Domain 1: When to consider introducing cannabinoids in patients
with chronic pain taking opioids
The first domain asked questions about patient factors that may
influence the suitability of a patient for treatment with cannabinoids.
The key consensus findings are:
1) If a patient has a history of psychosis, is pregnant or
breastfeeding, or has had an adverse reaction to cannabinoids,
cannabinoids should be avoided. Although, when considering a patient
with a history of psychosis, THC appears to be the more significant
causal agent and CBD may in fact reduce
psychosis.45,46 Physicians may consider medical
cannabis in a patient: taking opioids at any morphine equivalent dose
(MED), not reaching chronic pain goals, experiencing opioid-related
adverse effects, and/or, displaying risk factors for opioid-related
harm. It is important to note that this consensus initiative does not
aim to suggest that all patients taking opioids should reduce their
opioids. In a recent commentary, the Centre for Disease Control
guidelines for opioid tapering were clarified to highlight that
clinicians should avoid increasing the opioid dosage to ≥ 90 MED, but
not necessarily discontinue opioids in patients on a high
dose.47 Dialogue and shared-decision making with the
patient and carefully evaluating the benefits and risks associated with
tapering and discontinuation of opioids is strongly encouraged. In
addition, before the introduction of any additional pharmaceutical
intervention, evidence-based psychological and physical therapy
interventions to reduce opioid use should be attempted and
maximized.48,49
2) There was consensus that no age restrictions were recommended for CBD
or THC use. With respect to CBD, the group quickly reached consensus as
high doses of CBD have been shown to be safe in children, albeit in a
patient population dissimilar to typical patients with chronic
pain.50,51 Conversely, there was debate surrounding
the minimum age recommendation for THC. When using THC, careful
consideration in the younger population should be made as the nervous
system is not fully developed until 25 years of age.52However, the consensus summit participants debated that if a young
patient is already on opioids it did not seem rational to withhold
cannabinoid therapy until they turn a specific age. Similarly, although
there was no maximum age agreed to, careful consideration must be given
when considering cannabinoids to the elderly, while also recognizing
that the elderly are particularly susceptible to the adverse effects of
opioids.