Medical cannabis prescribing and consumption globally has been consistently on the rise in recent years, with cannabis-based medicinal products now being a relatively common treatment for chronic pain in several countries. In fact, chronic pain is the most reported reason for medical cannabis use around the world. Whilst there is growing evidence from randomised controlled trials and observational studies there is a need for further expert guidance on how to dose and administer medical cannabis safely and effectively.
A recent study using the findings of twenty global experts across nine countries aimed to determine consensus recommendations on the dosing and administration of medical cannabis for the treatment of chronic pain.
Design and Methods of the Study
The researchers and experts developed a multistage modified Delphi process to establish expert, consensus-based recommendations. The Delphi method involves systematic, interactive forecasting which relies on a panel of experts to reach a group opinion, or ‘consensus’. The modified Delphi process has been used extensively in health care settings to provide consensus-based recommendations on important clinical questions where randomised control trial data is lacking.
Upon recruitment, the task force completed a practice patterns survey to gain insights into how clinicians around the world were treating patients with medical cannabis. The selected experts were then provided with nine recent articles. An initial draft of 37 consensus questions was developed based on the practice patterns survey and reviewed for rationale and applicability to clinical practice by a nine-member scientific committee.
Following the review and approval from the scientific committee, an updated version was distributed to the other task force participants for their review of its rationale and applicability. The final version of the consensus questions was then distributed using an online survey.
To determine a consensus: For multiple-choice questions, a consensus was found if 75% or more of the responses supported an answer; for ranking questions, a consensus was found if 75% or more of the responses ae ‘agree’/’strongly agree’ or ‘disagree’/’strongly disagree’.
Results of the Study
Protocols for Dosing and Administration of Medical Cannabis for Chronic Pain
During the Delphi process, the experts developed routine protocols for the dosing and administration of medical cannabis with a focus on safety and what experienced prescribers observe in their practice to be effective. Three treatment protocols were developed: routine, conservative, and rapid.
The consensus suggested that medical cannabis may be considered for patients experiencing neuropathic, inflammatory, nociplastic, and mixed pain. Three routine treatment protocols were developed.
The Delphi process led to agreement that treatment may be initiated with 5mg of a CBD-predominant strain of cannabis and titrated up in increments of 10mg/day across two administrations every 2-3 days up to 40mg CBD per day. CBD was selected as the initiate cannabinoid to prioritise safety: CBD is highly tolerable, does not cause any psychotropic effects and has a low risk of adverse events. It was also agreed that the maximum amount of THC allowed in these CBD-predominant strains would be 1:10 THC to CBD.
If the maximum dose of CBD-predominant cannabis does not achieve the practitioner’s and patient’s treatment goals, an initiation of 2.5mg of THC per day may be considered. This should be titrated by 2.5mg every 2-7 days up to 40mg/day while maintaining the same CBD-predominant dose.
Finally, the consensus advice states that “clinicians are encouraged to titrate medical cannabis to the effects desired by each patient, as opposed to a specific CBD or THC dose. During the titration phase, the total daily dose of CBD and/or THC can be divided between two to four administrations.”
The conservative treatment protocol is designed to be considered for the treatment of patients who may be more sensitive to drug effects, such as clinically frail patients, those with complex comorbidities, polypharmacy, and/or mental health disorders may also require a conservative treatment approach.
The initiate dose in the conservative protocol is the same as for the routine protocol (5mg of CBD per day). However, it is then recommended that this dose be increased more slowly – by 5-10mg per day every 2-3 days up to 40mg CBD per day.
Again, if treatment goals are not achieved with the administration of CBD alone, the addition of THC can be initiated. The conservative protocol recommends initiating THC treatment with 1mg of THC and titrating by 1mg once per week up to a maximum of 40mg/day of THC while keeping the same CBD dose.
The rapid treatment protocol is designed to be considered for patients in need of urgent management of severe pain, palliation and for those with significant prior use of cannabis. For patients in palliative care, caution is advised when selecting a medical cannabis protocol as these patients may have higher frailty and a higher risk of terminal delirium, which would also make them suitable for the conservative treatment protocol.
The experts agreed that for rapid treatment, medical cannabis should be initiated at a balanced ratio of 2.5-5mg of both CBD and THC until patient goals are met or the dose reaches 40mg of THC.
For breakthrough pain, it is recommended that inhaled cannabis be considered due to its rapid onset and limited duration of action. A balanced THC:CBD or THC-predominant product may be used as needed.
Clinicians should consider following up with the patient every 2-4 weeks, however, in some cases, more frequent follow-ups may be required. Discontinuation of medical cannabis products should occur if the patient experiences intolerable, moderate, or severe adverse effects, the maximum recommended dose is reached and does not improve the patient’s condition, and/or the patient has misuse or diversion of cannabis.
The researchers note that future randomised control trials to examine the safety and efficacy of medical cannabis compared against current standards of care will be required to clarify whether the developed protocols result in improved patient outcomes.