in the Cannabis sativa plant”.
She adds that while evidence is still emerging, CBD has demonstrated health benefits, including “anxiolytic, anti-inflammatory, antipsychotic, anti-addiction and anticonvulsant properties”.
“CBD can be found in a wide variety of formulations, some of which include oils, capsules, wafers, flower (flos, plant material) and other oral products – for example, tablets, lozenges,” she said.
Dr Joe Kosterich, medical adviser to medicinal cannabis company Little Green Pharma says CBD is “one of the main cannabinoids in the cannabis plant”.
“It comes mainly as an oral form – oils or tablets – but also as dried flower,” he said. “There are [also] some sublingual formulations.”
Considering the regulations
Medicinal cannabis, and in this case, the use of CBD within Australian healthcare, is governed by tight regulations.
Regulatory authorities the Therapeutic Goods Administration (TGA) and the Australian Register of Therapeutic Goods (ARTG) have set in place restrictions related to the use of medicinal cannabis, which all healthcare professionals need to be aware of.
“Formulations containing mostly CBD have been largely available via Schedule 4 using the Authorised Prescriber (AP) and Special Access (SAS) schemes that are overseen by the TGA,” Ms Bawa said.
“Recently, Schedule 3 access has been approved but no CBD products have been registered with the TGA or are currently available in this schedule. It’s expected that this will happen sometime next year.”
Dr Kosterich adds that the TGA down-scheduled CBD to Schedule 3 in early 2021.
“This only applies to those formulations on the ARTG,” he said. “Currently there are none on this register, thus CBD is Schedule 4 and must be prescribed by a doctor.
“However, as CBD products are not on the ARTG, a doctor must get approval from the TGA to prescribe, in contrast to regular Schedule 4 drugs, which do not require authorisation.”
Despite the current regulations, the use of medicinal cannabis, specifically CBD in this case, is an evolving area of healthcare. As CBD offers health benefits, it’s an area in which pharmacists should be upskilling.
CBD: the health benefits
Referring to a summary provided by the TGA, Ms Bawa lists some of the evidence supporting the benefits of CBD for various health conditions:
- “There is reasonable well-established efficacy in paediatric epilepsy and anxiety from randomised controlled trials.
- “There is emerging evidence of efficacy in chronic pain and addictions from randomised controlled trials.
- “There are only pre-clinical/animal studies around the use of CBD for anti-inflammatory or neuroprotective effects.”
Ms Bawa continued: “The main uses for CBD have been chronic pain, anxiety, insomnia, neuropathic pain, cancer pain/symptoms and epilepsy. It should be noted that these uses are not always supported by robust evidence from clinical trials. This is not to say that CBD doesn’t work, but that we simply require more randomised controlled trials to confirm efficacy.”
She adds that currently, “CBD is often used when other treatment options are unsuitable or have failed”.
Conversations around CBD oils and products often refer to benefits in reducing inflammation. Ms Bawa says that while CBD has been “seen to help with modulating some of the inflammatory responses and pain associated with inflammation”, more “robust clinical trials are required to confirm these findings in humans”.
“The efficacy data of inflammation has largely come from pre-clinical and animal trials, which are an early marker of efficacy in inflammation,” she said.
Pharmacist and herbalist Gerald Quigley says that given its role within the inflammatory response pathways and the fact that “inflammation is the root cause of so many chronic diseases”, there’s an opportunity for CBD to help in this space.
He adds that evidence supports the role of CBD in aiding inflammatory conditions such as polymyalgia, fibromyalgia, osteoarthritis and rheumatoid arthritis.
“If you look at some mental health conditions that may involve inflammation in the brain, then CBD will play a role there,” he said. “In fact, … [CBD] has been used in an autism spectrum disorder study … there are some children whose autism has been resolved … so we know that it works as an anti-inflammatory.”
Similarly, when it comes to pain management, Ms Bawa says more “randomised controlled trials are required to truly understand the analgesic effects of CBD in various types of pain”.
“It’s important to [remember] that pain is a complex condition that varies in aetiology,” she said. “It’s not a one-dimensional condition, and therefore the treatment of pain is not simple either.”
Ms Bawa continued: “Despite the lack of robust clinical evidence, it [CBD] has certainly been prescribed a great deal for pain, and there’s a lot of interest in CBD as an alternative therapy. Some patients may find relief from their pain with CBD, while others may not.
“Currently, CBD is used on a case-by-case basis and is considered a last resort therapy or an ‘add-on’ therapy when conventional treatment options haven’t managed to control pain sufficiently. I recommend that patients speak to their doctors about using CBD for pain.”
While more clinical studies are needed, Dr Kosterich says numerous studies in the US have shown “reduced use of opiates when medicinal cannabis is introduced”, which may be a better alternative here, given the fact that “CBD is non-intoxicating and non-addictive”, he says.
“It’s important to point out that these studies generally include CBD and combinations of CBD and THC,” Dr Kosterich said. “It’s certainly the case that for some people, they can reduce other pain medications, and that reduction can be all the way down to stopping [this medication]. Currently in Australia, it [medicinal cannabis] can only be prescribed when other treatments have failed or caused adverse effects.”
Regarding the management of stress and anxiety, Ms Bawa says that “CBD has demonstrated anxiolytic effects in some clinical trials in doses of 300mg and above”.
“[This] is promising,” she said. “However, there are very few trials to confirm these effects … As I’ve mentioned, further high-quality trials are required to clarify the anxiolytic effects of CBD.”
Dr Kosterich says CBD, and combinations of CBD and THC, are “a viable option” for the management of stress/anxiety, as they are for pain management – and have “a more benign side effect profile than many currently used medications”.
“And [they’re ] non-addictive,” he said.
CBD precautions
Ms Bawa says “CBD generally has a good safety profile”, but she cautions that “it can interact with a number of medications”.
“This will, of course, depend on the dose and frequency of CBD use,” she said. “CBD can affect a number of enzymes in the liver, which will affect how various substances are metabolised. Therefore, care should be taken if patients are using other medications.”
In terms of drug interactions, Ms Bawa says CBD has been known to interact with “clobazam and sodium valproate”.
“CBD can also interact with warfarin, and recent research by the Lambert Initiative for Cannabinoid Therapeutics found a CBD and citalopram interaction,” she said.
According to Mr Quigley, CBD is generally safe and doesn’t have any significant side effects.
“It appears that the biggest issue with CBD and CBD oil is taste,” he said.
Ms Bawa agreed: “CBD is generally well tolerated, [although] some of the side effects of CBD can include fatigue, sedation and gastrointestinal upsets, including nausea, vomiting and diarrhoea,” she said. “However, these effects tend to happen at higher doses, and will depend on the dose and frequency of use.”
According to Dr Kosterich, CBD is also contraindicated in pregnancy and lactation, while “care needs to be taken in those with liver or kidney issues – albeit CBD is non-toxic to these organs”.
Reiterating the warnings regarding warfarin use, he says those considering CBD who are on warfarin will “need their INR levels monitored” as would be the case “with the addition of any new medication”. He adds that “care needs to be taken when adding it [CBD] to current medications that perform a similar role”.
“However, one can start at a low dose and titrate upwards slowly, in some instances while reducing other medications, if appropriate,” Dr Kosterich said. “In clinical practice, drug interactions are rarely a problem.”
The role of community pharmacy
When CBD products that comply with TGA regulations and are listed on the ARTG become available, this will be a space in which community pharmacies will have a role. It’s pertinent, therefore, for pharmacists to upskill in this area.
“It’s important for pharmacists to keep up to date with all of this,” Mr Quigley said. “I think they need to start learning about cannabis … they need to become educated in the latest work being done so that when these things come on the market, they’re ready to go because there’ll be people coming from everywhere wanting to give it [CBD] a try.”
He adds that it will also be important for pharmacists to “be supportive and engaging in customers’ requests”.
“[As pharmacists],” he said, “we should be able to confidently inform people, bearing in mind their history, their medications, their particular issues, their pain, and what effect [CBD] is having.”
Ms Bawa said: “Medicinal cannabis is an emerging area of pharmacy practice, and there’s a need for pharmacists to have knowledge about this drug class. This need is emphasised given the recent legislation, which will permit the Schedule 3 supply of low-dose CBD products.”
She continued: “In terms of Schedule 4 CBD supply, pharmacists should approach this medication as they would any other: Are the prescribed dose, frequency and indications suitable? Are there any drug interactions, contraindications or precautions? What counselling point should you provide?
“In terms of Schedule 3 CBD supply, pharmacists will be able to supply these products based on the indications approved by the TGA (these are yet to be determined). Over-the-counter supply of CBD by pharmacists will not be suitable for complex or unstable chronic conditions, and these customers will need to be referred to their doctor for further advice.
“I believe pharmacists will play a critical role in educating customers on CBD products and the available evidence, whether pharmacists decide to participate in supply or not.”
To read the feature in full, as it appears in the December issue of Retail Pharmacy magazine, visit: retailpharmacymagazine.com.au/magazine/retail-pharmacy-december-2022
